MEI Bridges in HO Scale

[Anonymous]

I'm working on a Micro Engineering, Inc. bridge kit for my HO Scale railroad. It is a two span double track through girder bridge. The MEI kit is intended for a bridge on a ninety degree angle with the piers, but mine will be built at a seventy degree angle to the piers (which is called a twenty degree skew). Let me know if you are interested.

[Anonymous]

Dan,

I presume you are building your bridge on a ninety degree angle. If you are building it on a skew, then we have alot to talk about.

First, I would just put a piece of wood there and come back in and install the bridge later. Just set the wood in there loose and you can pull up the track and the wood block and install your bridge anytime.

Next, I'm a little fuzzy about your comment that the bridge is not long enough. Are you using the 50 ft span(s)? Is it long enough. How long is the gap you are crossing? Can you use as many piers as you want or do you need the clearance under the bridge?

Abutments:
I am building my own for the skewed bridge beacuse nobody makes anything like this. I bought some Scale Crete and it works great for making concrete substructure (Piers and Abutments). Just make the shape you want out of wood and then coat it with Scale Crete. An abutment has two elements always, a backwall and a seat. The backwall would normally be about one foot to eighteen inches thick to retain the fill just behind the bearings. It goes from the seat to the subgrade of the track and is usually twice as wide as the track. The seat is where the bearings rest. The seat should be from two foot six inches to four feet wide, as wide as the girders plus four feet and at least two feet deep. If the seat is shallow like this then it is referred to by some as a shelf abutment, the smallest you will see. If the abutment is taller then the seat will extend all the way to the ground. This is the type of abutment you usually see advertised and is something like thirty feet high. I think Chooch makes a nice one (a cut stone and another type) but now that I have my Scale Crete I can make my own for real cheap. Most abutments also have wingwalls to retain the fill beyond the seat area. The site conditions and some personal preference will dictate how these are laid out in plan. Some engineers like to extend them on the same line as the backwall, others like to flare them back away from the opening under the bridge. If you think scour is likely, then I would flare them back and place rip-rap (like talus) around the base of the wingwalls.

Let me know some more about your intentions(sp?) and I will see if I can help further.

Good Luck - Ed

[DocDan]

I guess I'm in the deep end of the pool here talking bridges with a bridge engineer but yes I am interested. It sounds like what you are doing with your bridge is what I should be doing with mine only I'm not sure how. The bridge is constructed and painted (but not weathered yet). It is currently configured with the "concrete" subroadbed and it will carry ballasted track.

As I mentioned, I have about 3" to spare on both sides of this bridge right now. So , I wonder if I should attach the bridge to the track right now and let it "float" in that space until the stream is completed and the abuttments installed.

I am most definately interested in your setup for this bridge. It sounds very interesting and appropriate for my situation since the stream takes a turn at about the point where this bridge is crossing. I guess the thing that would cause me to shy away from this project is if I have to modify the girders in any way (i.e. cutting them down or reshaping them).

Thanks for your help.

[DocDan]

Ed,
Please disregard my previous post. I just realized you posted an elaborate reply to my earlier post. I'mgoing to read it carefully and get back to you. Thanks.

Dan

[Anonymous]

Dan,

I came up with a way to 'extend' your bridge the approx. 4 inches. Add a MEI 30 ft span to one end. I laid out the framing plan at work today so if you send me your e-mail address we can discuss further and I can send you a sketch.

I worked out a plausible scene involving a repair of a washed out bridge approach. I think you may like it but it may not fit into your plans. Let me know if you want to hear more. - Ed

[DocDan]

Ed,
Your previous long reply was very helpful and at the very least, it taught me the correct use of the Chooch abutments I purchased. Now I know where to seat the bridge.

In fact, my plan now is to simply use those Chooch abutments with the MEI bridge and bring the scenery right to the back of the those walls. Of course, now that leaves the other bridge at another location (a Walthers double track tresle)without abutments. But, I may simply make my own using your Scale Crete idea. BTW, where did you get the Scale Crete? Walthers doesn't carry it in their most recent catalog.

In any event, my email address is [e-mail]. I'd like to see your plans for the washed-out bridge. It sounds like a very interesting idea.

Dan

[Anonymous]

Dan

I'll contact you at your e-mail address for the rest of this since it could be a little long. For anyone else who may be interested, I last noticed Scale Crete on sale at a hobbie shop three or so years back. The label says:

Distributed by C S Design, Inc. - Valparaiso, IN 46384 [phone] c 1990

I like the stuff.

Later - Ed