# Custom-building guard Rails for bridges



## Overkast

Hi all, I have an N Scale layout with 4 bridge structures, all will be custom-built, and some (or all) of which I would like to build guard rails into their designs. Has anyone done this themselves that can give me some advice on how to go about it? One of the bridges will have curves, so that would be an extra challenge.

Here's a diagram I drew to show an idea I have in my head, of how I might achieve this... For the gaps, I would need a material that is both thick and flexible (to follow the contours on the curved bridge), which I can also get in different thicknesses. Styrene is the first thing that comes to mind:








My idea involves taking the guard rails and butting them up against the edge of the inside rail fasteners on the sleepers, and then filling the gaps with various sheets of styrene. Your thoughts?


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## Mark VerMurlen

This looks like a sound plan to me. One potential problem might be getting the center spacer to bend properly around your curves since it will be much wider than your narrower side spacers, so its not going to want to bend easily. Do you think you'll really need the center spacer? Could you leave it out and use pins to hold the guard rail in place against the side spacers?

The guard rails should be one code size smaller than your main rail. I'm not sure what the code sizes are for N scale, but for HO if your main track in code 100, you want the guard rails to be code 83. That will keep the guard rail below the height of your main track and references I've seen suggest that's what the prototype does too.

Mark


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## Overkast

Really great feedback Mark, thanks very much. I hadn't thought of the thickness of the center styrene being an issue around curves, I reckon you may be right about that. I planned on mounting the track to a piece of tempered hardboard (cut to shape), so I'm not sure how well pins will go into hardboard and hold - I'll test that.

Regarding the track code, I am already doing Code 55 which is the the smallest N Scale, so I'll have to deal with the lack of replica authenticity. But it's such a small scale I'm ok with that anyway. Really just going for aesthetics on this anyway. 

One other question - I want to use a strong glue that I can put on finely without making a total mess, and something that will dry crystal clear. Elmers won't cut it - too messy / dries with a white haze / and I'm not confident it has the bond I'm looking for either. Any recommendations?


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## Mark VerMurlen

On my layout, I used a gel CA adhesive. I think CA adhesive is the same thing as "Super Glue". Super Glue is normally quite thin, but they now make a gel version. I used the LocTite brand. You can find it at Home Depot and Lowes as well as hobby shops. The gel variety is nice in that it will come out as a small bead that will stay in place on top of the tie. I then was able to press and hold the guard rail in place for a few seconds as it set. I actually didn't need to hold the guard rail in place with anything but my fingers since my track had small dimples to help locate the guard rail. It was enough to just feel the rail sit down between the dimples and wait for the glue to set. You may find that you need just a short section of the spacer material to put between your main and guard rails to get the right gap that you then move along as you glue the guard rail down. Since the CA sets fairly fast, you don't need to keep pressure on it for long. Just be careful not to glue your fingers or the spacer to either rail. I would suggest giving it a try on some scrap track to see what works best for you.

Mark


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## wingnut163

you do not need to go to all that just for guard rails. take a section (36") of track and pull the ties off. on the straight bridges cut two pieces two inches longer. lay one on the in side up against the fish plates. that will give you enough space for clearance. same on the other side. these can be spiked in the same as the running rail.
for the curve, its not that much different. the rail will curve with a little pressure in your hand. then do the same as the straight bridge. a pair of pliers will bend the ends in at the start of the bridge.
good luck and let us know (with pictures) how it all came out.


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## Overkast

Thanks again Mark, I'll look into the CA adhesive.



wingnut163 said:


> you do not need to go to all that just for guard rails. take a section (36") of track and pull the ties off. on the straight bridges cut two pieces two inches longer. lay one on the in side up against the fish plates. that will give you enough space for clearance. same on the other side. these can be spiked in the same as the running rail.
> for the curve, its not that much different. the rail will curve with a little pressure in your hand. then do the same as the straight bridge. a pair of pliers will bend the ends in at the start of the bridge.
> good luck and let us know (with pictures) how it all came out.


wingnut, I'm not sure I'm entirely following you - When you say fish plates are you referring to the rail fasteners that hold the rails in place? Because a real-life fish plate is the equivalent of a rail joiner in modeling...

Fish plate:








Rail fasteners:








And not sure I understand fully what you're describing here as well. If I'm pulling the rails out of a 36" section of flex track and putting those rails up against the rail fasteners, then that is precisely what I'm suggesting to do in the diagram (the guard rails in the diagram would be removed from a section of flex track).

