Gary S' 2010 Summer Challenge - Bridge

[Puddlejumper]

Those were two VERY wise men. Build it the way YOU like it.

Interesting that the prototype is asymmetrical... I would not have expected that.

[Gary S]

Andrew - you caught me! :oops:



Dave, I did not expect that either!

[P5se Camelback]

O.K. ... being sort of a structural kind of guy, albeit not anything near a structural engineer, I would still ask ...

Which way does the water flow in that stream ... er, ah ... bayou? Does it ever flood there? When it does (if it does,) how quickly does the water pass by the trestle bents? I mean, from what I can see from here, the next set of bents (actually in the water,) as well as the set beyond (still in the water but by the other edge) also have the same "peculiar alignment" as the set you pointed at with the red arrows.

(And, hey, Arlo ... are there also paragraphs on the back of that photo with the arrows on it? I mean, what with your run-in with the sherriff and all ... i was just wonderin' ... back here at the restaurant. )

I'd say, if you're building a model of that bridge, build it like that bridge ... otherwise, just build a freelaanced bridge. I'm jus' sayin'.

[Gary S]

biL, you one very smart fellow! You nailed it on both accounts!

First, the water flow in the last photo is from right to left. With a heavy rain (which we have fairly often), this bayou will fill up completely to the banks and the water moves pretty fast. So the angled supports are to help resist the water flow.

Second, as you mention, if I am modeling a prototype bridge, I need to model the prototype bridge! While it may be true that the only person I have to please is myself, since this is a contest entry, I also need to impress the voters! And sticking to the prototype may be more impressive than if I didn't.

As I study the bridge, I am finding more interesting details. For example, the bents near the abutements have four pipes, then there is a bent with five pipes, then bents with doubled fours! Pretty interesting and unexpected.

   

[Gary S]

(And, hey, Arlo ... are there also paragraphs on the back of that photo with the arrows on it? I mean, what with your run-in with the sherriff and all ... i was just wonderin' ... back here at the restaurant.

Woah! That photograph with the red arrows seems just a little bit, er.... very very suspicious! :o

[Gary S]

I did get some stuff accomplished tonight. Installed the top of the bridge and the ballast retainer cap on one side and the footwalk on the other. Started on the bent caps too. I need a bunch of 5/32 tubing to make the 14" diameter pipe, need about 16 feet actual feet of that. The LHS didn't have any when I was there yesterday. I'll stop by another shop tomorrow.

   

Andrew: Even though I am modeling from the prototype, I still reserve the right to invoke the three foot rule!

[nachoman]

That DIN rail is a very good idea. I have used 1x2 pine as a "core" for deck plate girder bridges for a similar purpose. I wanted the thing to be strong and not have to rely on styrene for rigidity. Now your supports don't actually have to "support" anything.

[P5se Camelback]

Hmmm ... The three foot rule ... is that in any way similar to the three second rule (as it relates to dropped food) or is it just that it's tired, I'm late (and punchy) and should go back to bed?

Oh ... and BTW ... I'm not so sure about "smart" ... but I am observant, and I question things constantly (as any good designer would.) So often when I don't really know the answer, I'll make a semi-educated, reasonably deductive, often "right-on-the-button" guess. Just uncannily lucky, I suppose!

But dumb luck aside ... I'm quite pleased that my nonsensical comments caused you to investigate ... to seek answers for my queries and in the process, learn valuable tidbits of information that will help in your efforts to represent this bridge with a realistic model ... one with a reason for being ... or dare I say it ...
... a raison d'etre.


That bridge is one that just drips character ... I'm glad you chose that one!

[Sumpter250]

In your photo, with the red arrows, the legs are equidistant at the top, and the two to the left show as angled out at the bottom. Model what you see, there's a reason for the angled legs. ( look at any timber trestle, you'll see the same thing )

" The proto bridge was approx 290 feet on Google Earth. The model is exactly 1 meter long, 39.37 inches, or 285.4 scale feet."

Thankyou for the verification. I used your Xacto knife as a reference to determine the width of the model, and then used the width to determine the length. That I got so close to your determination of the prototype length, verifies the process. I got 40" which converted to 290'.

[nachoman]

That's okay, Gary. Picturesque is in the eye of the beholder, as evinced by all the atrocious architecture and modernistic big box structures littering the landscape. Dadgum ugly if you like 'traditional' buildings, but really cool otherwise. I like the look of the river channels in SoCal. Had I stuck around long enough to build a module for my club, I would have most likely included one.

