Layouts and layout building

I have a double track that crosses a river on my layout. Originally I was going to build a wooden trestle and then thought about either a small coffer or flood control dam or just building a small hill around the tracks. I am leaning toward the dam idea, as there is a dam near where I live that I'd like to model. I know that prototypically it is rare to have a track crossing a dam and even rarer to have double tracks, but I think it might be an interesting element. Here is a shot of the area. I have done a bad photoshop job to try to get even some idea of what a dam might look like. Any feedback on other ideas of how you might treat this area?

When I started reading your description of what you wanted to do, the first thing that came to my mind was a mental image of Hoover Dam in Nevada/Arizona.  It's big and tall with a huge lake behind it.  I couldn't imagine any railroad laying tracks across the top of that dam.  I think they would have built a bridge separate from the dam.  (Incidently, there has been a road on Hoover Dam since it was built, but a new bridge is being built high above the dam to replace the roadway on the dam.)

Looking at the photoshop picture you made, I think it could turn out well.  You're not making a bid dam, more like a flood control device.  It wouldn't necessarily have a large lake behind it, or have water up close to the roadbed.   It think the railroads would avoid having tracks too close to a body of water that could cause erosion of the roadbed.  Under the right circumstances, the railroad probably would have built the "dam" when laying out the line.

Looks like it could be a fun project.  Keep the size about what you show in the picture and it will look in scale to the area.

Darrell, quiet...for now

Building a railroad across the crest of Hoover Dam would involve some really significant tunneling through the sheer cliffs at both ends!  Just bringing materials to the site called for some major tunnels - one of which, 1600 feet long, was drowned when the lake filled.

What you've done doesn't look unreasonable.  I would prefer to think that the rails were there first, possibly on a steel viaduct or a masonry arch structure, and the dam was built under them.  Maybe it was a WPA project.

Chuck (Modeling Central Japan in September, 1964 - possibly with a diversion structure in the Tomikawa)

When I first read this thread, the thought occurred to me that a heavy duty rail line running along a dam MIGHT cause some vibrations and harmonics that could damage the dam itself.  I have seen curved dams in Kansas and other places for automobiles, but not rail lines, and as I said, I would wonder about the virbration.  You need to talk to an engineer (not a train running engineer) who specalizes in roads running over dams and the effect of vibration.

Bob

The dam near my home is a flood control dam and it has a road on top of it. I have only found one actual dam with a railway on top, but I assume it could work. I will take some pictures of the dam next week and post so you can see what it is like. It has 5 flood control gates, but I would make it small - only one or two, or even just design it as a coffer (overflow) dam. I think railways probably shy away from running on dams due to risk of flooding or ice jams. Here there is a railway bridge across the lake upstream from the dam - only a few hundred feet or so away.

Here is a picture of the road across the dam:

This is not a great picture, but the only aerial shot I can find on the internet. You can see the railway bridge at the top right crossing the lake.

Good point, Pastorbob!  Hadn't thought about the vibrations.

I don't know what effect vibrations would have on a dam.  Given the small size that the OP shows in his photoshop image, I'd imagine that it could realistically be done.  But then, I'm not looking at it as a dam, just a flood control device.  There would be a big difference.  Dams usually have provisions for using the water that flows through them, where flood controls merely regulate the flow of water.

It's an interesting situation.  It'll take some thought to make it believable.

Darrell, quiet...for now

How about a levee?  The town I grew up in had a depot and tracks on top of the levee.  In the 50s my dad owned the Gulf station across from the depot.  It's hard to see from the picture, but the water level was about eight feet above the gas station parking lot.  What's not shown is the trestle to the tracks on the other side.  They too ran on a levee to the cotton mill and power plant using a switchback.  If you built this configuration on a model railroad, no one would believe it's prototypical.  Let's see if this picture link works.

http://digital.tcl.sc.edu/cdm4/item_viewer.php?CISOROOT=/rrc&CISOPTR=1583&REC=4

A railroad crossing a bridge that sinks to allow boats to pass makes much more sense.  (Only a two-lane road and pedestrian lane pictured here.)

I can't imagine a busy, double-tracked railroad passing over a dam.  Haven't heard of any, and the vibrations and loads of heavy railroad traffic, as well as the resulting reduced access to the dam, makes such an arrangement appear impractical..

You also seemed to have reduced the scale several-fold of the dam to make it fit.  The result is strange-looking.

May I suggest you place a photo of a distant view of the dam on a backdrop and have the railroad cross the river downstream?  I wouldn't recommend a wooden trestle, however.  You'll need a bridge that can stand up to open flood gates..

Mark 

If I remember correctly, the Montreal River trestle on the Algoma Central Railway (now part of CN) has the steel legs buried in the dam.  The railway was there first, but the shortest crossing of the valley is the preferred one for dam building too.  I imagine a search of the web should be able to turn up a picture or two since the Agawa Canyon tour train runs across it regularly.

John

hi Aralai,

I like Chuck's idea; a stone arch bridge and you don't even need a dam.

Your photoshop work ain't that bad at all, it is pretty good. You found yourself a great solution.

have fun, keep smiling

Paul 

Hard to judge by the scale, but it didn't want to go with a bridge would the railroad just go for a big culvert (or perhaps 2 medium channels side by side)?

Crossing the Mississippi River at Keokuk, IA, is an electrified railway that runs on top of the dam in the river.

Here is a panoramic photo:

http://users.stlcc.edu/jangert/keokuk/scroll.html

To the left is the highway bridge leading directly into downtown Keokuk.  Pan to the right and you will see the dam as it crosses the river and meets the power generating station.  Look closely at the top of the dam where it meets the building and you can see one of the motor cars used on the rail line.  If I am not mistaken, the line is all but abandoned now.  It was used to bring coal across the river to the powerhouse.

This was a purpose built rail line and didn't carry mainline traffic or any heavy locomotives.  That doesn't mean you can't run a rail line across a dam; like many other un-prototypical ventures, it's probably been done somewhere.

Darrell, quiet...for now

Darrell, I see bridges in the photo but no dam.  Am I blind?

Mark

Following up my earlier post, here is a link to the trestle across a dam. Of course it is not directly relevant to your situation but it does prove that rail bridges and dams can be combined.  Your solution as shown by photoshop is reasonably credible.  The  biggest problem is watching out for the dam details.  The operator will need to be able to adjust the sluice gates without affecting the railway, so they shouldn't be directly underneath the bridge.deck.

John

 http://www.railpictures.net/viewphoto.php?id=136452&nseq=0

 Thanks for all the feedback. The photoshop picture is just to kind of give the idea - obviously the dam in that picture is much too large. I think that a smaller structure - somewhat larger than a culvert but with only one or two openings would be best - I think if scaled properly it will look ok. I'll keep you posted on progress.