I realize now I didn't mention that originally, but a spare piece of flex track is exactly where I planned on getting the "extra" rails.


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## DonR

I don't see a 'fish plate' in either of your two pics.

Here is what I recognize as a 'fish plate':

https://en.wikipedia.org/wiki/Rail_fastening_system

A fish plate is a square casting that sits under the
rail. The spikes are driven through holes in it.

You can see them under the rails in typical flex
track molded to the ties.
You would abut these with your guard
rail bottom flange
and the flangeway would work out fine.

Don


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## Overkast

Hi Don, since you're referencing wikipedia, here is where they also refer to my image as a fishplate: https://en.m.wikipedia.org/wiki/Fishplate 

Thanks for the clarification though, it seems to be a matter of terminology causing the confusion on my end since it seems We're talking about the same technique.

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## jargonlet

I may be wrong because it is late at night but it seems like you are just wanting to add guard rails and then maybe fill in the inside between the rails. Micro Engineering makes bridge track with wider ties and guard rails. The guard rails are code 40 and the main rails are code 55.


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## Overkast

jargonlet said:


> I may be wrong because it is late at night but it seems like you are just wanting to add guard rails and then maybe fill in the inside between the rails. Micro Engineering makes bridge track with wider ties and guard rails. The guard rails are code 40 and the main rails are code 55.


jargonlet, you just saved me a ton of work and possible headache!!! I had no idea there was a bridge track flex track in code 55 out there. Thank you so much! I just looked it up and it's perfect. 

Also I wasn't looking to fill up the space between guard rails, just using something to keep them spaced evenly while drying.

Much appreciated!

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## CTValleyRR

Overkast said:


> Hi Don, since you're referencing wikipedia, here is where they also refer to my image as a fishplate: https://en.m.wikipedia.org/wiki/Fishplate
> 
> Thanks for the clarification though, it seems to be a matter of terminology causing the confusion on my end since it seems We're talking about the same technique.
> 
> Sent from my SM-N910V using Tapatalk


Not really terminology, but dialect. The way you use the term is the British usage, Don is using the American.

"The British and Americans are two peoples separated by a common language." -- George Bernard Shaw.


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## Mark VerMurlen

Hey Overkast, I'm curious to know how your bridge project is going. Any update you can give?

Mark


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## Overkast

Hey Mark, sure thing I'd be happy to give an update. So my progress has been a bit slow... being that this is new territory for me, I am kind of formulating a process as I go and have had a few lessons learned along the way.

I've decided I'm only going to scratch build 3 of the bridges on my layout, because the 4th one is right along the edge of the table and I'm a bit nervous about derailments causing a train to fall right off my table from that bridge, so i decided I'm going to buy a truss bridge to protect trains on the edge of the layout there.

Here's a pic that shows those 3 bridges I cut using 3/4" thick MDF board, and I plan on mounting the styrene plate girders I'm building to the sides of them:








The 2 bridges in the foreground are straight bridges and should be fairly easy to do, but the long bridge in the background is 34" long and has 2 curves (one on each end), and that one's going to be more challenging. So I'm doing this first build / test on one of those straight bridges in the foreground.

Here are the 2 completed side panel plate girders for the first bridge:








I am using 1/8" thick styrene for the side panels and 0.015 styrene for the girder ribs. 

It took me a while to get to this point, because originally I was mistaken that a Woodland Scenics foam product I bought was the equivalent of a "styrene", but it was not - it was a soft foam and I quickly discovered when trying to super glue the first rib that the glue melted / destroyed this foam:








So I had to order some official Evergreen styrene and then wait for it to ship to me to re-do.

Now that I've finished the plate girders for one of the bridges, I've finally ordered some Micro Engineering Bridge Track, and that will be delivered this week. I need to wait for the Bridge Track to be delivered before I can move this further along, because when I put the plate girders up next to the MDF piece, the bridge looks too thick when I use a regular piece of Code 55 track:








As you can see the track ties don't overhang off the edge, so before I do anything I want to get the Bridge Track because I know the ties are wider, and I want to see what the overhang looks like with that track.

If the MDF proves to be too thick even with the ME Bridge Track, my "Plan B" is to just use 1 more piece of 1/8" styrene between the 2 plate girders and it should work out fine (albeit just for 2 straight bridges):









The long curved bridge will be a different story, because I need to use the MDF piece to retain the specific shape of that bridge:








So my "Plan B" for that bridge is, instead of using the 1/8" thick styrene for the plate girder sides, I might just use the thin 0.015 styrene as "sides" and super glue the ribs to those.


