1
00:00:01,040 --> 00:00:04,200
Speaker 1: Welcome to you Stuff you Should Know from House Stuff

2
00:00:04,240 --> 00:00:12,520
Speaker 1: Works dot com. Hey, and welcome to the podcast. I'm

3
00:00:12,600 --> 00:00:15,760
Speaker 1: Josh Clark with Charles W. Chuck Bryant with Jerry Rowland

4
00:00:16,280 --> 00:00:19,479
Speaker 1: with me Josh Clark, Mr. Stuff you Should Know featuring

5
00:00:19,600 --> 00:00:22,759
Speaker 1: Josh Clark's about to say you never introduced yourself and

6
00:00:22,800 --> 00:00:27,200
Speaker 1: then you done did it twice three three times? Oh yeah,

7
00:00:27,280 --> 00:00:30,120
Speaker 1: you always introduce your but you never say your last name.

8
00:00:30,160 --> 00:00:34,680
Speaker 1: I think that's extruct me. John. No, I say I'm

9
00:00:34,760 --> 00:00:37,320
Speaker 1: Josh Clark, do you Yeah? Every time I should listen

10
00:00:37,360 --> 00:00:41,519
Speaker 1: to the Sometimes that explains the glazed overlook in your

11
00:00:41,560 --> 00:00:49,599
Speaker 1: eyes whenever we start um bridges. Yeah, is that your intro? Ye?

12
00:00:50,760 --> 00:00:53,120
Speaker 1: I like them. Maybe we can add like a scat

13
00:00:53,200 --> 00:00:56,640
Speaker 1: drummer on top of that. We have that kind of

14
00:00:56,760 --> 00:00:59,720
Speaker 1: um when we're doing uh listener mail, there's a little

15
00:00:59,720 --> 00:01:02,800
Speaker 1: bit of oh yeah, well that's not scat drumming. I

16
00:01:02,800 --> 00:01:05,880
Speaker 1: would say that's more of a shuffle mhm scots like

17
00:01:07,800 --> 00:01:10,040
Speaker 1: yeah like that. Yeah, you should get Hodgment to scat

18
00:01:10,040 --> 00:01:14,520
Speaker 1: for you sometime. He's got a lot of boot boot

19
00:01:14,520 --> 00:01:20,000
Speaker 1: bidus going on when he's scatting any jazz hands. No, No,

20
00:01:20,040 --> 00:01:27,959
Speaker 1: it's not exactly Manhattan Transfer level. He's intermediate. Yeah uh

21
00:01:28,040 --> 00:01:32,160
Speaker 1: yeah so again, Princess. Yeah, you know, I bet we're

22
00:01:32,200 --> 00:01:35,760
Speaker 1: gonna hear from some folks because there are bridge enthusiasts,

23
00:01:36,720 --> 00:01:38,959
Speaker 1: which I think is kind of neat. Yeah. Well, I

24
00:01:38,959 --> 00:01:42,680
Speaker 1: mean they're like modern marvels of engineering, and actually there's

25
00:01:42,720 --> 00:01:47,120
Speaker 1: some ancient marvels of engineering too, as far as they are.

26
00:01:47,280 --> 00:01:52,120
Speaker 1: Um yeah, there you Basically I was talking to our

27
00:01:52,200 --> 00:01:58,680
Speaker 1: pal um Adam the architect o, the bridge builder. No, yeah, uh,

28
00:01:58,680 --> 00:02:02,520
Speaker 1: he's a building builder. We're a building designer. I don't

29
00:02:02,520 --> 00:02:04,440
Speaker 1: know if he actually knows how to build the buildings.

30
00:02:04,480 --> 00:02:06,120
Speaker 1: He just knows how to tell other people how to

31
00:02:06,160 --> 00:02:10,280
Speaker 1: build that. Adam can't swing a hammer. He was saying that,

32
00:02:10,440 --> 00:02:17,720
Speaker 1: um uh the um. Basically, the structural engineers who designed

33
00:02:17,720 --> 00:02:21,480
Speaker 1: bridges are just straight up geniuses. Like it requires a

34
00:02:21,600 --> 00:02:25,040
Speaker 1: basically a genius to factor in all of this stuff. Yeah,

35
00:02:25,040 --> 00:02:28,600
Speaker 1: anyone can design a building, you know, there's just four

36
00:02:28,639 --> 00:02:31,200
Speaker 1: walls and a bunch of floors. Put a roof on it.

37
00:02:31,600 --> 00:02:36,880
Speaker 1: Bridge though it's different. Yes, right, there aren't walls really, Um,

38
00:02:37,040 --> 00:02:39,360
Speaker 1: there can be bridges of Madison County they had walls.

39
00:02:39,440 --> 00:02:41,920
Speaker 1: Oh yeah, they have walls. I was going to mention

40
00:02:41,960 --> 00:02:44,600
Speaker 1: the bridges of Madison County. Yeah, I love those that

41
00:02:44,600 --> 00:02:49,520
Speaker 1: that'd be a beam bridge, I guess, yeah, with a trust, right,

42
00:02:50,120 --> 00:02:53,960
Speaker 1: the top trust was the top trust film a through

43
00:02:54,000 --> 00:02:58,160
Speaker 1: trust through trusts, and then below that. If they were

44
00:02:58,200 --> 00:03:00,280
Speaker 1: below it would be a deck trust. But don't know

45
00:03:00,280 --> 00:03:01,760
Speaker 1: if that counts as a trust. It's more just like

46
00:03:01,800 --> 00:03:04,120
Speaker 1: a house on top of the bridge. I bet their

47
00:03:04,160 --> 00:03:07,560
Speaker 1: structural support there. May thought it was mainly just to

48
00:03:07,639 --> 00:03:09,639
Speaker 1: keep the rain off of you when you crossed the bridge,

49
00:03:09,639 --> 00:03:12,720
Speaker 1: like just an extra little thank you for crossing the bridge.

50
00:03:12,760 --> 00:03:15,120
Speaker 1: I thought it was just to draw in Lackey tourists

51
00:03:15,639 --> 00:03:19,640
Speaker 1: who wanted to have their picture made. Another famous bridge,

52
00:03:20,040 --> 00:03:22,880
Speaker 1: the one that the Headless Horseman couldn't cross in the

53
00:03:23,000 --> 00:03:27,040
Speaker 1: legend of Sleepy Hallow. Oh yeah, wouldn't that a bridge? Sure?

54
00:03:27,320 --> 00:03:31,120
Speaker 1: Trolls of under bridges that draw bridges are pretty cool.

55
00:03:31,639 --> 00:03:35,360
Speaker 1: Have you ever seen Maximum Overdrive? The beginning of that movie? Um,

56
00:03:35,400 --> 00:03:38,240
Speaker 1: it's been many, many years. I saw it again. I

57
00:03:38,280 --> 00:03:41,240
Speaker 1: saw it again very recently, like this year, and it

58
00:03:40,480 --> 00:03:43,480
Speaker 1: is it's maybe better than it was before. It holds

59
00:03:43,560 --> 00:03:47,480
Speaker 1: up as a crappy movie. Still. Yeah, the whole soundtrack

60
00:03:47,560 --> 00:03:49,160
Speaker 1: is a C D C by the way, which you

61
00:03:49,200 --> 00:03:52,240
Speaker 1: should love the whole sound I do love that, and

62
00:03:52,280 --> 00:03:55,080
Speaker 1: I do remember that. And didn't Stephen King direct that,

63
00:03:56,120 --> 00:03:58,840
Speaker 1: which he doesn't do much, right, No, but maybe it's

64
00:03:58,840 --> 00:04:01,720
Speaker 1: the only one is definitely far interesting. But there's a

65
00:04:01,720 --> 00:04:06,720
Speaker 1: great draw draw bridge scene in there. Uh did someone

66
00:04:06,800 --> 00:04:11,480
Speaker 1: jump it jump the span as it raised? No? I

67
00:04:11,520 --> 00:04:14,280
Speaker 1: think their car fell into their truck felling. Okay, because

68
00:04:14,360 --> 00:04:17,080
Speaker 1: usually the drawbridge scene is like I can make it.

69
00:04:18,560 --> 00:04:24,520
Speaker 1: Uh No, this one was you're all doomed and uh,

70
00:04:24,600 --> 00:04:27,919
Speaker 1: let me also recommend Budapest for bridges. You mean I

71
00:04:27,960 --> 00:04:30,240
Speaker 1: went to Budapest a couple of New years as ago. Yeah,

72
00:04:30,279 --> 00:04:32,919
Speaker 1: I went there like twenty years ago. Okay, so yeah,

73
00:04:33,120 --> 00:04:35,720
Speaker 1: you know the bridges are amazing that I think like

74
00:04:35,839 --> 00:04:40,680
Speaker 1: five because they connect the two sides, yeah, Buddha and Pest, right,

75
00:04:41,000 --> 00:04:43,880
Speaker 1: and each one is totally different, like it's just a

76
00:04:43,920 --> 00:04:48,760
Speaker 1: completely different design. Yeah, and they're just all gorgeous. Yeah,

77
00:04:48,960 --> 00:04:51,120
Speaker 1: let's just start with a bunch of bridge recommendations. I'm

78
00:04:51,160 --> 00:04:56,280
Speaker 1: going to recommend the City of Pittsburgh baseball game there,

79
00:04:56,320 --> 00:04:59,359
Speaker 1: and it's just just gorgeous. Those beautiful bridges that you

80
00:04:59,400 --> 00:05:02,320
Speaker 1: can see from the baseball stadium and the river. That

81
00:05:02,400 --> 00:05:07,080
Speaker 1: was when we were a Toyota commercial ring. Right. Yeah,

82
00:05:07,120 --> 00:05:11,159
Speaker 1: I stayed in the hotel and just eight um sog

83
00:05:11,200 --> 00:05:14,440
Speaker 1: copenny r no chicken sog. Right, it's just like a

84
00:05:14,600 --> 00:05:17,160
Speaker 1: quarter of it. But you can see the baseball stadium

85
00:05:17,160 --> 00:05:20,359
Speaker 1: out your hotel window. Yeah. And I saw some bridges

86
00:05:20,400 --> 00:05:22,520
Speaker 1: to Yeah, you walk across the bridge to get there.

87
00:05:22,920 --> 00:05:27,960
Speaker 1: Really swe did what else any other bridges, well, Brooklyn Bridge,

88
00:05:28,880 --> 00:05:31,520
Speaker 1: Golden Gate Bridge, this are like the famous ones. They're

89
00:05:31,560 --> 00:05:34,920
Speaker 1: barely even worth mentioning. Yeah, but the Brooklyn Bridge is

90
00:05:35,760 --> 00:05:38,679
Speaker 1: for your money. It's which is free. It's a pretty

91
00:05:38,720 --> 00:05:41,080
Speaker 1: great thing to do to walk across it. It's it's

92
00:05:41,240 --> 00:05:43,920
Speaker 1: just beautiful. I've never done that. You should do it.

93
00:05:44,080 --> 00:05:47,360
Speaker 1: Even the Geico Lizard did it, and I haven't. That

94
00:05:47,440 --> 00:05:49,800
Speaker 1: guy's like Australian or something. Well, maybe we should just

95
00:05:49,839 --> 00:05:52,680
Speaker 1: animate you and have you walk across it. Uh. One

96
00:05:52,680 --> 00:05:55,640
Speaker 1: more thing if you want to know more about the

97
00:05:55,640 --> 00:05:58,440
Speaker 1: Brooklyn Bridge, I don't remember which one we talked about it,

98
00:05:58,480 --> 00:06:01,640
Speaker 1: and but there is a really cool documentary about the

99
00:06:01,680 --> 00:06:06,279
Speaker 1: Brooklyn Bridge and it's building by Ken Burns. Oh wow,

100
00:06:06,400 --> 00:06:08,719
Speaker 1: I believe it's on Netflix. I'll have to check that

101
00:06:08,760 --> 00:06:13,320
Speaker 1: out then, yep, because I like cain Burns and Brooklyn bridges,

102
00:06:14,480 --> 00:06:19,839
Speaker 1: all right, you ready? Uh yeah, man, So bridges have

103
00:06:19,920 --> 00:06:22,640
Speaker 1: been around for a very long time. This article is

104
00:06:22,680 --> 00:06:26,080
Speaker 1: by Robert Lam and another dude named Michael Morrissey together.

105
00:06:26,520 --> 00:06:29,560
Speaker 1: I believe they were locked away in a closet for

106
00:06:29,640 --> 00:06:33,160
Speaker 1: like a couple of months while they worked this out together. Well,

107
00:06:33,320 --> 00:06:35,200
Speaker 1: he the one of the first ones that talking about

108
00:06:35,200 --> 00:06:40,320
Speaker 1: ancient bridges that they mentioned in here, the Arcadeco Bridge

109
00:06:40,600 --> 00:06:44,240
Speaker 1: in ancient Greece. Did you see that thing? It's really neat.

110
00:06:44,279 --> 00:06:47,200
Speaker 1: I mean it still stands. It's a three thousand year

111
00:06:47,200 --> 00:06:50,680
Speaker 1: old bridge, and uh, it's just kind of cool to

112
00:06:50,720 --> 00:06:55,640
Speaker 1: think about, you know, ancient civilizations and ancient times. People said,

113
00:06:55,680 --> 00:06:58,880
Speaker 1: well I want to get over there, and I'm here,

114
00:06:59,760 --> 00:07:02,240
Speaker 1: and so let's build something to do that. I need

115
00:07:02,279 --> 00:07:05,760
Speaker 1: something to walk on or drive my card over that.

