Since nobody makes code 100 bridge track, and at the time code 83 seemed to be unavailable, I made my own from flex track. Chuck (tomikawatt) suggested this. I started with Atlas flextrack and pulled the ties off a section, carefully so as not to break the webbing that holds the track in place. I cut the separating pieces from the ties, and then slid them back on, maintaining a tighter spacing manually. For the guard rails, I took old sections of brass flex track, shaped the ends and glued thm on.
This is a shorter, lower bridge track over a trestle. I used the same technique here, but in this case I used an old piece of brass flex track for the "donor" ties, which are noticeably wider than the newer ties.
I added guard rails to this section, too, after the picture was taken.
It takes an iron man to play with a toy iron horse.
Thanks for the reply Mr. B nice work on the home made bridge track. I totally understand what you did with tie spacing etc. but I unfortuently don't have your paitents. nice job.
One way to avoid bridge track is to use all ballasted deck bridges. Deck girders (with troughs on top of the girders,) through girders and concrete or stone arch bridges can be crossed by ordinary track ballasted in the ordinary manner.
Railroad MW departments actually prefer ballasted decks, which are cheaper to maintain and keep aligned and don't require non-standard parts like bridge ties. The engineering department may be less happy - the basic bridge has to be a bit stronger, to hold up the rock ballast as well as the trough that contains it.
Chuck (Modeling Central Japan in September, 1964)
Probably due to the spectacular bridge failures of the nineteenth century, twentieth-century bridges were typically over-engineered and could usually be retrofitted with ballasted decks.
Here is some information gleaned from some Southern Pacific Common Standard Plans covering early and mid-twentieth century practices regarding open-deck bridges.
On wooden trestles, ties were 8"x8"x8' on 15" centers.
On steel bridges without sidewalks, ties varied. Heavy traffic lines used 10" wide ties, light weight traffic lines used 8" wide. The length and depth of the ties varied based on the center-to-center distance of the bridges girders or stringers. From a minimum distance of 6'6" the depth was 9.5" and the length 9', to a maximum distance of 12' the depth was 15.5" and length 14'. So, it wasn't unusual to see ties of different lengths used for different parts of bridges as for example a wooden trestle connected to a steel bridge. The 4"x8" guard timbers near the ties' ends would be transitioned for the change in tie length.
Superelevation on curves was achieved by tapering extra-deep ties.
A ballasted deck might be 16' wide on a wooden trestle and edged by vertical 4"x12" boards with diagonal 2"x3/8"x2'10" steel braces buried under the ballast except for exposure at the top of the boards. Regular ties and spacing were used. Rail size for the running rails would be the same as elsewhere on the line, although the guard rails could be somewhat lighter. Scrap rail was used for this purpose. For example, if the running rails were 110# per yard, the guard rails might be 90#.
A ballasted deck on a double-track wooden trestle with 14' track centers would be 30' wide.
Ballasted deck wooden trestles would have more stringers than one with an open deck because the deck bottom needed to be supported over its entire width although there could be gap between the stringers under the rails and the stringers supporting the deck's edges.
Thanks for the replys but I feel some are missing the point of my questions. I know about the different types of bridges etc. But I am not about to replace a 250' timber trestle bridge (which is there strictly for the visual effect) with a ballasted truss bridge or viaduct or stone arch bridge etc.
I can simply avoid using bridge track period if I choose to but thats not what I'm looking to do. I want to know the why's of running code 70/ 83 or should it just be code 83/83. Also are there any protype bridges that do not run bridge track or is it something that is a standard.
Allegheny2-6-6-6 Thanks for the replys but I feel some are missing the point of my questions. I know about the different types of bridges etc. But I am not about to replace a 250' timber trestle bridge (which is there strictly for the visual effect) with a ballasted truss bridge or viaduct or stone arch bridge etc.
You didn't say what specific type of bridge you were talking about. You said you had several. We aren't mind readers here.
Allegheny2-6-6-6I want to know the why's of running code 70/ 83 or should it just be code 83/83.
Could it be a simple confusion of running code 83 track with code 70 guard rails? (Or code 100 with code 83 guard rails). Many prototypes used lighter weight guard rails. Probably cheaper and maybe made from leftover rail salvaged from upgrades. It looks pretty good and IMHO you should keep the weight of the rails consistent from land to bridge back to land.
Karl
The mind is like a parachute. It works better when it's open. www.stremy.net
The Micro Engineering code 83 bridge track comes with code 70 guard rails:
I don't recall if the guard rails here were lighter than the running rails or not:
Wayne
Thanks DR Wayne Great shot by the way, I'm going to a LHS some time today to pick up some Micro Engineering bridge track but I follow what you are saying that it's a code 83 rail with a code 70 guard rail. I guess to can't spell things out simple enough some times