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## Mark VerMurlen

Wow! You've got a very ambitious project going on there. It looks great thus far. Looking forward to seeing the end product.

Mark


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## Overkast

Well, got the ME Bridge Track today and definitely not going to be doing both the MDF and styrene... so now I'm on the fence on whether I'm going to do 2 pieces of styrene in between (less tie overhang) or just 1 piece of styrene (more tie overhang). Any thoughts?

2 pieces between:









1 piece between:









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## Mark VerMurlen

If it were my decision, I'd go with 2.

Mark


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## Overkast

Mark, I think you're probably right. Looking again at some prototype deck girder bridges today, and I think the 2 pieces of styrene in the middle gives about the same width / overhang as the prototypes:


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## Lemonhawk

I think the overhang is the way to go. On the real bridge the track is on top girder, probably centered right on the top plate so the load goes right thru the tie and on to the girder with no stress other than compression on the tie. It looks scary in real life, on your model it will be even worse as its your engine that looks like it might fall off! You'll notice on the real bridge that they saved some money by not putting in guard rails! The bridge ties you have also may have stringers along the outside, another feature missing on the real model! Bridges really make the layout have that wow factor! Keep it up!


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## Overkast

Exciting update! I finished the plate structure of my first deck girder bridge. I did 2 pieces of styrene in the middle and am very happy with the results. Added a bottom rib and sanded everything down so it's all flush. Can't wait to start painting this thing!!!

















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## Lemonhawk

Nice looking really long bridge. Did you fill in between the outside girders for strength? You could add a top plate (like your bottom "rib") to each girder and have the bridge ties set on that to give that more open look. Paint the middle filler a deep black and weather the girder to make it stand out. I think the 2 styrene girders alone with just a few cross braces would be strong enough. Make everything open and scary looking. Great project! :appl:


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## Overkast

Thanks Lemonhawk. Yeah I filled in the middle space with styrene for both strength purposes and for ease of making consistent width throughout the entire span. I'm not too concerned with exactness of prototyping (like open space between girder plates), I'm more concerned about maintaining a consistent structure integrity and having a "convincing enough" resemblance to the prototypes. I am planning on painting this bridge black and then using weathering techniques to create rust on the sides. I might also experiment with the standing platforms that come with the ME Bridge Track too, but I'm thinking maybe not on these 2 smaller bridges but definitely on the longer 34" bridge with curves (I don't want redundancy in all the bridge looks).

Now that all the styrene is glued together this bridge feels like a significantly sturdy structure all on its own... I don't even need bridge piers if I didn't want them!! (But I do) 

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## Lemonhawk

Yes, by the time you get all the vertical ribs along with the top and bottom plates, you have a real girder! Looking at the prototype, the curved part is really straight segments between piers, so you need the piers, even if the model does not structurally need them. Also keep in mind that you can attach the piers to the bottom of the bridge then groom the terrain below to meet the piers which really do not need to be mounted to the terrain. Clutter some bushes around the bottom of the pier to hide the interface. You can put a lot of character into the piers!


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## Overkast

Lemonhawk said:


> Looking at the prototype, the curved part is really straight segments between piers, so you need the piers, even if the model does not structurally need them.


Yeah, I noticed that too... yet another aspect of my models that isn't true to prototype. I really didn't feel like designing the bridge curves as straight segments and having to cut the MDF board that way, so I opted for smooth, continuous curves instead. I'm confident the plate girders will still look nice along a curved surface, even if it's not prototypical. 

Also, there are usually extra "ribs" at the ends of plate girder sections where they meet each other (usually at every pier). I didn't do that currently, but I'm pondering doing it before I actually paint this bridge. It's not a lot of work to add a few more, and it could give the bridge a nice little bit of extra detail...


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## Lemonhawk

I think on the prototype each girder was the span between the piers, which made it easier to use straight sections to make the curve. Now days the typical girder joint is about 1/3 the distance from the pier where the stress is the least. But that does not work very well when the bridge is curved. The bridge ties I have from Walthers do not bend and the actual tie structure on top of the girders would be a nice curve. I'm an Electrical Engineer (retired) but when I was in grade school my Civil Engineer father worked on some big bridges, so I spent a lot of time in summers going to work with him. I had no business walking girders without any safety harness, but that's the way it was done back then. When young your fearless. It was fascinating watching them throw hot rivets and assemble a bridge.