116
00:07:05,839 --> 00:07:09,040
Speaker 1: Si Um, I just saw that. I saw the world's

117
00:07:09,080 --> 00:07:13,280
Speaker 1: oldest bridge that's still in use. Um is in Turkey

118
00:07:13,320 --> 00:07:20,160
Speaker 1: over the Mulis River, I believe from eight Do you

119
00:07:20,200 --> 00:07:23,360
Speaker 1: know what that's how it's constructed. It is a single

120
00:07:23,520 --> 00:07:28,520
Speaker 1: It is a single stone slab. Archy. No, it is

121
00:07:28,560 --> 00:07:32,480
Speaker 1: a stone slab, single arch. Yeah that makes sense. Yeah,

122
00:07:33,280 --> 00:07:39,600
Speaker 1: very basic. Yeah, but the arch it's super old. But

123
00:07:39,720 --> 00:07:43,880
Speaker 1: it's still in use today because whoever figured it out

124
00:07:44,080 --> 00:07:46,680
Speaker 1: came upon this very elegant solution to a lot of

125
00:07:46,720 --> 00:07:49,720
Speaker 1: problems that a bridge poses. Because, as you were saying,

126
00:07:50,120 --> 00:07:52,880
Speaker 1: when when you come upon like a river or creek

127
00:07:52,960 --> 00:07:54,560
Speaker 1: or something, you say, I'm on this side and I

128
00:07:54,600 --> 00:07:55,880
Speaker 1: need to be on the other side, so I need

129
00:07:55,920 --> 00:07:59,720
Speaker 1: something to walk across. Yeah, okay, that's a basic solution.

130
00:07:59,760 --> 00:08:01,960
Speaker 1: But the further and further you get, the more and

131
00:08:02,000 --> 00:08:07,960
Speaker 1: more problems. Like, as bridge builders say, most span more problems. Yeah,

132
00:08:08,000 --> 00:08:09,480
Speaker 1: I guess what we should have said is I want

133
00:08:09,480 --> 00:08:13,200
Speaker 1: to walk across and live. I want to walk all

134
00:08:13,240 --> 00:08:16,000
Speaker 1: the way across, right, I don't want to fall down. No,

135
00:08:16,080 --> 00:08:18,000
Speaker 1: I don't want to get halfway across and have it snapped.

136
00:08:18,400 --> 00:08:24,440
Speaker 1: So over the years, as people have come upon problems

137
00:08:24,520 --> 00:08:27,160
Speaker 1: where you are going to build a bridge that will

138
00:08:27,240 --> 00:08:30,480
Speaker 1: snapping and kill you, they've come up with solutions to

139
00:08:30,720 --> 00:08:33,520
Speaker 1: prevent that from happening. That's pretty much the pursuit of

140
00:08:33,600 --> 00:08:36,680
Speaker 1: bridge building is coming up with ways to prevent a

141
00:08:36,720 --> 00:08:39,040
Speaker 1: bridge from collapsing, and a lot of trial and error

142
00:08:39,040 --> 00:08:41,800
Speaker 1: over the years, you know, and a lot of real

143
00:08:42,120 --> 00:08:46,400
Speaker 1: significant disasters. In fact, there's a Time magazine slide show

144
00:08:47,160 --> 00:08:51,600
Speaker 1: um called worst Bridge Collapses in Past one years, um,

145
00:08:51,640 --> 00:08:53,839
Speaker 1: and it's got all these photos of collapse bridges and

146
00:08:53,920 --> 00:08:57,120
Speaker 1: little descriptions and the number of fatalities and everything. But um,

147
00:08:57,120 --> 00:09:00,400
Speaker 1: it's it's really interesting all these different bridges of lapsed

148
00:09:00,400 --> 00:09:03,080
Speaker 1: and failed for all these different reasons. Well and after

149
00:09:03,160 --> 00:09:06,480
Speaker 1: each one, uh, it's very sad, of course, but after

150
00:09:06,559 --> 00:09:09,400
Speaker 1: each one someone goes, oh, well we should do this

151
00:09:09,559 --> 00:09:13,200
Speaker 1: for the next one. We should not forget that bolt

152
00:09:13,440 --> 00:09:15,800
Speaker 1: next time. Well, that's that could be human Ara, True,

153
00:09:15,880 --> 00:09:20,360
Speaker 1: that's happened. Yeah, I'm sure. All right. So should we

154
00:09:20,400 --> 00:09:25,600
Speaker 1: start off with the bats be A t s. Beams, arches, trusses,

155
00:09:26,080 --> 00:09:31,560
Speaker 1: and suspensions are the main components of the structural components

156
00:09:31,559 --> 00:09:35,080
Speaker 1: of a bridge. It's very simple, that's it. That's all

157
00:09:35,120 --> 00:09:38,000
Speaker 1: you need to know to construct your own bridge. And

158
00:09:38,080 --> 00:09:41,240
Speaker 1: with these four things you can make almost any kind

159
00:09:41,280 --> 00:09:45,560
Speaker 1: of bridge. Um. We're gonna cover mainly beam bridges, arch bridges,

160
00:09:46,000 --> 00:09:50,520
Speaker 1: trust bridges, suspension bridges, and then the super cool looking

161
00:09:51,000 --> 00:09:55,360
Speaker 1: cable stayed bridge. It is super cool, probably my favorite

162
00:09:55,360 --> 00:09:58,000
Speaker 1: looking bridge in the world that I came across and

163
00:09:58,040 --> 00:10:01,840
Speaker 1: reach researching. This is a cable stayed bridge, the one

164
00:10:01,880 --> 00:10:05,440
Speaker 1: that's in the article. Oh yeah, they look like look

165
00:10:05,520 --> 00:10:09,240
Speaker 1: like sales gorgeous, the big triangles rising up. It's lovely.

166
00:10:09,880 --> 00:10:11,679
Speaker 1: But they look a little more modern to me. They

167
00:10:11,679 --> 00:10:16,000
Speaker 1: don't have that classic architecture like the Brooklyn Bridge does,

168
00:10:16,120 --> 00:10:18,079
Speaker 1: or like the Tower Bridge in London. Yeah. I think

169
00:10:18,080 --> 00:10:21,000
Speaker 1: that's why I like it. Yeah, you like the modern look. Yeah, yeah,

170
00:10:21,160 --> 00:10:26,319
Speaker 1: you're a modern guy. I'm super mod alright. Um. They

171
00:10:26,360 --> 00:10:28,400
Speaker 1: point out in the article, which is very key. What

172
00:10:28,480 --> 00:10:31,880
Speaker 1: you talked about. The span of the bridge is the

173
00:10:31,920 --> 00:10:35,600
Speaker 1: distance between the supports, and that's where um, that's where

174
00:10:35,600 --> 00:10:38,839
Speaker 1: it all goes down. Basically, Yes, that's got to be strong,

175
00:10:38,920 --> 00:10:41,480
Speaker 1: there be those are something that every single bridge has

176
00:10:41,600 --> 00:10:44,679
Speaker 1: is a span and at least one support most likely

177
00:10:44,760 --> 00:10:51,440
Speaker 1: to Yeah you know, um, and there's different The reason

178
00:10:51,559 --> 00:10:55,200
Speaker 1: that there are different types of bridges because different bridge

179
00:10:55,240 --> 00:11:00,560
Speaker 1: designs that that bats designs what is it, beams, arches, trusses,

180
00:11:00,559 --> 00:11:06,320
Speaker 1: and suspension. They provide stability for varying span lengths. So

181
00:11:06,400 --> 00:11:08,720
Speaker 1: like a beam, if you have like a fifty ft

182
00:11:09,240 --> 00:11:13,760
Speaker 1: um span, just put a a like a very long

183
00:11:13,800 --> 00:11:16,880
Speaker 1: log over over the span and there you go, there's

184
00:11:16,880 --> 00:11:19,559
Speaker 1: your bridge. But as you get further and further along,

185
00:11:19,920 --> 00:11:22,520
Speaker 1: you have more and more problems supporting that span, so

186
00:11:22,600 --> 00:11:26,040
Speaker 1: you need different types of solutions, and the different length

187
00:11:26,040 --> 00:11:29,000
Speaker 1: of the span calls usually for a specific type of

188
00:11:29,040 --> 00:11:32,280
Speaker 1: bridge design. Yeah, and generally it it'll I mean there's

189
00:11:32,280 --> 00:11:35,200
Speaker 1: a lot of overlap, of course, but UM beam bridges

190
00:11:35,240 --> 00:11:37,680
Speaker 1: tend to be the shortest, followed by arch bridges and

191
00:11:37,720 --> 00:11:42,720
Speaker 1: then suspension bridges, and I think those UM the cable

192
00:11:42,720 --> 00:11:45,040
Speaker 1: stayed bridge is is kind of a suspension bridge, so

193
00:11:45,080 --> 00:11:48,120
Speaker 1: that counts. It's like a kind of a variation that

194
00:11:48,920 --> 00:11:51,480
Speaker 1: can be very long as well. Yeah, not quite as

195
00:11:51,520 --> 00:11:54,160
Speaker 1: long as suspension bridges though from what I understand, and

196
00:11:54,280 --> 00:11:58,080
Speaker 1: this UM, the suspension bridge affords the longest span. Okay,

197
00:11:58,240 --> 00:12:02,440
Speaker 1: so you've got a big long span, it's it's suspension time. Yeah.

198
00:12:02,480 --> 00:12:06,560
Speaker 1: And they're also super expensive. Yeah, suspension bridges because all

199
00:12:06,640 --> 00:12:08,880
Speaker 1: the bridge builders know that you've got a log span

200
00:12:09,000 --> 00:12:10,800
Speaker 1: that you're trying to cross, you probably got some deep

201
00:12:10,800 --> 00:12:12,880
Speaker 1: pockets and they're gonna milk you for it. Oh yeah,

202
00:12:12,920 --> 00:12:16,680
Speaker 1: every penny. Yeah. Yeah, Like you need a suspension bridge

203
00:12:16,760 --> 00:12:20,280
Speaker 1: I'm your guy. Um, all right, so let's talk about

204
00:12:20,679 --> 00:12:23,240
Speaker 1: there are a lot of different forces that can act

205
00:12:23,280 --> 00:12:26,520
Speaker 1: on a bridge to make it not as stable. Um.

206
00:12:26,960 --> 00:12:30,280
Speaker 1: Will cover a few of the other ones later, but

207
00:12:30,320 --> 00:12:34,520
Speaker 1: the main two here early on our tension and compression.

208
00:12:35,440 --> 00:12:37,360
Speaker 1: And the very easy way to think about these two

209
00:12:37,440 --> 00:12:40,160
Speaker 1: things is tension is like if you if you and

210
00:12:40,200 --> 00:12:42,040
Speaker 1: I are pulling a rope, like you're on one end

211
00:12:42,080 --> 00:12:44,360
Speaker 1: and I'm on the other, We're gonna pull that sucker tight,

212
00:12:45,120 --> 00:12:48,959
Speaker 1: and uh, I'm gonna fall over due to your massive strength.

213
00:12:49,200 --> 00:12:52,160
Speaker 1: I'm pretty huge, but um, there will be some tension

214
00:12:52,160 --> 00:12:57,320
Speaker 1: in that rope. Yeah, f do you fall down? Yeah?

215
00:12:57,400 --> 00:13:00,000
Speaker 1: And I'd start laughing if there would be tension. Sure.

216
00:13:00,160 --> 00:13:03,600
Speaker 1: The tension is the lengthening of something. Compression is the

217
00:13:03,640 --> 00:13:06,360
Speaker 1: shortening of something, Yeah, like a spring collapse. Right. So

218
00:13:06,400 --> 00:13:08,800
Speaker 1: it's easy to visualize when you're talking like springs and

219
00:13:08,880 --> 00:13:10,640
Speaker 1: ropes and that kind of thing. But if you're talking

220
00:13:10,679 --> 00:13:13,680
Speaker 1: about just a single deck of a bridge, which you

221
00:13:13,720 --> 00:13:17,160
Speaker 1: think of as one piece, Um, it's tough to it

222
00:13:17,480 --> 00:13:21,280
Speaker 1: starts to get tough to visualize it until you realize

223
00:13:21,320 --> 00:13:23,480
Speaker 1: that you have to look at like a bridge deck

224
00:13:23,800 --> 00:13:27,480
Speaker 1: like the roadway on the bridge as really having a

225
00:13:27,559 --> 00:13:31,480
Speaker 1: top and a bottom. Yes, and forces, Well, the compression

226
00:13:31,559 --> 00:13:34,439
Speaker 1: acts in the downward motion on the top, and the

227
00:13:34,480 --> 00:13:38,640
Speaker 1: tension acts from the underneath coming up on the bottom. Right,

228
00:13:38,679 --> 00:13:42,880
Speaker 1: So the bottom of the bridge, underneath it, of the

229
00:13:42,960 --> 00:13:46,839
Speaker 1: deck is going to be spread out under the force

230
00:13:46,840 --> 00:13:50,960
Speaker 1: of tension. We're on top where it's being pushed down compressed.

231
00:13:51,679 --> 00:13:55,360
Speaker 1: That's compression. Yeah, and they kind of in a weird way,

232
00:13:55,400 --> 00:13:58,880
Speaker 1: work together. Even though they're sort of opposite things, they're

233
00:13:58,920 --> 00:14:02,840
Speaker 1: definitely related, right. Uh. And what will happen is if

234
00:14:02,880 --> 00:14:07,520
Speaker 1: these uh, if you aren't a very good bridge builder, um,

235
00:14:07,640 --> 00:14:11,559
Speaker 1: buckling will occur when it's compressed on the top, and

236
00:14:11,920 --> 00:14:16,560
Speaker 1: snapping can occur on the bottom when tension is at work.

