beginning bridge

[Anonymous]

ok, thank you guys for all your help. I think I will go with what you suggested.

[Anonymous]

There is little anyone else can tell you because I think your other helpers have told you the most logical answers. I think you should build a trestle and then have a thing like a cement holder that loads the cement trucks and then at the bottom of that have a shutte like one that loads a grain trailer attached to the opening. This would allow the gravel to travel at a slow rate without getting stuck and it wouldn't beat up the trucks as much...

[CNJ831]

As Ed has already indicated, probably the most common arrangement for this sort of operation would be a wooden trestle, most likely of braced pilings or heavy timbers. While scratchbuilding this structure would be the ideal way to go, you indicate that you are a relative beginner. So, might I suggest modifying Walthers #3147 trestle. Cutting off the lower half of each set of piers (just below the horizontal brace)would bring them to about the right height for truck loading operations and it should prove to be an easy kitbash. Open up a short section of the trestle's deck at some suitable point for offloading the hoppers into the trucks, attach a small, tapered deflector below the track deck to direct the flow of gravel into the trucks, and you're all set.

John

[Anonymous]

Michael,

I had to read you message twice before I understood what you were trying to do. Let me make sure ...

You are going to have a section of HO scale track 24 inches long over a section of scenery about two inches below which represents a loading area to transfer gravel from hoppers to trucks.

This is similar to a railroad operation where they dump coal to be used at a power plant or transferred to a ship by conveyor. It may seem efficient to load trucks this way, but it would probably beat up the trucks pretty much. The railroad would probably build a trestle of twenty foot spans across your site using wood. If you look around you will see an example of this done for a coal operation. The trestle will be open to allow the gravel to flow through and there will have to be baffels to control the gravel (sort of like a funnel) into the trucks and to keep it from free falling into the trucks.

Another way of doing this would be to build a sloping ramp under the trestle and to one side. The gravel would be dumped onto the ramp and it would accumulate in a long pile next to the trestle. Then a front end loader could scoop it up into the trucks when they arrive. A large crane could be used if you think that is more interesting.

I recently saw a 'yard office' and a 'guard shack' which would be nice for this kind of scene. I would also put 'chain link' fence around the whole site with a 'No Trespassing' sign every 100 or so scale feet. Then I would 'pave' the entrance and a few feet of the area inside the fence with Scale Crete to look like a parking area. Cover the balance of the parking/loading area with stray gravel, and you will have a nice scene indeed.

To get back to your question about bridges ...
A railroad span of 200+ feet would be quite a substantial structure. Certainly they would have to use a truss. The cost of a truss like this is staggering when compared to a multi-span trestle of wood. That is why I think you should use the trestle.

Central Valley makes a 150 ft truss span for a single track bridge. I think the Walthers truss is about 200 ft but it is made for a double track situation. Plastruct has a set of plans for a truss which could be modified for your situation, but I am not sure how much it would cost to build the Plastruct version.

Good Luck. - Ed

[Anonymous]

umm, just to clarify, it is HO scale, so (according to a chart I found on this site), its 217 scale ft.

[Anonymous]

Hello all,

I'm somewhat new to scenery (up until a little while ago green paint substatuted for grass on a flat layout), but I am looking for some help. I am currently dropping a section of my layout a few inches and am planning to suspend a section of railroad over it. the thing is the section is only about a foot or two long, and is going to be suspended over a gravel pit so that hoppers would be able to drop their cargo into awaiting tucks below. Any suggestions on what type of bridge to build?

Michael