Bridge track

Deemiorgos,

Search on "Bridge Track" on Google.

I think it will answer your questions.

how they should be placed on my 50's bridge?

Hi Dee,  The 1950s era bridge rails I recall seem to have been a bit closer to the running rails ( but not as close as turnout guard rails are) than that photo but it might just be local practice. You might be able to find some 50s era CN bridge photos and see if the guard rails are visible. ...DaveB

Short answer

HI Dee,

My short answer in that if your bridge/guard rails are between the running rails then

1. they should be far enough inboard of the running rails to trap the full width of a derailed wheel.
2. they should not be the that far away from the running rails that would allow the outside of the rail vehicle on the side were the derailed wheels are outside of the running rails to contact the side of the bridge structure. Any impact to the side of the bridge structure by a derailed might weaken the bridge enough to cause its structural failure and collapse. 

I just checked one of our local (Australian) standards - It gives the distance between the inside rail face of the running rail and the rail face of the guard rail as 380 mm or about 3 to 4 mm between the railheads for HO model track.

Do a quick check of the thickness on a couple of your model wheels. The gap should be wide enough to allow your model wheels to fall into the gap and become trapped between the running rails and the bridge guard rail, thus preventing the other side of the derailed vehicle from wiping out your bridge.

You are off to a great start with your bridge, keep up the good work,

Not to hijack this thread...

...but HOW or WHAT IS the best way to glue that guard rail, keeping proper spacing, and not ending up with a huge mess.  I have made several attempts gluing the guard rails and I ruined 6 pieces of that Micro Engineering flex track.  Although it's a great deal more expensive, I am thinking of just buying the sections of bridge track from Walthers, but then all my bridges would have to be straight.

Thanks for indulging me.  

Ken L

making bridge guard rail

An alternative to glue that might work better would be to spike down the middle rails, if what's underneath them can accept spikes.

For myself, I'd do the whole thing the fast-tracks way with soldered PCB ties every inch or so. I'd do all the soldering at the work bench to make a bridge-length section of track with 4 rails and spaced out PCB ties, then lay wooden ties on the bridge in between where the pcb ties will go and the rails and pcb ties on top. This would enable a really nice look with the bridge ties spaced together closer than the non-bridge ties or different-sized bridge ties if either of those are prototypical for your era.

I'd build the bridge track straight, and then 'flex' it when laying it down. 

You can get a 'straight track' fixture from fast tracks, but it's probably not that helpful, as their stock straight one won't have slots for the guard rails. So if you had the fixture, you could only solder 2 rails, then you'd have to solder the guard rails in between, which is going to be harder than working far side to near side. 

Guardrail

The purpose of the guardrail is to keep the wheels from running off the ends of the ties or getting into the structure.

Put a wheel set on the track with one flange on near the end of the tie.  The other flange is where the guardrail should go (or actually that's the furthest from the running rail, it can go closer).

With the ballasted deck bridge, the object is to keep the wheel from running off the edge of the ballasted deck, since that's wider than the ties, the guard rails can be further from the running rail.

I'd build the bridge track

Not if it's soldered to each PC tie in 4 places, you won't. There's a reason flex track has one rail rigidly attached to the ties, and the other is allowed to slip...

If you're going to pre-build the track like that, bend the rail first then solder to the ties.

Guard Rails

It's been my observation that if a derailed car can hit the bridge girder or truss of a bridge, yes.  If it can't no.  Railroads don't seem to care if a car can derail off a bridge just as long as there is no potential damage to the bridge its self. 

So for your bridge you need guardrails.

Not if it's soldered to each

Oh, uh, yeah. I'd probably have figured that out on my own after I built one or two, lol. 

Yours is a ballasted deck thru girder

So you can have the guard rails closer together as in the picture above.  The basic rule still applies.  They should keep a derailed car from shifting laterally and hitting the girders.

Scott Chatfield 

Thank you all for your

Thank you all for your replies. Sorry for the delay; busy bee here with the Thanksgiving long weekend.

I found some code 55 rail.

Not measuring yet; just placing it to test fit it. 

Pliobond?

Just curious but I seem to recall a number of folks using Pliobond to glue rail down to plastic ties?