237
00:14:16,880 --> 00:14:19,000
Speaker 1: That's right. It all sounds very confusing, but if you

238
00:14:19,120 --> 00:14:21,480
Speaker 1: just I gotta do is like put your hand out

239
00:14:21,520 --> 00:14:24,640
Speaker 1: and look at it, you know, and so or if

240
00:14:24,680 --> 00:14:27,120
Speaker 1: you take and push down on your hand or on

241
00:14:27,160 --> 00:14:31,000
Speaker 1: your hand, right, you know what I'm saying, like that, yeah,

242
00:14:31,120 --> 00:14:35,680
Speaker 1: like that. Um, the whole thing becomes very very evident

243
00:14:35,920 --> 00:14:39,320
Speaker 1: when you look at a beam bridge, right, the most

244
00:14:39,360 --> 00:14:41,680
Speaker 1: basic form of a bridge, like if you dropped a

245
00:14:41,680 --> 00:14:44,720
Speaker 1: log over a river, right, and this this thing. Um.

246
00:14:44,840 --> 00:14:47,400
Speaker 1: This article used the example of like taking a pair

247
00:14:47,400 --> 00:14:50,280
Speaker 1: of milk crates and putting like a two by four

248
00:14:50,320 --> 00:14:53,480
Speaker 1: across them. Right, if you put like a bowling ball

249
00:14:54,600 --> 00:14:57,200
Speaker 1: on a bowling ball stand so it doesn't roll around, Yeah,

250
00:14:57,200 --> 00:15:00,840
Speaker 1: that'd awkward on top of them, on top, right in

251
00:15:00,840 --> 00:15:03,920
Speaker 1: the middle of your two by four, which makes up

252
00:15:03,960 --> 00:15:07,960
Speaker 1: your beam bridge deck. Right, Um, you're gonna see that

253
00:15:08,000 --> 00:15:10,360
Speaker 1: it bows, and what you're seeing is that on the

254
00:15:10,400 --> 00:15:16,080
Speaker 1: top it's being compressed. On the bottom, it's being um tensed, right. Um.

255
00:15:16,200 --> 00:15:18,720
Speaker 1: And what you've just done is add a load to

256
00:15:19,360 --> 00:15:21,520
Speaker 1: that bridge. And there's two kinds of loads to start

257
00:15:21,520 --> 00:15:24,480
Speaker 1: out with. There's a deadload, which is the weight of

258
00:15:24,560 --> 00:15:27,800
Speaker 1: the bridge and all of its materials combined. And then

259
00:15:27,800 --> 00:15:30,600
Speaker 1: there's a live load, which is say, like the cars

260
00:15:30,640 --> 00:15:32,960
Speaker 1: and the people and the trains and everything that that

261
00:15:33,120 --> 00:15:36,080
Speaker 1: add the extra weight while they're moving across it and everything.

262
00:15:36,320 --> 00:15:38,320
Speaker 1: And as you add this extra load, first of all,

263
00:15:38,400 --> 00:15:41,160
Speaker 1: the bridge is already dealing with its deadload. You's got

264
00:15:41,160 --> 00:15:44,080
Speaker 1: to hold that up. That's job number one for a bridge. Yeah,

265
00:15:44,120 --> 00:15:46,760
Speaker 1: Like if you had a three hundred foot two by

266
00:15:46,760 --> 00:15:49,280
Speaker 1: four and two milk crates it's gonna sag in the

267
00:15:49,280 --> 00:15:51,920
Speaker 1: middle just naturally, right, and it might even break. And

268
00:15:51,960 --> 00:15:54,520
Speaker 1: there have been bridges that have been built that where

269
00:15:54,600 --> 00:15:57,080
Speaker 1: the guy forgot to carry the one or whatever and

270
00:15:57,120 --> 00:15:59,480
Speaker 1: they couldn't stand up under their own weight and they

271
00:15:59,520 --> 00:16:02,160
Speaker 1: collapse from their own weight. They collapse from the deadload.

272
00:16:02,520 --> 00:16:04,840
Speaker 1: So job number one of the bridge is to support

273
00:16:04,880 --> 00:16:09,040
Speaker 1: its own weight. Job number one point one is to

274
00:16:09,800 --> 00:16:13,040
Speaker 1: support all of the liveload the traffic that goes across

275
00:16:13,080 --> 00:16:16,000
Speaker 1: it as well. That's right. Uh. And the two ways

276
00:16:16,080 --> 00:16:18,720
Speaker 1: that you're going to do this to counteract tension and

277
00:16:18,720 --> 00:16:24,040
Speaker 1: compression are dissipation and transference force or transferring the force.

278
00:16:24,120 --> 00:16:28,080
Speaker 1: So with dissipation you spread out that force equally, you

279
00:16:28,120 --> 00:16:32,120
Speaker 1: spread out over a wide area, and with transferring um

280
00:16:32,200 --> 00:16:35,960
Speaker 1: you move the area of weakness to an area of strength, right,

281
00:16:36,000 --> 00:16:40,120
Speaker 1: which pretty simple. Yeah, they're kind of tough to distinguish sometimes, Yeah,

282
00:16:40,440 --> 00:16:42,920
Speaker 1: you know what I mean. But for example, like the

283
00:16:42,960 --> 00:16:46,440
Speaker 1: best example of dissipation is the arch, which we'll talk

284
00:16:46,480 --> 00:16:50,240
Speaker 1: about how that works in a second. Um. But suspension

285
00:16:50,280 --> 00:16:56,040
Speaker 1: bridges are best at transferring the um the tension and

286
00:16:56,280 --> 00:16:59,760
Speaker 1: compression forces. That's right. So if you're if you're talking

287
00:16:59,760 --> 00:17:02,400
Speaker 1: about to beam bridge that most basic kind. Uh. The

288
00:17:02,400 --> 00:17:04,399
Speaker 1: other thing they're gonna do to make it stronger, of course,

289
00:17:04,480 --> 00:17:06,840
Speaker 1: is use back in the old days, use wood than

290
00:17:06,920 --> 00:17:12,159
Speaker 1: later iron and then steel, maybe some concrete mixed in um.

291
00:17:12,200 --> 00:17:15,240
Speaker 1: But the size of the beam is gonna be really important.

292
00:17:15,280 --> 00:17:18,480
Speaker 1: Like the height of the beam is important because the

293
00:17:18,480 --> 00:17:20,840
Speaker 1: the top is gonna experience stress, the bottom is gonna

294
00:17:20,840 --> 00:17:23,760
Speaker 1: experience stress in the middle not as much. So a

295
00:17:23,800 --> 00:17:27,160
Speaker 1: good I beam, a good tall ibam is what you want. Yeah,

296
00:17:27,200 --> 00:17:29,400
Speaker 1: and I didn't realize that. That's why I beams are made.

297
00:17:29,600 --> 00:17:34,479
Speaker 1: Like I beam, the center of the deck or the

298
00:17:34,520 --> 00:17:37,320
Speaker 1: beam or whatever, any kind of beam is going to

299
00:17:37,359 --> 00:17:40,560
Speaker 1: experience the least amount of compression or tension. It's really

300
00:17:40,640 --> 00:17:43,040
Speaker 1: the top or the bottom. So you don't have to

301
00:17:43,080 --> 00:17:45,439
Speaker 1: put quite as much material into the center of the

302
00:17:45,480 --> 00:17:47,879
Speaker 1: beam as you do the top and the bottom to

303
00:17:48,040 --> 00:17:51,760
Speaker 1: prevent buckling and snapping. That's right. So with the beam bridge,

304
00:17:51,800 --> 00:17:54,760
Speaker 1: you're gonna add what's called a truss uh to make

305
00:17:54,800 --> 00:17:57,240
Speaker 1: it stronger. This uh, we'll talk about trust is more

306
00:17:57,280 --> 00:18:02,840
Speaker 1: but it's basically reriangulated strength. And you'll see a trust

307
00:18:02,880 --> 00:18:06,960
Speaker 1: if you've ever seen like a a train bridge like

308
00:18:07,240 --> 00:18:11,320
Speaker 1: you see a trust on top or like in areas

309
00:18:11,320 --> 00:18:14,560
Speaker 1: where they get a lot of snow, roof supports will

310
00:18:14,640 --> 00:18:17,800
Speaker 1: frequently be trusses. Yeah, and that's a three trust on

311
00:18:17,800 --> 00:18:20,639
Speaker 1: top we already said. And if it's underneath then it

312
00:18:20,800 --> 00:18:24,720
Speaker 1: is uh the deck trust and you can have both,

313
00:18:24,760 --> 00:18:27,600
Speaker 1: but usually, like with the railroads, you'll see like that

314
00:18:27,680 --> 00:18:30,879
Speaker 1: top trust not the same as a trestle. That's different.

315
00:18:31,560 --> 00:18:36,040
Speaker 1: That's like like a roller coaster, you know. So after

316
00:18:36,040 --> 00:18:59,520
Speaker 1: this break, why don't we talk more about trust bridges? Nice? So,

317
00:19:00,280 --> 00:19:03,320
Speaker 1: no joke. Trusses are one of my favorite things now,

318
00:19:03,600 --> 00:19:06,399
Speaker 1: it's pretty neat. After doing some research into him, I'm like,

319
00:19:06,640 --> 00:19:13,680
Speaker 1: I love trust. Yeah, and it's because they're so elegant

320
00:19:13,760 --> 00:19:17,880
Speaker 1: and simple. They're elegantly simple basically. So, um, I saw

321
00:19:17,960 --> 00:19:22,480
Speaker 1: this really great explanation where it was on Make magazine

322
00:19:22,600 --> 00:19:25,320
Speaker 1: and I think it was called like ask Make, how

323
00:19:25,359 --> 00:19:29,360
Speaker 1: do trust? His work? Pretty straightforward, um, and it basically

324
00:19:29,400 --> 00:19:34,080
Speaker 1: had like a really get a great graphic of taking

325
00:19:34,640 --> 00:19:37,879
Speaker 1: using popsicle sticks. Right, Let's say you make a square

326
00:19:37,880 --> 00:19:41,159
Speaker 1: out of popsicle sticks, and you joined the popsicle sticks

327
00:19:41,160 --> 00:19:43,560
Speaker 1: together at the corners where the ends all meet. Ye,

328
00:19:43,680 --> 00:19:48,360
Speaker 1: little Elmer's paste. Maybe makes sense. It seems pretty supportive, right,

329
00:19:48,440 --> 00:19:51,320
Speaker 1: But when you pressed down on any one of those joints,

330
00:19:51,400 --> 00:19:54,840
Speaker 1: which is where the load's going to be centered or

331
00:19:54,880 --> 00:20:00,920
Speaker 1: distributed most remember the ends the square shift to the side,

332
00:20:00,920 --> 00:20:02,760
Speaker 1: and all of a sudden you have a rhombus. Well,

333
00:20:02,840 --> 00:20:06,840
Speaker 1: rambus is inherently less structurally sound than square, which is

334
00:20:06,840 --> 00:20:11,160
Speaker 1: why you very rarely see rambus as in architecture. Right,

335
00:20:11,520 --> 00:20:13,920
Speaker 1: with a triangle, when you press down at any one

336
00:20:13,920 --> 00:20:19,720
Speaker 1: of the joints, it distributes that compression or tension directly

337
00:20:19,720 --> 00:20:24,080
Speaker 1: through the center of the beam, so the triangle stays

338
00:20:24,160 --> 00:20:27,240
Speaker 1: totally rigid. And when you add, the more triangles you add,

339
00:20:27,240 --> 00:20:30,320
Speaker 1: the more support you have, So they're like basically like

340
00:20:31,080 --> 00:20:34,840
Speaker 1: as far as the shape goes, the superconductor of transferring

341
00:20:34,960 --> 00:20:39,560
Speaker 1: or distributing compression or tension. Yeah, that's a good way

342
00:20:39,560 --> 00:20:41,080
Speaker 1: to put it. And that's why when you see that

343
00:20:41,080 --> 00:20:44,200
Speaker 1: that train tress alone that has that trust on topics,

344
00:20:44,680 --> 00:20:49,639
Speaker 1: got all those beautiful diagonal uh pieces of metal. And

345
00:20:49,680 --> 00:20:51,520
Speaker 1: it's not just for for looks, even though it is

346
00:20:51,520 --> 00:20:54,159
Speaker 1: cool looking. No. One of the other great things about

347
00:20:54,200 --> 00:20:57,000
Speaker 1: a trust is that there you know, it's like just

348
00:20:57,119 --> 00:21:01,200
Speaker 1: a three steel beams or three whatever aluminium beams. They're

349
00:21:01,240 --> 00:21:05,840
Speaker 1: just three pieces of metal usually fixed together. And that's

350
00:21:05,920 --> 00:21:08,639
Speaker 1: that's the other key that I left out. They have

351
00:21:08,760 --> 00:21:14,280
Speaker 1: to be connected at the ends equally distributed from each end. Right, So,

352
00:21:14,359 --> 00:21:16,879
Speaker 1: let's say you you drill a hole to to rivet

353
00:21:16,960 --> 00:21:19,720
Speaker 1: one side of the trust to another, or one end

354
00:21:19,760 --> 00:21:23,080
Speaker 1: of the trust to another end, the the other end

355
00:21:23,119 --> 00:21:26,480
Speaker 1: has to be equally far away. Do you see what

356
00:21:26,560 --> 00:21:28,600
Speaker 1: I'm saying. Yeah, yeah, okay, they wouldn't just be like

357
00:21:28,880 --> 00:21:31,280
Speaker 1: just drill that other one wherever. So anyway you have

358
00:21:31,359 --> 00:21:35,720
Speaker 1: to the place where the trust sides join together has

359
00:21:35,720 --> 00:21:38,080
Speaker 1: to be on the ends. And then but one of

360
00:21:38,080 --> 00:21:40,919
Speaker 1: the things that it allows for is for wind to

361
00:21:40,960 --> 00:21:44,520
Speaker 1: blow through it easily. That's a huge point about trusses.

