I am adding a deck bridge to the layout and have the bridge track with out any guard rail. I want to add the guard rail. Am wondering how far to extend the guard rail into the regular track after coming off the bridge? Any help would be appriciated.
Thanks
John
In real life it was to the end of the bridge at least and varied on how far past, seen it from a few feet to a car length or more and the ends I have seen everything from slightly bent in and down to an actually point (never understood why it would end in a point because by then the cars would have been almost totally derailed anyway).
i always figured guard rails and timbers were not intended to prevent derailments, but to keep the train from falling off the bridge if it did.
grizlump
I've found the prototype pictures at www.historicbridges.org to be really helpful in figuring out stuff like this. Just browse around the site and you'll find several examples.
Here's one from the site showing bridge track and guard rails
rrebell In real life it was to the end of the bridge at least and varied on how far past, seen it from a few feet to a car length or more and the ends I have seen everything from slightly bent in and down to an actually point (never understood why it would end in a point because by then the cars would have been almost totally derailed anyway).
Probably because trains ran in both directions on the bridge so either end could be the beginning of the guard rails. Coming to a point, the guard rails would most likely keep the wheel sets parallel to the track.
Mark
Use the next smaller size of rail for the guard rails. Code 0 guard rail for 83 mainline. I like to use the extended guard rails as additional bridge anchoring. I do this by spiking/ CAing those rails to the approach to the bridge abutment.
Modeling B&O- Chessie Bob K. www.ssmrc.org
The "gremlins" must be hard at work today. Couldn't edit or delete my previous post.
Those rails should be "CODE 70" not "0"
I won't allow the guard rails to touch. This will prevent any unwanted shorting on the bridge itself.
On the section of line I model, I measured two bridges roughly 10 miles apart and they both had the guard rail starting at 60 feet from the bridge. Hope this helps.
Nate
Which railroad is that, Nate?
Reason I ask is that different railroads have different standards. Some only install guardrails on through bridges, where a derailed car might damage the bridge structure. Others use them on everything that is more than a few centimeters above the surrounding area. A few didn't use them at all.
In Japan, where really tight radii are not uncommon, I've seen guardrails (at flangeway clearance) carried all the way through the curve, on the inner rail only. The object seemed to be to take the stress off the outer rail by bringing the inner wheel flanges into play.
I have also walked through an out-of-service tunnel which had guard rails full-length. At one end they extended on across a beautiful concrete spandrel arch bridge on a curve - a fine piece of engineering for a line which was built to support construction of a dam and was taken out of service (but not pulled up) after the dam was completed. (I suspect the guard rails continued through the tunnel at the other end of the bridge, but didn't cross it to find out. That tunnel ended in an active yard.)
Check on-line for the bridge standards of your prototype railroad. They might prove informative.
Chuck (Modeling Central Japan in September, 1964 - with lots of bridges and tunnels, all with guard rails)
I looked this up in the ATSF system standards vol 1. ATSF standard was 45' from point to bridge. I also found some other interesting stuff that you may also find interesting. Please enjoy this daily dose of useless information.
The General manager had the option of extending guard rails up to 300'
The points were # 10 frog points.
Guard rails are spaced 10" on center away from main rail. (I'm not sure how this compares to NMRA)
The guard rail begins to taper inward 1'-8" away from the bridge.
Using the same weight of rail for the track and the guard was acceptable. (good because I don't want to order more rail)
The front of the point is beveled at 45 degrees (relative to the horizon)
No tie plates are used beneath the guard rail.
On double track mains that had dedicated directions of traffic (like a highway), points were only required on the leading end of the guard (before the bridge). The unpointed end of the guard rails (after the bridge) ended 10' after the bridge without any bends.... never heard of this before. I wonder if this ever existed outside the standards,
Check out the Deming Sub by clicking on the pics:
I have a section of N scale ME bridge flex track that comes with two loose pieces of smaller code guard rail. Is there a preferred adhesive to use to hold these guard rails in place when installing them? Any tricks to simplify the installation?
Thanks,
Bob
CA works for a quick bond, however, Pliobond is a great alternative. It produces a very stong yet flexable bond.
Here's the CN bridge at 20 Mile Creek, on the Grimsby Subdivision:
Wayne
The railroad I am modeling is the Missouri Pacific. The bridges were installed in the 60's so I would imagine the 60 feet was the standard for the railroad at that time.
The PRR had a standard for everything.
http://prr.railfan.net/standards/standards.cgi?plan=71791-A
http://prr.railfan.net/standards/standards.cgi?plan=71790-A
http://prr.railfan.net/standards/standards.cgi?plan=61324-D
http://prr.railfan.net/standards/standards.cgi?plan=54343-A
Pete
I pray every day I break even, Cause I can really use the money!
I started with nothing and still have most of it left!
I may be wrong here, but with all my poking around in the wilds of western Canada exploring rail lines (especially C.P. ) I've noticed that
1. Guard rails seem to be old used rail that has been torn up through regular maintenance.
2. The distance from the end of the bridge to where the guard rails end depends on how long the piece of rail was when they pulled it off the car.
3. The ends of the guard rails are often different lengths. Sometimes by several feet.
When miles from civilization the railroads don't seem to worried about appearance just as long as the purpose is served. Nearer urban areas things definitely get neater and tidier including guard rails that are cut to the same length.
Brent
"All of the world's problems are the result of the difference between how we think and how the world works."