Brian, I have used Pilobond

Brian,

I have used Pilobond in the past and it worked and held up over the years.

Not measuring yet; just placing it to test fit it.

Hi Dee, Looks great, nail it down!   :> ) ....DaveB

DaveB, thanks. But I'm going

DaveB, thanks. 

But I'm going to set them aside for now, as I have to secure the track to the bridge and do some tweaking.

I have made some spacers for when the time comes to glue them in.

1939 Best Practices for Guardrails

Hi Deemiorgos

I know you have progressed past this point, but I wanted to put this out here for future reference. 

From my 1939 Railway Engineering and Maintenance Cyclopedia:

• Guard rails are "removed a sufficient distance (from the running rails) to provide a path for the derailed wheels"
• The rail is "a single line of old rail of no greater but generally a lighter section than the main rail and set 8 in. or 10 in. inwardly therefrom."
• Timber guard rails (outside of the rails): "It is recommended as good practice to use guard timbers on all open-floor bridges. They should be so constructed as to properly space the tie and hold them securely in the places"
• "It is recommended that the guard timber and the inner guard rail, when used, be so spaced in reference to the track rail the a derailed wheel will strike the inner guard rail without striking the guard timber. The inner guard rail should not be higher or over 1 in. lower than the running rail." 
• "It is recommended as good practice to extend guard rails beyond the ends of the bridges for such distance as is required by local conditions but not less than 50 ft."

After some words about how to bend the ends of the guard rail together:

• "It is recommended as good practice to use inner guard rails on all open-floor and on the outside tracks of all solid -floor bridges and similar structures longer than 20 ft. in main-line tracks, and on similar bridges and structures in bran cline tracks on which the speed of train is 20 miles per hour or more."

Matt, Very informative. I was

Matt,

Very informative.

I was just winging it, and now I have a good idea.

My rails about 14 inches inward from the rail and the extended guard rails are only 25 feet beyond the edge of the bridge. None of it has been glued down and I have more code 55 rail.

I'm guessing the extended rail is that way because it is the average length of a freight car?

I have seen some prototypes with shorter extended guard rail, but are modern scenes.

Commerical Bridge Track, or mk my own?

Several months ago I was trying to figure out what I wanted to do for guard/safety rails on my entranceway bridges. I had commercial build Shinohara bridge track, and thought about making my own. Here's a link to those pics,..

https://forum.mrhmag.com/post/safetyguard-rails-on-bridge-tracks-12217299

Here I am again!...

Get ready to laugh at me. Why not use DAP Alex caulk to "glue" the guard rails in place? Since I used it to glue the track to the roadbed, both plastic, and there's no damage to PECO ties. Unless ME has some "other" plastic. Or whatever track is used. I've gotten used to using that caulk for several places. It may not be permanent, but does hold sufficiently. My track and roadbed have been in use long enough to assure me, so I have to assume that gluing guard rails would be no problem. The other thought from me is that as you know, I am not in favor of permanence. I like to be ready to change things or repair them or move them around. ?? I might add, using caulk is a lot less messy than any glue. Especially Gorilla. I find that stuff a little "iffy" when I use it. For one thing, you have to hold the items very steady for a long time before Gorilla sets. And IMHO this caulk is cheap enough to satisfy this old frugal 82 yr old getting to 83/around the corner.

@Brian, I recall that thread

@Brian,

I recall that thread and posted a pic on it. I'll check out the link to see what is new.

@Morgan,Holy mackerel!

@Morgan,

Holy mackerel! You're old enough to remember steam locos and bobby socks.

I am going to experiment with various adhesives on a piece of track. Peco code 70 is on this module.

I am using ME code 55 for the guard rails.

@Brian,

I recall that thread and posted a pic on it. I'll check out the link to see what is new.

That sounds like...

ME rail on PECO plastic ties. The caulk should work just fine. I know you probably still have some DAP Alex still around. Try it! And what I said about it would be ideal. If that don't look right, you will be able to pry it up and relay and re-caulk. With no damage to either the rail or the ties. And when you are finally sure everything is just right, you can leave it alone. The caulk will hold those rails for a long time.

Morgan,Will start

Morgan,

Will start experimenting; hopefully this week. I'll keep you posted.

Spiked Guardrail