362
00:21:45,080 --> 00:21:50,080
Speaker 1: They're not solid in that they don't they don't put

363
00:21:50,160 --> 00:21:52,240
Speaker 1: up a lot of resistance to when they allow it

364
00:21:52,280 --> 00:21:54,320
Speaker 1: to flow through, which is really kind of what you want.

365
00:21:54,440 --> 00:21:57,760
Speaker 1: We'll see when you're building bridges. Yeah, I think even

366
00:21:57,800 --> 00:22:00,480
Speaker 1: the covered bridges have is more of a that's type

367
00:22:00,520 --> 00:22:04,560
Speaker 1: thing on the sides. Right. Yes, it's not solid, is it.

368
00:22:04,600 --> 00:22:08,080
Speaker 1: That'd be dumb a covered bridge. Yeah. I thought the

369
00:22:08,080 --> 00:22:10,560
Speaker 1: walls were usually like a lattice so wind could pass through.

370
00:22:10,680 --> 00:22:13,480
Speaker 1: Now and they had a than a roof and like

371
00:22:14,040 --> 00:22:17,760
Speaker 1: a lattice e side is there, right, Yeah, maybe there's

372
00:22:17,760 --> 00:22:21,320
Speaker 1: all kinds. I think those are just to keep the

373
00:22:21,440 --> 00:22:25,200
Speaker 1: rain off. Oh yeah, that's what you said earlier and

374
00:22:25,320 --> 00:22:31,080
Speaker 1: keep shooting down there. Yeah. But anyway, trust is rock,

375
00:22:31,200 --> 00:22:33,680
Speaker 1: I guess, is what I'm trying to say. Yes, there's

376
00:22:33,680 --> 00:22:37,720
Speaker 1: your T shirt. Trusses rock. So are we at arches?

377
00:22:39,440 --> 00:22:42,520
Speaker 1: Do we say that they frequently used trusses to support

378
00:22:42,880 --> 00:22:48,280
Speaker 1: beam bridges? Yeah? Arches. Now, when we say a bridge

379
00:22:48,359 --> 00:22:52,520
Speaker 1: is an arch bridge, the deck is not some big

380
00:22:52,600 --> 00:22:55,560
Speaker 1: hill that you drive over. The deck is flat the

381
00:22:55,640 --> 00:23:01,240
Speaker 1: arches underneath, uh right yeah. And you can have a

382
00:23:01,280 --> 00:23:04,080
Speaker 1: single arch if your span isn't along, or you can

383
00:23:04,119 --> 00:23:06,760
Speaker 1: have a big one with like six or eight arches.

384
00:23:07,480 --> 00:23:10,360
Speaker 1: Although I've seen I think there are like short arch

385
00:23:10,440 --> 00:23:13,760
Speaker 1: bridges that actually do go up and down, you know,

386
00:23:13,760 --> 00:23:17,480
Speaker 1: like if there's natural arch bridges, like rock formations are

387
00:23:17,560 --> 00:23:19,960
Speaker 1: like that and that's why they're still standing. There's um

388
00:23:20,000 --> 00:23:25,200
Speaker 1: there's there's a bridge that forms like a perfect circle.

389
00:23:26,160 --> 00:23:28,760
Speaker 1: So like when when you see it reflected in the water,

390
00:23:28,840 --> 00:23:33,480
Speaker 1: it just looks like a circle. Arch bridges are pretty

391
00:23:33,480 --> 00:23:36,600
Speaker 1: cool too. There are no trusses, but they're beautiful in

392
00:23:36,600 --> 00:23:39,919
Speaker 1: their own way. That's true. Uh So the arches obviously

393
00:23:40,080 --> 00:23:43,040
Speaker 1: semi circular. Um. And like you said, if it meets

394
00:23:43,040 --> 00:23:47,439
Speaker 1: the water and reflects nicely, fully circular, fully circular. Uh

395
00:23:47,480 --> 00:23:51,119
Speaker 1: And the entire form is gonna divert weight onto what

396
00:23:51,160 --> 00:23:54,960
Speaker 1: are called abutments. And this is what takes on the pressure.

397
00:23:55,000 --> 00:23:57,840
Speaker 1: It's like, I mean, if it's just a single arch,

398
00:23:57,920 --> 00:23:59,720
Speaker 1: those abutments are probably going to be part of the

399
00:23:59,720 --> 00:24:04,119
Speaker 1: earth on one side or the other. Yeah. Um. And

400
00:24:04,200 --> 00:24:07,119
Speaker 1: the whole point of an abutment is when you press

401
00:24:07,160 --> 00:24:10,159
Speaker 1: down in an arch, or when you know, gravity pushes

402
00:24:10,200 --> 00:24:14,880
Speaker 1: down on it or it's compressed, that force goes downward

403
00:24:15,000 --> 00:24:17,080
Speaker 1: and it makes the sides of the arch go out.

404
00:24:17,760 --> 00:24:22,280
Speaker 1: Those abutments press inward, so that the force of compression

405
00:24:22,600 --> 00:24:26,600
Speaker 1: just goes straight down through the arch circle the semicircle

406
00:24:26,880 --> 00:24:29,920
Speaker 1: and into the earth or into the ground or whatever. Yeah.

407
00:24:29,920 --> 00:24:32,800
Speaker 1: And and it's the arch. The what I thought was interesting,

408
00:24:32,800 --> 00:24:35,520
Speaker 1: it's really all about fighting that compression. There isn't a

409
00:24:35,560 --> 00:24:38,960
Speaker 1: lot of tension that comes into play with an arch bridge.

410
00:24:39,000 --> 00:24:42,240
Speaker 1: I think the tension is grows more and more possible

411
00:24:42,640 --> 00:24:48,320
Speaker 1: when the degree of the arc or arch grows. Okay, yeah,

412
00:24:48,680 --> 00:24:50,679
Speaker 1: so that could come into play. It can, but for

413
00:24:50,720 --> 00:24:53,080
Speaker 1: the most part, when you're building an arch, you have

414
00:24:53,200 --> 00:24:56,800
Speaker 1: to worry about compression more than tension, gotcha. So there's

415
00:24:56,840 --> 00:25:01,600
Speaker 1: a stylistically and artistically design wise. They're all kinds of arches.

416
00:25:01,960 --> 00:25:06,639
Speaker 1: Baroque arches, Renaissance arches, Roman arches. They were the Romans built,

417
00:25:07,040 --> 00:25:10,880
Speaker 1: you know, arch bridges that are still standing today. Um,

418
00:25:10,920 --> 00:25:13,639
Speaker 1: have you been to Rome? Yeah? Man, it's just like

419
00:25:13,680 --> 00:25:15,919
Speaker 1: you're walking along and all of a sudden you look

420
00:25:15,960 --> 00:25:18,040
Speaker 1: to your leaps and there's like a two thousand year

421
00:25:18,040 --> 00:25:23,160
Speaker 1: old aqueduct, you know, hundred year old arch just sitting there. Yeah.

422
00:25:23,200 --> 00:25:25,240
Speaker 1: I remember the first time I went to Europe coming

423
00:25:25,240 --> 00:25:28,439
Speaker 1: back and being sort of like bummed out, you know,

424
00:25:28,480 --> 00:25:31,760
Speaker 1: because we're walking along and then there's Burger king. You know,

425
00:25:32,680 --> 00:25:37,080
Speaker 1: this is two hundred years old. She go to Rome.

426
00:25:37,520 --> 00:25:39,240
Speaker 1: I know, my house is like eighty years old, and

427
00:25:39,280 --> 00:25:45,040
Speaker 1: it seems super old. Nothing by Romans standards. No, but

428
00:25:45,119 --> 00:25:48,760
Speaker 1: you know, a little drafty in those thousand year old apartments. Yeah,

429
00:25:48,760 --> 00:25:51,080
Speaker 1: but it's so neat though, because I mean like there's

430
00:25:51,160 --> 00:25:55,760
Speaker 1: so much old surviving stuff that not all of it's

431
00:25:55,800 --> 00:25:58,120
Speaker 1: even meant to be preserved. Some of it's just like

432
00:25:59,000 --> 00:26:01,480
Speaker 1: just there. It's not like a part of a park

433
00:26:01,600 --> 00:26:05,359
Speaker 1: or an historic exhibit. It's just part of the city. Yeah,

434
00:26:05,400 --> 00:26:09,919
Speaker 1: you know, Yeah, I've heard other tourists complaining about how

435
00:26:09,960 --> 00:26:13,360
Speaker 1: dirty Rome is, and I'm always just like, come on,

436
00:26:13,520 --> 00:26:16,439
Speaker 1: it's like focusing on the wrong part. It's been around

437
00:26:16,440 --> 00:26:21,600
Speaker 1: for a long time. Um yeah. And also yeah, don't

438
00:26:21,600 --> 00:26:25,200
Speaker 1: be stupid and just look around you like they're complaining

439
00:26:25,200 --> 00:26:26,840
Speaker 1: in front of a two thousand year old fountain. I

440
00:26:26,880 --> 00:26:30,840
Speaker 1: didn't notice that was particularly dirty. I mean, it wasn't

441
00:26:30,920 --> 00:26:33,520
Speaker 1: any more dirty than like New York or anything any

442
00:26:33,560 --> 00:26:37,080
Speaker 1: other big city. But the thing with the arch though

443
00:26:37,520 --> 00:26:40,720
Speaker 1: very stable once you get it built. But the building

444
00:26:40,760 --> 00:26:45,960
Speaker 1: process it's tricky because until you connect those two ends, um,

445
00:26:46,000 --> 00:26:48,280
Speaker 1: that's what gives it its strength. So until that happens,

446
00:26:48,560 --> 00:26:51,000
Speaker 1: it's a little dicey. Yeah. Oh yeah, I had some

447
00:26:51,040 --> 00:26:53,760
Speaker 1: scaffolding come on time. Yeah. And they used to build

448
00:26:53,760 --> 00:26:57,600
Speaker 1: wood scalf scaffolds and supports to hold the thing and

449
00:26:57,600 --> 00:27:00,879
Speaker 1: then you just would build it in. Um. Now they

450
00:27:00,960 --> 00:27:05,520
Speaker 1: use suspension cables like I think the biggest arch bridge

451
00:27:05,920 --> 00:27:09,440
Speaker 1: on the planet is West Virginia's New River Gorge Bridge,

452
00:27:09,600 --> 00:27:12,080
Speaker 1: and that thing is unbelievable. It really is. And what's

453
00:27:12,119 --> 00:27:15,120
Speaker 1: cool is when you look at it, UM, it just

454
00:27:15,600 --> 00:27:18,439
Speaker 1: it uses the cliff walls or the walls of the

455
00:27:18,520 --> 00:27:22,840
Speaker 1: gorge as the abutments. Beautiful stuff, super strong. And that's

456
00:27:22,840 --> 00:27:26,480
Speaker 1: where we're going to talk about that in our base dumping.

457
00:27:26,520 --> 00:27:29,600
Speaker 1: I know. That's the fact that ties these two podcasts together.

458
00:27:29,600 --> 00:27:32,680
Speaker 1: It's where they have Bridge Day talk about elegantly simple.

459
00:27:34,320 --> 00:27:38,040
Speaker 1: So suspension bridges, for my money, are where it's at.

460
00:27:38,680 --> 00:27:43,680
Speaker 1: I think they deserve their own UM episode. Oh yeah, pretty,

461
00:27:43,720 --> 00:27:47,439
Speaker 1: I'm pretty much they're they're that complex. Like this is

462
00:27:47,520 --> 00:27:51,800
Speaker 1: just the briefest overview of bridges in general, but especially

463
00:27:51,800 --> 00:27:54,920
Speaker 1: with suspension bridges. It feels like there's just so much

464
00:27:54,960 --> 00:27:57,359
Speaker 1: going on with those things. Yeah, I agree. I mean,

465
00:27:57,440 --> 00:28:00,119
Speaker 1: Kim Burns did like an eight hour long documentary the

466
00:28:00,160 --> 00:28:03,920
Speaker 1: Brooklyn Bridge alone. Yeah, that's true. He's a deep diver.