When I was in grad school, oil company representatives would come visit our department about once per year. They would require everyone to interview, give a schnazy presentation (more sales pitch than science), buy us beer and food, and try and bribe us with women. Our department got LOADS of funding from oil companies. Enough to take out-of-state class field trips, new computers, and pay half the professors' "salaries". I could never quite figure out what was in it for them. I think they hoped students would be lured by the appeal of the presentation, and be more open minded about living in Houston! That was their toughest sale - they would hire people right out of school at 75-80k per year, give tons of great benefits, yet still students were reluctant to agree to move to Houston. It definitely is not what I call "ideal" scenery. But, as Galen says "beauty in the eye of the beholder" - and certainly will make a unique and interesting model railroad layout. If you get these bayou areas done right, they will be a very unique "landmark" identifier for your layout.

[Gary S]

That DIN rail is a very good idea. I have used 1x2 pine as a "core" for deck plate girder bridges for a similar purpose. I wanted the thing to be strong and not have to rely on styrene for rigidity. Now your supports don't actually have to "support" anything.

Kevin, another thing I have considered is the plastic trim available from HD. They make various shapes and sizes in solid plastic instead of wood. Some definite possibilities there. With wood, I might be concerned with warpage over time.

[Steamtrains]

I take it back....
I thought only that one bent was "out of shape". But seeing that all are the same, there would be a purpose behind it, and bIL nailed it..!! Build it like the man did...

P5se...Is Alice still around..??

[ocalicreek]

I say go with the "bent" bents and model it just like the prototype. Real life is almost always more interesting than anything we can dream up, I say. But still I'm not a strict prototype modeler, since the 'interesting' bits, like this bridge, aren't as common as the ordinary remainder of reality.

Made me think of a neat bridge on Jack Burgess's Yosemite Railroad layout. The bents are all different heights and widths and it really looks different than the usual timber trestle (which I must say, there's nothing wrong with an ordinary, run-o-the-mill trestle). But it sticks out in your mind.

You could find a nice picture of the prototype and mount it on the layout fascia, so folks would know you based it off a real location and could see how it translated onto your layout.

Now don't go getting a big head over this, but personally, I think you'll have a 'cover shot' location for your layout once you get this thing built and installed. If not a cover, at least a photo section submission.

Galen

[Gary S]

Hmmm ... The three foot rule ... is that in any way similar to the three second rule (as it relates to dropped food) or is it just that it's tired, I'm late (and punchy) and should go back to bed?

biL, the three foot rule is as follows: When running trains on a shelf layout, our eyes are typically three feet from scenes and trains. So any detals that are too small to be seen from three feet are basically wasted effort. But to be honest, I invoke the three foot rule as a cover for my lack of patience with the small details and my lack of modeling skills!

Oh ... and BTW ... I'm not so sure about "smart" ... but I am observant, and I question things constantly (as any good designer would.) So often when I don't really know the answer, I'll make a semi-educated, reasonably deductive, often "right-on-the-button" guess. Just uncannily lucky, I suppose!

Well,. biL, I just want to tell you that you have brought a fresh outlook to Big Blue, and your background in design shows, and I appreciate that. Glad that you decided to stay here!

But dumb luck aside ... I'm quite pleased that my nonsensical comments caused you to investigate ... to seek answers for my queries and in the process, learn valuable tidbits of information that will help in your efforts to represent this bridge with a realistic model ... one with a reason for being ... or dare I say it ...
... a raison d'etre.


That bridge is one that just drips character ... I'm glad you chose that one!

The more I look at the bridge, the more I like it. It is definitely not the norm for a model layout. One of the things that drew me to this bridge is the pipe columns - the lack of symmetry and the white paint with all the rust. Since weathering is one of my favorite things to do, I'll have plenty of it with this bridge.

[Gary S]

In your photo, with the red arrows, the legs are equidistant at the top, and the two to the left show as angled out at the bottom. Model what you see, there's a reason for the angled legs. Look at any timber trestle, you'll see the same thing.

But the odd thing is the asymmetry from one side to the other. And also the asymmetry from bent to bent. And then there is the asymmetry between the spans. The three spans on each end are 25 feet, the four in the middle are 35 feet. The middle three bents at the 35 foot spans are doubled fours, but the two on the ends of the 35 foot spans are single fives. And the other ones under the 25 foot spans are single fours. I'm sure it is all based on sound engineering practice.

RE: length of bridge:

Thankyou for the verification. I used your Xacto knife as a reference to determine the width of the model, and then used the width to determine the length. That I got so close to your determination of the prototype length, verifies the process. I got 40" which converted to 290'.

Great method on determining the length. I've been using similar methods with the bridge photos to determine dimensions.