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## Overkast

Not a ton of progress to report, as I'm now starting to experiment with paint colors for rail painting. But I did decide to go with the extra "ribs" on the bridge and I'm glad I did:









With bridge now spray-painted:


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## Lemonhawk

Yes the piers make it look realistic, Nice looking bridge! With three long bridges in the view it will be a real eye attractor!


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## peterincalgary

Overkast said:


> Hey Mark, sure thing I'd be happy to give an update. So my progress has been a bit slow... being that this is new territory for me, I am kind of formulating a process as I go and have had a few lessons learned along the way.
> 
> I've decided I'm only going to scratch build 3 of the bridges on my layout, because the 4th one is right along the edge of the table and I'm a bit nervous about derailments causing a train to fall right off my table from that bridge, so i decided I'm going to buy a truss bridge to protect trains on the edge of the layout there.
> 
> Here's a pic that shows those 3 bridges I cut using 3/4" thick MDF board, and I plan on mounting the styrene plate girders I'm building to the sides of them:
> 
> 
> 
> 
> 
> 
> 
> 
> The 2 bridges in the foreground are straight bridges and should be fairly easy to do, but the long bridge in the background is 34" long and has 2 curves (one on each end), and that one's going to be more challenging. So I'm doing this first build / test on one of those straight bridges in the foreground.
> 
> Here are the 2 completed
> 
> 
> Overkast said:
> 
> 
> 
> Exciting update! I finished the plate structure of my first deck girder bridge. I did 2 pieces of styrene in the middle and am very happy with the results. Added a bottom rib and sanded everything down so it's all flush. Can't wait to start painting this thing!!!
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> 
> Sent from my SM-N910V using Tapatalk
> 
> 
> 
> side panel plate girders for the first bridge:
> 
> 
> 
> 
> 
> 
> 
> 
> I am using 1/8" thick styrene for the side panels and 0.015 styrene for the girder ribs.
> 
> It took me a while to get to this point, because originally I was mistaken that a Woodland Scenics foam product I bought was the equivalent of a "styrene", but it was not - it was a soft foam and I quickly discovered when trying to super glue the first rib that the glue melted / destroyed this foam:
> 
> 
> 
> 
> 
> 
> 
> 
> So I had to order some official Evergreen styrene and then wait for it to ship to me to re-do.
> 
> Now that I've finished the plate girders for one of the bridges, I've finally ordered some Micro Engineering Bridge Track, and that will be delivered this week. I need to wait for the Bridge Track to be delivered before I can move this further along, because when I put the plate girders up next to the MDF piece, the bridge looks too thick when I use a regular piece of Code 55 track:
> 
> 
> 
> 
> 
> 
> 
> 
> As you can see the track ties don't overhang off the edge, so before I do anything I want to get the Bridge Track because I know the ties are wider, and I want to see what the overhang looks like with that track.
> 
> If the MDF proves to be too thick even with the ME Bridge Track, my "Plan B" is to just use 1 more piece of 1/8" styrene between the 2 plate girders and it should work out fine (albeit just for 2 straight bridges):
> 
> 
> 
> 
> 
> 
> 
> 
> 
> The long curved bridge will be a different story, because I need to use the MDF piece to retain the specific shape of that bridge:
> 
> 
> 
> 
> 
> 
> 
> 
> So my "Plan B" for that bridge is, instead of using the 1/8" thick styrene for the plate girder sides, I might just use the thin 0.015 styrene as "sides" and super glue the ribs to those.
Click to expand...


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## peterincalgary

Be careful of using MDF, I used some on a basement layout, unfortunatly the toilet plumbing sprung a leak 3 days before we returned from vacation, the MDF greatly expanded and had to be replaced, we had $35K damage on the main & basement, luckily covered by insurance, in regard to a post on Walthers bridge rail, I have the #948-83005 bridge rail ends code 83 all rail main & guard is Code 83, the bridge track is #948-83004.


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## kilowatt62

peterincalgary,

Just so you know sir, this thread your’e posting to is five and half years old. Aka; dead thread.
Cheers.


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## peterincalgary

Just thought other should know my experience with MDF, maybe others like yourself will check


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## Big Ed

peterincalgary said:


> Just thought other should know my experience with MDF, maybe others like yourself will check


MDF, good point, thanks for the info.
It would be easier to shut off the main valve on your water when you go away for vacation or a few days.
A lot of flooded basements are caused by a washer hose failing. For peace of mind install ball valves for the water lines and turn them off every time after using them.


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## peterincalgary

Yes we do that now, but hadn't before for 45 yrs living in Canada, what failed was the nut that connected the tubing on the tank


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