467
00:28:05,240 --> 00:28:08,560
Speaker 1: We're over of you guys with a giant helmet to

468
00:28:08,600 --> 00:28:12,119
Speaker 1: go over his giant haircut, because a pretty big hair

469
00:28:12,240 --> 00:28:16,639
Speaker 1: doan UM. All right, So suspension bridges we mentioned, of course,

470
00:28:16,840 --> 00:28:19,600
Speaker 1: Golden Gate Bridge and the Brooklyn Bridge. This is when

471
00:28:19,880 --> 00:28:23,920
Speaker 1: you have your deck, your roadway is suspended by cables

472
00:28:25,359 --> 00:28:28,879
Speaker 1: between can be a number of them, but uh to

473
00:28:29,320 --> 00:28:32,320
Speaker 1: at least two tall towers that are supporting all of

474
00:28:32,359 --> 00:28:36,760
Speaker 1: this weight and compression is pushing down, traveling up through

475
00:28:36,800 --> 00:28:40,400
Speaker 1: those cables and transferring all that compression through all those

476
00:28:40,440 --> 00:28:42,960
Speaker 1: lovely cables. Right. So, I mean another way to look

477
00:28:43,000 --> 00:28:45,400
Speaker 1: at it is exactly what it sounds like. It's the

478
00:28:45,480 --> 00:28:49,120
Speaker 1: bridge is suspended from cables, right, But if you really

479
00:28:49,160 --> 00:28:52,560
Speaker 1: start looking into what it's doing, it's not just holding

480
00:28:52,560 --> 00:28:55,400
Speaker 1: these things up. What's what's going on is there's a

481
00:28:55,440 --> 00:28:59,760
Speaker 1: transfer of that natural compression of the deck up through

482
00:28:59,800 --> 00:29:03,000
Speaker 1: the lines, up through the cables up down up to

483
00:29:03,080 --> 00:29:05,440
Speaker 1: the towers, which, like you said, send them down to

484
00:29:05,480 --> 00:29:09,160
Speaker 1: the earth. Right, So the towers that hold the bridge

485
00:29:09,200 --> 00:29:14,840
Speaker 1: up are at the same time distributing or dissipating the

486
00:29:14,920 --> 00:29:17,600
Speaker 1: forces of compression that are trying to pull the bridge

487
00:29:17,640 --> 00:29:21,000
Speaker 1: down into the water below it. Yes, and the tension

488
00:29:21,080 --> 00:29:23,800
Speaker 1: you also have to deal with as well, and apparently

489
00:29:24,000 --> 00:29:27,240
Speaker 1: you deal with that using another part of the structure

490
00:29:27,240 --> 00:29:31,880
Speaker 1: of suspension bridges, which are called anchorages. Yeah. Now, that's

491
00:29:31,920 --> 00:29:35,440
Speaker 1: just what the towers connected to at the base right now. No,

492
00:29:35,560 --> 00:29:39,800
Speaker 1: huh so it's like um anchorages is like the abutment essentially. Yes,

493
00:29:40,680 --> 00:29:44,280
Speaker 1: they're they're like a suspension bridges abutments. Whereas as you

494
00:29:44,320 --> 00:29:46,920
Speaker 1: get closer to the middle of the bridges, that's where

495
00:29:46,920 --> 00:29:49,680
Speaker 1: the towers are. But on the very ends, like say

496
00:29:49,680 --> 00:29:52,560
Speaker 1: where the roadway hits the bridge, you're gonna have a

497
00:29:52,600 --> 00:29:56,800
Speaker 1: massive piece of rock or massive piece of concrete, and

498
00:29:56,880 --> 00:30:01,959
Speaker 1: those are the anchorages. And you have horizontal cables that

499
00:30:02,040 --> 00:30:05,800
Speaker 1: distribute the compression from the bottom of the bridge to

500
00:30:06,360 --> 00:30:11,320
Speaker 1: um the anchorages and those those transfer those into the earth. Yeah.

501
00:30:11,360 --> 00:30:13,440
Speaker 1: And you might also, depending on the size of your

502
00:30:13,480 --> 00:30:17,600
Speaker 1: suspension bridge, have to have that below deck truss as

503
00:30:17,600 --> 00:30:20,800
Speaker 1: well to help stiffen the deck um. And you know,

504
00:30:20,840 --> 00:30:23,880
Speaker 1: if you have a four thousand foot bridge, you're gonna

505
00:30:23,920 --> 00:30:27,920
Speaker 1: have all all kinds of trusses and decks and cables.

506
00:30:27,960 --> 00:30:30,240
Speaker 1: And I think I finally figured out what it is

507
00:30:30,240 --> 00:30:34,200
Speaker 1: about bridges that I love is that the the arc,

508
00:30:34,600 --> 00:30:38,760
Speaker 1: the structural design that it needs to be strong, also

509
00:30:38,880 --> 00:30:41,720
Speaker 1: happens to be beautiful. Yeah, you know what I mean,

510
00:30:42,160 --> 00:30:44,640
Speaker 1: Like the way the cables are arranged. It's not like

511
00:30:44,640 --> 00:30:46,880
Speaker 1: they're like, oh, this looks great. It's like, well it

512
00:30:46,920 --> 00:30:49,440
Speaker 1: has to be like this, but it also happens to

513
00:30:49,480 --> 00:30:54,600
Speaker 1: be very striking, like Grace Jones, you know what I mean? Yeah,

514
00:30:55,240 --> 00:31:00,360
Speaker 1: absolutely so. Um So, suspension bridges are your favorite, huh.

515
00:31:00,960 --> 00:31:02,760
Speaker 1: I like them because they have so much going on.

516
00:31:03,120 --> 00:31:06,080
Speaker 1: I like trust is because they're so elegantly simple and

517
00:31:06,120 --> 00:31:08,560
Speaker 1: they're just tough as nails. There's a bridge for everyone.

518
00:31:08,600 --> 00:31:11,760
Speaker 1: I think there really is. Um the cable stayed bridge,

519
00:31:12,360 --> 00:31:15,160
Speaker 1: and we should say that suspension bridges. When you think

520
00:31:15,160 --> 00:31:18,040
Speaker 1: of a suspension bridge, probably probably think of the Golden

521
00:31:18,040 --> 00:31:20,680
Speaker 1: gate bridge or something like that. Right, Just a classic

522
00:31:20,760 --> 00:31:26,640
Speaker 1: suspension bridge, two towers to um anchorages, lots of suspension cables.

523
00:31:26,680 --> 00:31:29,600
Speaker 1: It's the suspension bridge and you think, well, then they're

524
00:31:29,600 --> 00:31:34,320
Speaker 1: probably pretty new. Wrong. Suspension bridges have been found in

525
00:31:34,600 --> 00:31:38,320
Speaker 1: various forms for hundreds of years at least, and apparently

526
00:31:38,520 --> 00:31:43,959
Speaker 1: the Inca were um masters at building rope suspension bridges

527
00:31:43,960 --> 00:31:47,680
Speaker 1: out of woven grass. Crazy man, Yeah, fifteen hundreds they

528
00:31:47,760 --> 00:31:51,680
Speaker 1: discovered the Spanish concreteadores stumbled upon these were like, what

529
00:31:51,800 --> 00:31:54,880
Speaker 1: in the world is going on here? Because the smart

530
00:31:54,960 --> 00:31:57,840
Speaker 1: Europeans didn't figure this out for another like few hundred

531
00:31:57,920 --> 00:32:01,400
Speaker 1: years after that. That's right. Um, the inc Is still

532
00:32:01,440 --> 00:32:04,560
Speaker 1: have one of these bridges intact. It it spans ninety

533
00:32:04,640 --> 00:32:08,200
Speaker 1: ft um and they remake it every year as part

534
00:32:08,200 --> 00:32:11,680
Speaker 1: of a three day festival. Really nice, which is why

535
00:32:11,680 --> 00:32:15,440
Speaker 1: it's still intact because the grass woven grass rope bridge

536
00:32:15,760 --> 00:32:19,000
Speaker 1: didn't last all that long necessarily even though why when

537
00:32:19,000 --> 00:32:22,680
Speaker 1: it's fresh and new, it's strong as an expiration date

538
00:32:22,960 --> 00:32:26,320
Speaker 1: what you're saying. But apparently, as we'll learn, all bridges

539
00:32:26,400 --> 00:32:29,200
Speaker 1: have an expiration date. All right, Well we'll take a

540
00:32:29,240 --> 00:32:32,040
Speaker 1: break then with that tease and talk about the cable

541
00:32:32,080 --> 00:32:34,920
Speaker 1: stayed bridge and then um, how you might die on

542
00:32:34,960 --> 00:32:57,120
Speaker 1: a bridge one day. Alright, so we're onto your favorite,

543
00:32:57,120 --> 00:33:02,040
Speaker 1: my friend, the super sleek, modern looking cable stayed bridge,

544
00:33:02,080 --> 00:33:07,000
Speaker 1: which is actually actually actually has been around since like

545
00:33:07,040 --> 00:33:10,640
Speaker 1: World War two. Yeah, but the idea which is modern.

546
00:33:10,840 --> 00:33:15,640
Speaker 1: The idea came from a dude named um Fast Ranchica

547
00:33:15,760 --> 00:33:18,920
Speaker 1: Man and he was a contemporary of Kepler and brahi

548
00:33:19,520 --> 00:33:23,440
Speaker 1: Um and he basically came up with the first design

549
00:33:23,600 --> 00:33:26,520
Speaker 1: for a cable stayed bridge back in the sixteenth century.

550
00:33:26,680 --> 00:33:28,520
Speaker 1: So what's what's the nuts and bolts of this thing.

551
00:33:29,360 --> 00:33:34,080
Speaker 1: So basically it is a rather than two towers like

552
00:33:34,120 --> 00:33:37,560
Speaker 1: a suspension bridge uses, a cable state bridge uses one tower.

553
00:33:37,800 --> 00:33:40,320
Speaker 1: Well not always um, there's plenty of them that have

554
00:33:40,360 --> 00:33:44,200
Speaker 1: more than one, but okay, but for a particular span

555
00:33:44,280 --> 00:33:48,480
Speaker 1: of bridge, there's one tower supporting that one span, right, UM.

556
00:33:48,600 --> 00:33:51,680
Speaker 1: So it's basically you can't use it for as long

557
00:33:51,720 --> 00:33:54,480
Speaker 1: of a span as a suspension bridge. But if you

558
00:33:54,520 --> 00:33:56,840
Speaker 1: have a slightly shorter span and you don't want to

559
00:33:56,880 --> 00:33:59,120
Speaker 1: spend quite as much money and you don't want as

560
00:33:59,160 --> 00:34:01,640
Speaker 1: many wires up there and everything, you can go with

561
00:34:01,720 --> 00:34:05,280
Speaker 1: the cable state bridge. So you have one usually one

562
00:34:05,600 --> 00:34:09,320
Speaker 1: UM tower holding up all the cables, and the cables

563
00:34:09,320 --> 00:34:12,840
Speaker 1: can either all connect to one point, which is called

564
00:34:13,080 --> 00:34:19,080
Speaker 1: a UM radio pattern. Right, So it's like all these

565
00:34:19,120 --> 00:34:23,160
Speaker 1: different cables are connecting on the bridge deck at different points,

566
00:34:23,200 --> 00:34:25,759
Speaker 1: but they're all connecting at about a single point on

567
00:34:25,880 --> 00:34:29,919
Speaker 1: the tower. Again architecturally lovely, very neat looking. And then

568
00:34:30,000 --> 00:34:32,600
Speaker 1: another way that you can do it is UM in

569
00:34:32,640 --> 00:34:35,560
Speaker 1: a parallel pattern. So they're connected at different points on

570
00:34:35,600 --> 00:34:38,960
Speaker 1: the deck and they connect at different points on the tower.

571
00:34:39,560 --> 00:34:43,759
Speaker 1: And that's the case with the Erasmus Bridge, which I

572
00:34:43,800 --> 00:34:46,480
Speaker 1: think is the most beautiful bridge in the world in Holland.

573
00:34:46,800 --> 00:34:49,080
Speaker 1: Well that doesn't surprise me. I mean, look at that thing.

574
00:34:49,200 --> 00:34:53,600
Speaker 1: Look at that pal Oh yeah, it's something else. Yeah,

575
00:34:53,840 --> 00:34:56,800
Speaker 1: I wish you guys could see this. Look. It doesn't

576
00:34:56,800 --> 00:35:02,120
Speaker 1: look like very Dutch though, No, it looks very Um

577
00:35:02,160 --> 00:35:06,279
Speaker 1: it's like the New Holland. I guess, yeah, new Amsterdam.

578
00:35:06,320 --> 00:35:09,040
Speaker 1: I'm just picturing like Holland. I think of uh, you know,

579
00:35:09,239 --> 00:35:13,200
Speaker 1: wooden windmills and like two lips and stuff like that. Ye. Sure, yeah,

580
00:35:13,239 --> 00:35:15,120
Speaker 1: this is modern hauland for it looks like something that

581
00:35:15,120 --> 00:35:17,919
Speaker 1: would be in like Sydney, Australia. Well, they have great

582
00:35:17,920 --> 00:35:22,080
Speaker 1: bridge to they do. Maybe that's what I'm thinking, Um,

583
00:35:22,280 --> 00:35:24,080
Speaker 1: living bridge, Well, you are you done with those? Well

584
00:35:24,239 --> 00:35:26,640
Speaker 1: I was gonna say another design for cable state bridge

585
00:35:26,840 --> 00:35:32,520
Speaker 1: looks a lot like a sailboat, with the tower standing

586
00:35:32,560 --> 00:35:35,160
Speaker 1: straight up and then on each side cables going down

587
00:35:35,200 --> 00:35:37,200
Speaker 1: at a diagonal from it to make it look like

588
00:35:37,400 --> 00:35:41,520
Speaker 1: a sailboat, sail and masked and again for structural integrity

589
00:35:41,520 --> 00:35:47,719
Speaker 1: more than anything, right, um living bridges sure, Uh, well,

590
00:35:47,760 --> 00:35:50,879
Speaker 1: I guess we should say cable state bridges are uh

591
00:35:50,920 --> 00:35:53,040
Speaker 1: they can't be as long as suspension bridges, but they

592
00:35:53,040 --> 00:35:56,239
Speaker 1: can be pretty long. Yeah, like have to close to

593
00:35:56,320 --> 00:35:58,319
Speaker 1: three thousand feet. But that's what I'm saying, Like, if

594
00:35:58,320 --> 00:36:01,480
Speaker 1: you have a shorter span and you don't want to

595
00:36:01,560 --> 00:36:04,080
Speaker 1: use as many materials and hints, you spend as much

596
00:36:04,080 --> 00:36:06,520
Speaker 1: money at cable State bridge is a great alternative. Yeah.

597
00:36:06,520 --> 00:36:11,360
Speaker 1: I wonder when cities, Uh, I wonder what the considerations are, um,

598
00:36:11,440 --> 00:36:14,480
Speaker 1: like money, what you I would guess money first and

599
00:36:14,480 --> 00:36:18,400
Speaker 1: foremost money, what you probably is best for the land.

600
00:36:18,520 --> 00:36:22,120
Speaker 1: And but I also bet that that architecture comes into play,

601
00:36:22,200 --> 00:36:24,680
Speaker 1: like how it looks in the city escape, don't you think,

602
00:36:25,880 --> 00:36:28,480
Speaker 1: Like usually a city will have some sort of well

603
00:36:28,520 --> 00:36:33,759
Speaker 1: accept several designs, competing designs, and then probably well like

604
00:36:33,800 --> 00:36:36,600
Speaker 1: in Atlanta's case with the seventeenth street bridge, goes with

605
00:36:36,640 --> 00:36:39,279
Speaker 1: the cheapest one and then half of it falls down

606
00:36:39,280 --> 00:36:41,640
Speaker 1: on the traffic later, like a couple of years later.

607
00:36:41,800 --> 00:36:46,520
Speaker 1: Did that happen? Yeah? Uh when um like to two

608
00:36:46,600 --> 00:36:48,719
Speaker 1: years ago? Really yeah, man, it was a big deal.

609
00:36:48,800 --> 00:36:51,279
Speaker 1: Luckily it happened at like four in the morning or

610
00:36:51,320 --> 00:36:53,880
Speaker 1: five in the morning. But like when you're walking on

611
00:36:53,920 --> 00:36:58,400
Speaker 1: the bridge, you know the side stuff one whole side

612
00:36:58,440 --> 00:37:02,440
Speaker 1: fell over onto seventy below, onto the onto the connector

613
00:37:02,520 --> 00:37:05,000
Speaker 1: right below. Yeah, I kind of remember that. Yeah, but

614
00:37:05,040 --> 00:37:07,640
Speaker 1: it's an ugly bridge to begin with. Three million. Dude,

615
00:37:07,640 --> 00:37:09,880
Speaker 1: if you're listening the guy who designed it, I'm sorry,

616
00:37:09,880 --> 00:37:12,920
Speaker 1: I don't mean to insult your work, but I but

617
00:37:13,000 --> 00:37:16,200
Speaker 1: do better. It just the city could have done better,

618
00:37:16,239 --> 00:37:18,759
Speaker 1: I think. But I think what it came down to,

619
00:37:18,880 --> 00:37:21,799
Speaker 1: I'm sure it was. All of these are beautiful, but

620
00:37:22,160 --> 00:37:24,439
Speaker 1: we're just going to spend the money on this one,

621
00:37:24,560 --> 00:37:27,960
Speaker 1: you know, or whoever got the biggest kick back or

622
00:37:27,960 --> 00:37:33,839
Speaker 1: wherever that came from, not to be cynical. Living bridges. Yeah,

623
00:37:33,920 --> 00:37:37,640
Speaker 1: we're talking about that. Um. If you go to northern

624
00:37:37,719 --> 00:37:42,560
Speaker 1: India to the here we go, uh, the Meghalaya region,

625
00:37:42,880 --> 00:37:46,000
Speaker 1: I think that was good. All right, close enough, Um,

626
00:37:46,080 --> 00:37:50,400
Speaker 1: they have something pretty remarkable and they are called living bridges.

627
00:37:50,640 --> 00:37:54,040
Speaker 1: And what they did was it's so rainy there that

628
00:37:54,160 --> 00:37:56,640
Speaker 1: all of their natural bridges were having a hard time

629
00:37:56,800 --> 00:38:00,600
Speaker 1: staying intact because of all the moisture from monsoons. Yeah,

630
00:38:00,640 --> 00:38:02,920
Speaker 1: and that's you know, you can't have a natural bridge

631
00:38:02,960 --> 00:38:05,640
Speaker 1: with that much water. So they said, why don't we

632
00:38:06,360 --> 00:38:11,360
Speaker 1: take these tree roots and grow them out of the

633
00:38:11,400 --> 00:38:15,640
Speaker 1: ground and span a river over the course of years

634
00:38:15,640 --> 00:38:19,080
Speaker 1: and years and years and then basically plant on the

635
00:38:19,120 --> 00:38:22,480
Speaker 1: other side into the ground and this is now a

636
00:38:22,560 --> 00:38:25,720
Speaker 1: natural tree root bridge. Right, it's like giant living bonds.

637
00:38:25,800 --> 00:38:28,239
Speaker 1: I like you're they were training routes to go a

638
00:38:28,280 --> 00:38:31,520
Speaker 1: certain way, and they would take a um, a tree,

639
00:38:31,600 --> 00:38:34,520
Speaker 1: a felled tree, and split it in half and use

640
00:38:34,640 --> 00:38:37,680
Speaker 1: that as the guide. Right, it's like the structure so

641
00:38:37,800 --> 00:38:39,719
Speaker 1: that they were building an arch, but they weren't making

642
00:38:39,760 --> 00:38:42,239
Speaker 1: an arch like sort of a temporary bridge exactly, and

643
00:38:42,239 --> 00:38:44,720
Speaker 1: they let the roots grow along that and like they

644
00:38:44,760 --> 00:38:46,600
Speaker 1: would plan these things out, or they do plan these

645
00:38:46,600 --> 00:38:49,120
Speaker 1: things out over the course of like a decade. And

646
00:38:49,160 --> 00:38:52,640
Speaker 1: I get the impression it's, um, the whole town's responsibilityly,

647
00:38:52,680 --> 00:38:55,359
Speaker 1: some people in the town's responsibility to make sure that

648
00:38:55,440 --> 00:38:57,160
Speaker 1: if you see your route starting to go down in

649
00:38:57,200 --> 00:38:59,319
Speaker 1: the wrong place, you just pluck it up and put

650
00:38:59,360 --> 00:39:02,200
Speaker 1: it back on a fell log that's guiding it across

651
00:39:02,360 --> 00:39:05,800
Speaker 1: the way. Yeah, it's pretty neat, like it requires patients obviously,

652
00:39:05,840 --> 00:39:09,279
Speaker 1: but it also um, I imagine just once a day

653
00:39:09,280 --> 00:39:12,440
Speaker 1: someone walks down and it's like yep, looking good, and

654
00:39:12,480 --> 00:39:15,800
Speaker 1: then just walks away again, pets. The bridge says, keep growing,

655
00:39:15,920 --> 00:39:18,920
Speaker 1: I'll walk across in ten years, buddy. And apparently those

656
00:39:18,960 --> 00:39:21,440
Speaker 1: things can last up to fifty years or the the

657
00:39:21,520 --> 00:39:24,759
Speaker 1: largest one that they have up to a hundred feet,

658
00:39:24,800 --> 00:39:27,799
Speaker 1: which is thirty meters for our friends in India. Um,

659
00:39:27,840 --> 00:39:30,279
Speaker 1: and it can bear the way to fifty people and

660
00:39:30,360 --> 00:39:33,680
Speaker 1: last up to five years, not fifty. That's what I said. Oh,

661
00:39:33,680 --> 00:39:38,880
Speaker 1: I thought you said people, well, it's crazy, like you

662
00:39:38,960 --> 00:39:42,400
Speaker 1: gotta google these things. Yeah, they're very pretty, very pretty.

663
00:39:42,719 --> 00:39:47,040
Speaker 1: It looks very um dark crystally. Oh yeah, totally, you

664
00:39:47,040 --> 00:39:49,759
Speaker 1: know what I mean. But they're not unsettling at all

665
00:39:50,840 --> 00:39:53,520
Speaker 1: like the dark crystal right, which, by the way, if

666
00:39:53,520 --> 00:39:56,160
Speaker 1: you're ever in Atlanta, sometimes people say, Hey, I'm coming

667
00:39:56,160 --> 00:39:59,400
Speaker 1: to Atlanta. What should I do? Uh, go to the

668
00:39:59,440 --> 00:40:03,120
Speaker 1: Center for Popetry Arts and just look at their free exhibit,

669
00:40:03,520 --> 00:40:08,680
Speaker 1: which includes a full size Skexy. It's terrifying. Yeah, they

670
00:40:08,680 --> 00:40:11,279
Speaker 1: have We've talked about this before. They have emmett Utter.

671
00:40:13,280 --> 00:40:16,200
Speaker 1: For me, that was pretty pretty magnificent. It meant a

672
00:40:16,200 --> 00:40:19,600
Speaker 1: lot for Emma Utter to meet you too. They're doing

673
00:40:19,640 --> 00:40:21,600
Speaker 1: Actually I saw it was just at the Museum of

674
00:40:21,640 --> 00:40:24,160
Speaker 1: the Moving Image and Queens. Oh, yeah, I saw you

675
00:40:24,280 --> 00:40:26,640
Speaker 1: post something about that. Yeah, they have a Madman exhibit

676
00:40:26,680 --> 00:40:30,040
Speaker 1: right now, which is pretty neat, but it was they

677
00:40:30,200 --> 00:40:32,440
Speaker 1: I was not there in time for the Jim Henson

678
00:40:32,440 --> 00:40:34,319
Speaker 1: when they're they're putting that in place, I think for

679
00:40:34,440 --> 00:40:38,479
Speaker 1: later coming coming. What's good You didn't miss it yet? Well, yeah,

680
00:40:38,800 --> 00:40:41,160
Speaker 1: I'll just go back. We went to the Yoko on

681
00:40:41,320 --> 00:40:46,719
Speaker 1: No exhibit at Momah. Awesome. She's something else, dude. She's

682
00:40:46,719 --> 00:40:50,319
Speaker 1: got a pretty cool mind. Yeah, she had She had

683
00:40:50,320 --> 00:40:54,040
Speaker 1: this one display and it was titled three Spoons and

684
00:40:54,080 --> 00:40:58,279
Speaker 1: it was just four spoons in a row. It wasn't three.

685
00:40:59,480 --> 00:41:02,919
Speaker 1: I love that stuff, so I recommend that as well.

686
00:41:03,000 --> 00:41:05,520
Speaker 1: I'm not a fan of her music, though, I actually

687
00:41:05,600 --> 00:41:07,799
Speaker 1: got turned onto her music in the listening room there

688
00:41:07,960 --> 00:41:11,279
Speaker 1: Plastic Band. It's crazy. It's weird stuff, but I kind

689
00:41:11,320 --> 00:41:13,480
Speaker 1: of like it. I mean, she's definitely one of the

690
00:41:13,560 --> 00:41:18,040
Speaker 1: most like original thinkers you know out there, and she's

691
00:41:18,040 --> 00:41:19,520
Speaker 1: been at it for a while, like a lot of

692
00:41:19,520 --> 00:41:22,480
Speaker 1: the stuff went back to the sixties, like the early sixties. Yeah,

693
00:41:22,560 --> 00:41:25,520
Speaker 1: and talk about weathering criticism and still just being like

694
00:41:25,800 --> 00:41:28,319
Speaker 1: screw you. Yeah, I'm Yoko. Oh No, I don't care

695
00:41:28,360 --> 00:41:31,240
Speaker 1: what you say. Well she was exonerated to recently, remember

696
00:41:31,239 --> 00:41:33,400
Speaker 1: Paul McCartney came out and said like, it was not

697
00:41:33,560 --> 00:41:36,200
Speaker 1: Yoko owner that broke up the Beatles and saying that

698
00:41:36,400 --> 00:41:38,520
Speaker 1: it just took him like fifty years to come out

699
00:41:38,520 --> 00:41:42,600
Speaker 1: and say it. Yeah, she's like, would it kill you? Right?

700
00:41:43,280 --> 00:41:46,239
Speaker 1: He told me privately many times, but we'll press release,

701
00:41:46,480 --> 00:41:51,759
Speaker 1: tweet it alright. So we talked about compression and uh

702
00:41:52,040 --> 00:41:55,040
Speaker 1: tension being the two main forces. Uh, there are quite

703
00:41:55,040 --> 00:41:58,040
Speaker 1: a few other forces, dozens even they can act on

704
00:41:58,040 --> 00:42:00,960
Speaker 1: a bridge in a negative way, And the scariest one,

705
00:42:01,520 --> 00:42:05,439
Speaker 1: for my money, is torsion. Um. If you've ever seen

706
00:42:05,480 --> 00:42:09,920
Speaker 1: the video, it's a very famous video of the bridge,

707
00:42:10,200 --> 00:42:13,600
Speaker 1: what is it the Tacoma the Tacoma Narrows Bridge to

708
00:42:13,640 --> 00:42:16,600
Speaker 1: coma narrows bridge when it looks like a wet noodle

709
00:42:17,160 --> 00:42:20,840
Speaker 1: twisting in the wind, Yeah, it was. It's nuts. And

710
00:42:20,840 --> 00:42:23,560
Speaker 1: they have like footage of this whole thing just undergoing

711
00:42:23,600 --> 00:42:27,640
Speaker 1: this destruction that kept just going on and on and

712
00:42:27,640 --> 00:42:30,520
Speaker 1: on and finally the bridges comes down. Yeah. The craziest

713
00:42:30,560 --> 00:42:32,440
Speaker 1: part is when you're watching it, you just think, oh man,

714
00:42:32,480 --> 00:42:34,480
Speaker 1: look at that thing. It's nuts, and thank god, there's

715
00:42:34,480 --> 00:42:36,760
Speaker 1: no one on it, and then you see I continude

716
00:42:36,800 --> 00:42:38,960
Speaker 1: walking on it in a car. Yeah, and a guy

717
00:42:39,080 --> 00:42:41,359
Speaker 1: ran there was a dog. There's one car in there

718
00:42:41,360 --> 00:42:43,440
Speaker 1: and there's a dog trapped in the car, and some

719
00:42:44,000 --> 00:42:49,239
Speaker 1: guy ran and got the dogs. Yes, pretty great heroic stuff. Sure.

720
00:42:49,400 --> 00:42:51,480
Speaker 1: Then later on I don't know if he's the same

721
00:42:51,480 --> 00:42:53,840
Speaker 1: guy and another guy or just two completely new guys.

722
00:42:54,320 --> 00:42:56,640
Speaker 1: They're just walking along it. This is after a whole

723
00:42:56,680 --> 00:42:59,600
Speaker 1: section is falling into the river, but the section they're

724
00:42:59,600 --> 00:43:05,480
Speaker 1: walking still swaying way from the bridge. Step back from

725
00:43:05,520 --> 00:43:09,040
Speaker 1: the bridge, man, So that's torsion at work. Yeah, and

726
00:43:09,080 --> 00:43:12,560
Speaker 1: that's a big problem that designers a suspension bridges face

727
00:43:12,719 --> 00:43:16,600
Speaker 1: because you have a deck that's being held from being

728
00:43:16,600 --> 00:43:19,840
Speaker 1: held alof by cables. Right, it's not like fixed to

729
00:43:20,520 --> 00:43:24,799
Speaker 1: anything below it necessarily mean it's being suspended. So just

730
00:43:24,880 --> 00:43:27,239
Speaker 1: like on like a rope bridge or something like that,

731
00:43:27,360 --> 00:43:30,680
Speaker 1: it sways very easily. Right. Yeah, those towers are strong,

732
00:43:30,760 --> 00:43:33,680
Speaker 1: but it's not, you know, directly connected to those towers.

733
00:43:34,400 --> 00:43:38,160
Speaker 1: So if you have a swaying bridge in between them, right,

734
00:43:39,239 --> 00:43:42,160
Speaker 1: and the thing is swaying back and forth, but if

735
00:43:42,440 --> 00:43:45,400
Speaker 1: one side starts to sway over the other side and

736
00:43:45,440 --> 00:43:47,680
Speaker 1: all of a sudden you have an opposing circular force,

737
00:43:48,160 --> 00:43:52,280
Speaker 1: and that's torsion, and that can basically rip the bridge

738
00:43:52,560 --> 00:43:57,239
Speaker 1: in into which is sheer. Yeah. Well that's the other

739
00:43:57,400 --> 00:43:59,920
Speaker 1: awful thing that can happen. It can just snap, well

740
00:44:00,640 --> 00:44:04,520
Speaker 1: not snap, I guess, but just breaking to two parts. Yeah. Well,

741
00:44:04,560 --> 00:44:08,720
Speaker 1: I mean snapping is the result of compression. Sharing would

742
00:44:08,719 --> 00:44:13,320
Speaker 1: be what it's called technically, where to the same span

743
00:44:13,400 --> 00:44:17,080
Speaker 1: of bridge has the two opposing forces acting on it

744
00:44:17,120 --> 00:44:21,640
Speaker 1: at once, UM, in opposite directions, and it goes it

745
00:44:21,680 --> 00:44:27,520
Speaker 1: makes that terrible sound. Um. If you want to combat torsion, UM.

746
00:44:27,680 --> 00:44:29,759
Speaker 1: Many ways to do this, You're you're probably gonna have

747
00:44:29,840 --> 00:44:33,800
Speaker 1: a deck trust going on to help out. Trust saves

748
00:44:33,840 --> 00:44:36,600
Speaker 1: the day that trust saves the day you're gonna have.

749
00:44:36,920 --> 00:44:40,280
Speaker 1: You're gonna do wind tunnel tests if it's a modern

750
00:44:40,320 --> 00:44:44,440
Speaker 1: bridge beforehand, well you're gonna make a model, yeah, and

751
00:44:44,560 --> 00:44:46,840
Speaker 1: do tests and see like how does wind affect this

752
00:44:46,920 --> 00:44:48,840
Speaker 1: bridge and what do we need to do. But the

753
00:44:48,920 --> 00:44:53,759
Speaker 1: thing is with the um with the Tacoma Narrows Bridge

754
00:44:53,760 --> 00:44:57,520
Speaker 1: in particular, they did tests. They had that thing rated

755
00:44:57,800 --> 00:45:00,160
Speaker 1: with standing winds up to a hundred and twenty was

756
00:45:00,200 --> 00:45:03,479
Speaker 1: an hour. But the winds that day that brought it down.

757
00:45:03,480 --> 00:45:06,200
Speaker 1: We're only forty miles an hour, And for a long

758
00:45:06,239 --> 00:45:10,279
Speaker 1: time they were like, what happened, and somebody said, you

759
00:45:10,320 --> 00:45:15,319
Speaker 1: know what it was? It was mechanical residence. It was. Yeah,

760
00:45:15,400 --> 00:45:20,359
Speaker 1: the deck trust was not sufficient for the span that

761
00:45:20,440 --> 00:45:22,320
Speaker 1: was part of it and the way that the wind

762
00:45:22,400 --> 00:45:25,759
Speaker 1: hit it and the angle calls the final thing that

763
00:45:25,960 --> 00:45:29,440
Speaker 1: you just mentioned residents, which is um sort of it's

764
00:45:29,440 --> 00:45:32,200
Speaker 1: a vibration basically that gets out of hands. So resonance,

765
00:45:32,239 --> 00:45:35,760
Speaker 1: to me, I think deserves its own podcast too. It's awesome.

766
00:45:36,000 --> 00:45:39,440
Speaker 1: Everything every especially anything that we build, from an airplane

767
00:45:39,480 --> 00:45:45,200
Speaker 1: to a bridge, to watch it has a certain frequency

768
00:45:45,600 --> 00:45:50,480
Speaker 1: um where it will really pick up force, really absorbed force,

769
00:45:50,520 --> 00:45:52,600
Speaker 1: it will run through it. Right, So let's say that

770
00:45:52,640 --> 00:45:56,839
Speaker 1: your bridge um has a residence. Uh, that's like at

771
00:45:56,840 --> 00:46:00,719
Speaker 1: a frequency of ten. That's probably a total the ridiculous

772
00:46:00,800 --> 00:46:03,080
Speaker 1: number that I just said. But let's say it's ten, right,

773
00:46:03,600 --> 00:46:05,680
Speaker 1: and then let's say that wind comes at it at

774
00:46:05,719 --> 00:46:08,000
Speaker 1: fort at just the right angle and it makes it

775
00:46:08,080 --> 00:46:11,520
Speaker 1: sway at a frequency of nine, Well, that bridge is

776
00:46:11,560 --> 00:46:13,920
Speaker 1: gonna be It's just gonna sit there and sway. Not

777
00:46:14,040 --> 00:46:16,279
Speaker 1: a big problem. If that wind hits it at just

778
00:46:16,320 --> 00:46:18,560
Speaker 1: the right angle at just the right speed it's and

779
00:46:18,600 --> 00:46:22,480
Speaker 1: it starts swaying at eleven, it's still not quite a problem.

780
00:46:23,120 --> 00:46:25,360
Speaker 1: But if it gets it just right and it starts

781
00:46:25,360 --> 00:46:28,040
Speaker 1: it swaying at ten, all of a sudden, those sways

782
00:46:28,080 --> 00:46:30,439
Speaker 1: are going to become more and more pronounced because all

783
00:46:30,480 --> 00:46:35,040
Speaker 1: that energy is flowing through at its maximum potential and

784
00:46:35,040 --> 00:46:39,440
Speaker 1: at its freest flow, because it's hitting the bridge at

785
00:46:39,440 --> 00:46:44,800
Speaker 1: its natural residence, right. And that's what caused the Tacoma

786
00:46:44,880 --> 00:46:48,600
Speaker 1: Narrows Bridge to come down, because once that thing starts going,

787
00:46:48,680 --> 00:46:51,640
Speaker 1: there's no coming back from it because it's just happening.

788
00:46:51,719 --> 00:46:54,440
Speaker 1: It gets worse and work exactly. And that's that's because

789
00:46:54,440 --> 00:46:56,759
Speaker 1: it hit it at just the right frequency. Yeah, they

790
00:46:56,800 --> 00:46:58,320
Speaker 1: like in it in the article, which I think is

791
00:46:58,400 --> 00:47:02,560
Speaker 1: pretty uh down to earth, the snowball rolling downhill exactly.

792
00:47:02,600 --> 00:47:04,719
Speaker 1: It just keeps getting worse and worse, and that you

793
00:47:04,760 --> 00:47:07,239
Speaker 1: can't stop it. So but isn't that bizarre that you

794
00:47:07,360 --> 00:47:11,400
Speaker 1: a bridge has a natural residence and natural frequency. I

795
00:47:11,400 --> 00:47:15,080
Speaker 1: don't think so, Like I would assume it would vibrate. Yeah,

796
00:47:15,400 --> 00:47:17,160
Speaker 1: it did not occur to me at all. And I

797
00:47:17,200 --> 00:47:20,520
Speaker 1: was talking to Adam about this too, And I was like,

798
00:47:20,560 --> 00:47:24,839
Speaker 1: so I saw that building designers, bridge designers, they will

799
00:47:24,880 --> 00:47:28,959
Speaker 1: fine tune like a structure so that it resonates at

800
00:47:29,000 --> 00:47:32,560
Speaker 1: a frequency that it's probably never gonna encounter from an

801
00:47:32,560 --> 00:47:35,400
Speaker 1: earthquake or from winds or whatever. I'm like, how do

802
00:47:35,440 --> 00:47:38,000
Speaker 1: you do that? And apparently it comes down to the

803
00:47:38,000 --> 00:47:41,560
Speaker 1: building materials you use, the shapes you use to form

804
00:47:41,600 --> 00:47:45,920
Speaker 1: the structure, the way you join those shapes together. And

805
00:47:46,000 --> 00:47:50,000
Speaker 1: you can basically say, I'm giving this building a frequency

806
00:47:50,239 --> 00:47:54,200
Speaker 1: of one point five, whereas I know all of the

807
00:47:54,239 --> 00:47:57,480
Speaker 1: wind in the area and the ground movement from an

808
00:47:57,560 --> 00:48:00,360
Speaker 1: earthquake is going to make it vibrated a free quency

809
00:48:00,400 --> 00:48:04,399
Speaker 1: of seven, so it'll be fine. Yeah. And one way,

810
00:48:04,440 --> 00:48:05,960
Speaker 1: like you said, they can do that is by not

811
00:48:06,040 --> 00:48:09,560
Speaker 1: having like one like shortening the sections of the deck

812
00:48:09,600 --> 00:48:12,960
Speaker 1: plus a and that way the vibration. When you have

813
00:48:13,000 --> 00:48:17,040
Speaker 1: these overlapping plates and smaller sections, it's gonna create enough

814
00:48:17,040 --> 00:48:20,280
Speaker 1: friction to disrupt that frequency. Right, it'll change the frequency

815
00:48:20,280 --> 00:48:22,440
Speaker 1: that the bridge is moving at. But I mean, and

816
00:48:22,480 --> 00:48:24,480
Speaker 1: not just bridges, to you have to take this into

817
00:48:24,600 --> 00:48:28,880
Speaker 1: take into account like airplanes, right, you can't use engines

818
00:48:28,880 --> 00:48:32,920
Speaker 1: on airplanes that create vibrations at a frequency that's at

819
00:48:32,960 --> 00:48:36,520
Speaker 1: the natural resonance of the airplane body. Most the airplane

820
00:48:36,520 --> 00:48:39,600
Speaker 1: body is gonna come apart just from turning the engines on.

821
00:48:39,920 --> 00:48:42,560
Speaker 1: Could you imagine seeing the airplane wings starting to flap

822
00:48:42,840 --> 00:48:46,680
Speaker 1: like harder and harder, Right, But apparently the more common

823
00:48:46,719 --> 00:48:50,239
Speaker 1: thing when you have a disaster catastrophe from a residents

824
00:48:50,400 --> 00:48:54,480
Speaker 1: a mechanical resonance problem. Um, it's like one bolt, it's

825
00:48:54,520 --> 00:48:56,719
Speaker 1: like I can't take it anymore and stops, and then

826
00:48:56,800 --> 00:49:01,000
Speaker 1: that leads to a cascade of failures that aultimately has

827
00:49:01,080 --> 00:49:05,400
Speaker 1: the bridge coming down. Interesting. I think that's fascinating. I

828
00:49:05,440 --> 00:49:08,440
Speaker 1: had no idea that you had to worry about frequencies

829
00:49:08,480 --> 00:49:12,240
Speaker 1: and vibrations. Why all the bridges you've built of collapse?

830
00:49:12,320 --> 00:49:15,480
Speaker 1: They collapsed pretty easy. Well, if you've ever heard the

831
00:49:15,560 --> 00:49:20,400
Speaker 1: old they go down like a French boxer. That means

832
00:49:20,520 --> 00:49:23,760
Speaker 1: I don't need um. But it was a glass Joe reference.

833
00:49:23,760 --> 00:49:29,880
Speaker 1: Remember him from Tyson's punch out, Oh No counter He

834
00:49:29,960 --> 00:49:33,800
Speaker 1: says he was French glass joe. You said, a glass

835
00:49:33,880 --> 00:49:36,360
Speaker 1: jaw and he went down just like a sack of potato,

836
00:49:36,480 --> 00:49:39,800
Speaker 1: so easy. Well, which was it a sack of potatoes?

837
00:49:39,880 --> 00:49:43,080
Speaker 1: Or a French boxer. He was both. He went down

838
00:49:43,080 --> 00:49:46,640
Speaker 1: like a sack of French potatoes. Yes, French fries. My

839
00:49:46,760 --> 00:49:49,960
Speaker 1: bridges go down like a French boxer. But Glass Joe,

840
00:49:50,040 --> 00:49:53,520
Speaker 1: the French boxer went down like a sack of potatoes. Ergo,

841
00:49:53,760 --> 00:49:58,120
Speaker 1: my bridges go down like a sack of potatoes. Um,

842
00:49:58,280 --> 00:50:00,279
Speaker 1: if you've ever heard the Old Wives stay all that

843
00:50:00,440 --> 00:50:04,040
Speaker 1: like an army marching across the bridge and step can

844
00:50:04,080 --> 00:50:07,520
Speaker 1: cause enough vibration to take down that bridge. It's true

845
00:50:08,280 --> 00:50:12,560
Speaker 1: that could happen. So if at the right frequency, right yeah,

846
00:50:12,560 --> 00:50:15,560
Speaker 1: and wartime, that's they will break step. In other words,

847
00:50:15,600 --> 00:50:19,200
Speaker 1: their rhythm isn't all the same to avoid that scenario.

848
00:50:19,480 --> 00:50:21,879
Speaker 1: And there was a bridge disaster I saw on that

849
00:50:21,960 --> 00:50:26,280
Speaker 1: Time magazine slide show where that happened. Um, there were

850
00:50:26,320 --> 00:50:29,720
Speaker 1: there were a pair of skywalk bridges inside the Higher

851
00:50:29,880 --> 00:50:34,560
Speaker 1: Regency Kansas City Hotel, um in the lobby. They were

852
00:50:34,600 --> 00:50:37,920
Speaker 1: just like you know, raised bridges going through the lobby,

853
00:50:38,239 --> 00:50:42,200
Speaker 1: and they collapsed and killed like a bunch of people

854
00:50:42,440 --> 00:50:47,200
Speaker 1: because people people marching dancing. They were dancing on the

855
00:50:47,280 --> 00:50:51,600
Speaker 1: on the skywalk. And you think, like up to today

856
00:50:51,840 --> 00:50:55,640
Speaker 1: or yesterday when I started researching this right, Like, I

857
00:50:55,719 --> 00:50:59,279
Speaker 1: just thought that's weight or pressure, something like if everybody's dancing,

858
00:50:59,520 --> 00:51:02,960
Speaker 1: didn't It never occurred to me that the rhythm had

859
00:51:03,040 --> 00:51:06,160
Speaker 1: something to do. Yeah, i'd always heard that, Well, you're

860
00:51:06,320 --> 00:51:09,520
Speaker 1: far more advanced than I am a structural engineering, my friend.

861
00:51:09,560 --> 00:51:11,799
Speaker 1: Not that. It's just always heard that, like, you know,

862
00:51:11,880 --> 00:51:15,239
Speaker 1: even a bunch of kittens walking across could cause that.

863
00:51:15,360 --> 00:51:17,400
Speaker 1: And the reason they said kittens, of course, is so

864
00:51:17,440 --> 00:51:20,600
Speaker 1: it has nothing to do with weight, right, because kittens

865
00:51:20,640 --> 00:51:23,920
Speaker 1: knowing nothing. And consequently, I think Lina Richie had to

866
00:51:24,000 --> 00:51:25,960
Speaker 1: change the name of that song because of the accident.

867
00:51:26,400 --> 00:51:28,839
Speaker 1: I think originally it was what a feeling when you're

868
00:51:28,920 --> 00:51:32,120
Speaker 1: dancing on the skywalk and he had to change it

869
00:51:32,920 --> 00:51:35,840
Speaker 1: to ceiling and everyone's like, that's weird dance on the ceiling,

870
00:51:35,880 --> 00:51:38,440
Speaker 1: but it rhymes, and he's like, yeah, but nobody ever

871
00:51:38,480 --> 00:51:41,919
Speaker 1: died from dancing on this on the ceiling. I guess

872
00:51:41,960 --> 00:51:45,120
Speaker 1: the final thing we should mention is that weather. Um,

873
00:51:45,239 --> 00:51:47,960
Speaker 1: obviously we'll play a big impact. We already talked about wind,

874
00:51:48,719 --> 00:51:52,120
Speaker 1: but um, over the years, the materials they use in

875
00:51:52,160 --> 00:51:55,680
Speaker 1: the design is gone in to take account things like

876
00:51:55,760 --> 00:51:59,680
Speaker 1: wind and uh what sun damage. I don't know what

877
00:51:59,680 --> 00:52:04,040
Speaker 1: I think get the free stall cycles, huge salt salt exposure.

878
00:52:04,080 --> 00:52:06,640
Speaker 1: If it's going over like a salty body of water,

879
00:52:07,040 --> 00:52:10,360
Speaker 1: that makes sense. Yeah, there's a lot of things that

880
00:52:10,400 --> 00:52:13,560
Speaker 1: are trying to bring a bridge down. Nature abhores a

881
00:52:13,600 --> 00:52:17,839
Speaker 1: bridge basically as much as a vacuum um. I've going

882
00:52:18,320 --> 00:52:22,920
Speaker 1: what's got. There's probably around six hundred and thirty thousand

883
00:52:22,920 --> 00:52:26,440
Speaker 1: bridges in the US alone, because there were six hundred

884
00:52:26,440 --> 00:52:28,799
Speaker 1: and seventeen thousand, nine hundred and thirty five and a

885
00:52:28,840 --> 00:52:32,200
Speaker 1: two thousand two census, and they add them. They were

886
00:52:32,239 --> 00:52:34,839
Speaker 1: adding them at about a thousand a year, maybe nine

887
00:52:34,880 --> 00:52:38,520
Speaker 1: hundred a year. That's just the US. The world's longest

888
00:52:38,560 --> 00:52:43,800
Speaker 1: bridge completed in two ten, the Danyang Coon Shawn Bridge.

889
00:52:43,960 --> 00:52:46,279
Speaker 1: I think I've seen pictures of that. It serves as

890
00:52:46,360 --> 00:52:50,120
Speaker 1: a railway bridge for the Beijing and Shanghai Railway. It's

891
00:52:50,280 --> 00:52:53,640
Speaker 1: a hundred and two mile long bridge that's nutty over water.

892
00:52:54,920 --> 00:52:58,720
Speaker 1: I'm a big fan of cities with multiple water bridges.

893
00:53:00,200 --> 00:53:05,480
Speaker 1: That's why you liked Pittsburgh, Pittsburgh, Portland, Budapest. I'm a

894
00:53:05,480 --> 00:53:07,759
Speaker 1: big fan. Atlanta. Doesn't mean we have bridges, but it's

895
00:53:07,760 --> 00:53:11,480
Speaker 1: not like you have to go to the Chattahoochee River Lakes.

896
00:53:11,640 --> 00:53:15,960
Speaker 1: Nobody goes to the Chattahoochie You know what. Um, I

897
00:53:16,000 --> 00:53:17,560
Speaker 1: got one more thing I want to shout out to

898
00:53:17,840 --> 00:53:21,600
Speaker 1: PBS is build it big website, which is like beyond

899
00:53:21,719 --> 00:53:25,600
Speaker 1: nineties as far as websites go. But it was extremely

900
00:53:25,640 --> 00:53:29,520
Speaker 1: helpful and understanding the forces that work on bridges, different

901
00:53:29,520 --> 00:53:34,399
Speaker 1: types of bridges, different specific bridges. Great website and thanks

902
00:53:34,440 --> 00:53:36,680
Speaker 1: to Adam. I guess you got some information from him. Yeah,

903
00:53:36,680 --> 00:53:38,600
Speaker 1: thanks Adam. Was he into talking to you about it?

904
00:53:38,680 --> 00:53:41,200
Speaker 1: Or was he on the other end going oh my god,

905
00:53:41,280 --> 00:53:43,440
Speaker 1: justsh shut up and watching Tim and Eric? He was

906
00:53:43,719 --> 00:53:46,040
Speaker 1: he was into talking about it. I figured he would

907
00:53:46,080 --> 00:53:48,480
Speaker 1: be yeah. Uh. And I actually have to shout out

908
00:53:48,480 --> 00:53:49,719
Speaker 1: to you mean too because I told her we were

909
00:53:49,719 --> 00:53:52,480
Speaker 1: building bridges, or well, we were talking about bridges. She

910
00:53:52,560 --> 00:53:55,359
Speaker 1: sent me a bunch of stuff on popsicle bridges. Um,

911
00:53:55,400 --> 00:53:59,880
Speaker 1: apparently there's a a Indie Go go for the world's

912
00:54:00,040 --> 00:54:05,520
Speaker 1: strongest or Canada's strongest popsicle bridge. Yeah, they're trying to

913
00:54:05,520 --> 00:54:11,160
Speaker 1: build that. Yes, and they start six screened already for

914
00:54:11,320 --> 00:54:15,080
Speaker 1: out of popsicle sticks. Good for them. So that's everybody

915
00:54:15,080 --> 00:54:17,920
Speaker 1: getting shouted out to all over the place in this one. Huh,

916
00:54:17,960 --> 00:54:21,040
Speaker 1: that's nice stuff. Bam. If you want to know more

917
00:54:21,080 --> 00:54:23,440
Speaker 1: about bridges, you can type that word into the search

918
00:54:23,480 --> 00:54:26,799
Speaker 1: part how stuff works dot com. And since I said

919
00:54:26,800 --> 00:54:32,680
Speaker 1: search parts, time for listener mayl. I'm gonna call this.

920
00:54:33,160 --> 00:54:36,399
Speaker 1: I got a couple of street gang responses. Will read

921
00:54:36,400 --> 00:54:40,520
Speaker 1: over the next couple of shows. Um, here's one. I

922
00:54:40,560 --> 00:54:42,440
Speaker 1: had to write in about your street gangs episode as

923
00:54:42,440 --> 00:54:45,320
Speaker 1: it was interesting pertains to my job. Short version is

924
00:54:45,320 --> 00:54:47,520
Speaker 1: that I worked for a hospital based program and we

925
00:54:47,560 --> 00:54:50,040
Speaker 1: see every gunshot wound victim and stab wound victim who

926
00:54:50,080 --> 00:54:53,520
Speaker 1: comes through, which is about four year UM, and about

927
00:54:53,560 --> 00:54:56,560
Speaker 1: ten percent of those are gang involved. How you guys

928
00:54:56,560 --> 00:54:58,080
Speaker 1: have mentioned how you found the number of gangs to

929
00:54:58,120 --> 00:55:00,080
Speaker 1: be hard to believe, but I think you may you

930
00:55:00,120 --> 00:55:02,520
Speaker 1: thinking the street gangs is one entity that has strict

931
00:55:02,520 --> 00:55:05,960
Speaker 1: borders and lots of people. And my experience, larger gangs

932
00:55:06,000 --> 00:55:09,319
Speaker 1: will sometimes incorporate smaller gangs, and sometimes larger gangs will

933
00:55:09,320 --> 00:55:13,120
Speaker 1: split off into many many smaller groups. Uh. People go

934
00:55:13,160 --> 00:55:15,000
Speaker 1: in and out of gangs and are sometimes affiliated with

935
00:55:15,000 --> 00:55:17,480
Speaker 1: more than one. Currently, we have about at least seventy

936
00:55:17,480 --> 00:55:20,120
Speaker 1: in our city alone, and a substantial amount of those

937
00:55:20,160 --> 00:55:23,799
Speaker 1: have less than twenty members, so like many gangs, not

938
00:55:23,920 --> 00:55:26,719
Speaker 1: super gangs, not super gangs. According to this paper on

939
00:55:26,760 --> 00:55:29,440
Speaker 1: street gangs in Boston, eight percent of the gangs in

940
00:55:29,520 --> 00:55:33,680
Speaker 1: the city have less than ten members and have ten

941
00:55:33,760 --> 00:55:38,240
Speaker 1: to nineteen members. So while the numbers you gave seem

942
00:55:38,280 --> 00:55:40,480
Speaker 1: shockingly high, they also seem to be in step with

943
00:55:40,560 --> 00:55:44,160
Speaker 1: the current climate. And that is from Arianna. And what

944
00:55:44,280 --> 00:55:46,839
Speaker 1: city did she say? You know, I don't see that.

945
00:55:46,920 --> 00:55:49,319
Speaker 1: I don't think she said. I don't know if it

946
00:55:49,360 --> 00:55:51,759
Speaker 1: was Boston or if she just referenced Boston. Well, thanks

947
00:55:51,800 --> 00:55:55,000
Speaker 1: a lot, Ariana. We appreciate that email. And yeah, keep

948
00:55:55,040 --> 00:55:57,000
Speaker 1: them coming. We wanted them more about gangs. I just

949
00:55:57,040 --> 00:56:00,560
Speaker 1: had the impression the whole time that like one or another,

950
00:56:00,680 --> 00:56:07,600
Speaker 1: we were officially or unofficially misinformed. H And also let

951
00:56:07,680 --> 00:56:10,399
Speaker 1: us know who's the coolest famous person you've ever met?

952
00:56:11,480 --> 00:56:14,520
Speaker 1: You can tweet to us that that's why sk podcast.

953
00:56:15,000 --> 00:56:17,360
Speaker 1: You can join us on Facebook dot com, slash stuff

954
00:56:17,360 --> 00:56:19,400
Speaker 1: you Should Know. You can put it in an email

955
00:56:19,440 --> 00:56:22,120
Speaker 1: to stuff Podcast at how Stuff Works dot com and

956
00:56:22,160 --> 00:56:24,000
Speaker 1: has always joined us at our home on the web,

957
00:56:24,080 --> 00:56:32,080
Speaker 1: Stuff you Should Know dot com. For more on this

958
00:56:32,239 --> 00:56:34,759
Speaker 1: and thousands of other topics. Is it how stuff works?

959
00:56:34,800 --> 00:56:42,480
Speaker 1: Dot com