prototype railroads use guard rails to keep derailed equipment from falling off bridges and trestles.
How effective are guard rails on model trestles?
greg - Philadelphia & Reading / Reading
I installed them because I think they add realism to the track structure. I don't believe I've noticed any difference in keeping equipment within the boundaries of the guard rails during a derailment. It may help a little but probably not to a degree that could be easily quantified.
PRR_EF-15_2_tone by Edmund, on Flickr
IMG_2589 by Edmund, on Flickr
That could bring up a good point though, to study and quantify the root causes of derailments. I'd have to keep a log book handy. I'll bet 75% of mine are due to running through switches that I've forgotten to realign.
Regards, Ed
My last two layouts did not get far enough to recieve guardrails.
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I did not use them in N scale in the 1980s because code 55 rail was not readily available in hobby shops. I remember trying to use brass bar, but it did not work out.
When added, they certainly make a bridge look better, but I doubt they do very much to keep equipment on the bridge.
My understanding on through truss bridges the guardrails were more for protecting the bridge than the equipment.
My current bridge project came with guard rails installed, although they end way to close to the bridge to actually be any good. These are just for looks.
-Kevin
Living the dream.
gmpullmanThat could bring up a good point though, to study and quantify the root causes of derailments. I'd have to keep a log book handy. I'll bet 75% of mine are due to running through switches that I've forgotten to realign.
I'd say about 99% of mine are my fault with the turnouts being set incorrectly.
York1 John
I am meticulous about my trackwork and will spend hours fixing track defects that lead to repeatable derailments. With a limited number of pieces of well-maintained engines and rolling stock, my bridges never have issues, so the guardrails are completely for show.
But, like the close ties of bridge track, I think they add a lot to the appearance and realism of the bridge.
This is a simple trestle I built by removing the ties from some flex track, cutting the spacers on the tie strip, and then replacing the ties with much closer spacing. Then, I took some rail sections, bent them, weathered them and glued them to the ties with CA. I think it really improved the look of the trestle.
It takes an iron man to play with a toy iron horse.
gregc prototype railroads use guard rails to keep derailed equipment from falling off bridges and trestles. How effective are guard rails on model trestles?
ROAR
The Route of the Broadway Lion The Largest Subway Layout in North Dakota.
Here there be cats. LIONS with CAMERAS
just below the table two modules are connected with a narrow arced span.
would guard rails keep cars from falling off the span if they derailed?
I think guard rails look awesome in model bridges, but I don’t think they really do anything. I think the issue is that model trains are a lot lighter. Are guard rails even ment to stop derailment, or keep trains on the bridge when they derail? I’m not sure I even know the answer...
The point is I don’t think guard rails really help in model train derailments, a better bet would be a plexiglass pane on the layout facia (which I think the OPs picture has).
Regards, Isaac
I model my railroad and you model yours! I model my way and you model yours!
SPSOT fan Are guard rails even ment to stop derailment, or keep trains on the bridge when they derail?
guard aren't intended to prevent derailments. They trap the inside wheel between the guard rail and rail to keep the wheels on the ties.
SPSOT fana better bet would be a plexiglass pane
looking to avoid using a panel.
gregc SPSOT fan Are guard rails even ment to stop derailment, or keep trains on the bridge when they derail? guard aren't intended to prevent derailments. They trap the inside wheel between the guard rail and rail to keep the wheels on the ties. SPSOT fan a better bet would be a plexiglass pane looking to avoid using a panel.
SPSOT fan a better bet would be a plexiglass pane
Yeah my first though was guard rail keep the trains on the track, then I second guessed myself...
I understand not wanting to use a panel, they are very ugly and are hard to see through and get dirty and you can fill in the rest.
My grandpa has had a layout in his garage for years now with a track about an inch from the edge of the layout with a 5 and half foot drop to the floor. We’ve had people (including be when I was younger...) run trains at speed step 99 and had no issues. The derailment it that track have been few (I can’t even remember one, though I’m sure it has happened in the past 12 or so years) and never included anything falling.
Now this is an area with no curves or turnouts. Those are the main derailment causes I know of. So if you use only straight track on a lift out bridge or such you should be fine. If you are worried or just wan to be extra safe add an inch and a half to each side and nothing should be capable of falling.
As Greg has correctly noted, the guardrails keep the derailed wheels from wandering sideways, where they might allow the car to strike parts of a through-bridge's structure, or, on an open bridge, overturn and roll off the bridge completely.
This photo illustrates the ineffectiveness of the guard rails on the high bridge in the background...
...and it seems that a low coupler was the culprit, rather than a simple derailment, catching on something (perhaps the ties or even the guardrail itself) and causing the train to partially stringline (the locomotives and some cars, uphill from the derailment, and a longer portion of the back end of the train did remain on the tracks.
On our modelled bridges, the guardrails and closely-spaced ties do contribute to the authentic look...
Wayne
doctorwayne As Greg has correctly noted, the guardrails keep the derailed wheels from wandering sideways, where they might allow the car to strike parts of a through-bridge's structure, or, on an open bridge, overturn and roll off the bridge completely. This photo illustrates the ineffectiveness of the guard rails on the high bridge in the background... ...and it seems that a low coupler was the culprit, rather than a simple derailment, catching on something (perhaps the ties or even the guardrail itself) and causing the train to partially stringline
...and it seems that a low coupler was the culprit, rather than a simple derailment, catching on something (perhaps the ties or even the guardrail itself) and causing the train to partially stringline
Given what we have learned in Build a Club Layout thread, during a derailment, some operators are not paying any attention at all.
The Youtube videos I've seen of real derailments indicate the engineer would feel or hear something when trains start to derail and fall over one another.
Henry
COB Potomac & Northern
Shenandoah Valley
BigDaddy...Given what we have learned in Build a Club Layout thread, during a derailment, some operators are not paying any attention at all....
Yeah, you might think that from the apparent carnage. The train involved was fairly long...it might have been in excess of 70 cars, and for such trains, multiple locomotives are necessary. Since the track being used was one shown in the "How close to the edge...?" thread, I always walk alongside the locomotives, in case one of them derails. The train was still moving, albeit slowing, when the cars derailed. It was fairly easy to repair the cars, while locomotives would likely have been a bit more work. So I was paying attention, at least to the most expensive part of the train.
My most usual derailments are caused by running through an improperly-aligned turnout....somewhat embarrassing, since I'm almost always walking alongside the train and my turnouts are manually controlled.
doctorwayne...and it seems that a low coupler was the culprit, rather than a simple derailment, catching on something (perhaps the ties or even the guardrail itself) and causing the train to partially stringline (the locomotives and some cars, uphill from the derailment, and a longer portion of the back end of the train did remain on the tracks.
seems that curved bridges are not a good idea considering string lining.
maybe guard rails would have been good enough to prevent anything falling on a straight bridge even if something snagged
gregcseems that curved bridges are not a good idea considering string lining.....
I'd guess that at least half of my mainline is on curves, and that incident on the bridge is the only time I've experienced stringlining on this layout. There are six bridges on the layout, all of them with guardrails and all of them on curves.
RR_Mel ...When I went with the guard rails it wasn’t to really prevent a derailed car from hitting the deck it was for realism....
Like Mel, I added them for realism. There are many other places on my layout where a derailment could result in serious damage , guardrails-or-not, but that incident on the bridge was definitely caused by a low coupler. Dozens of long trains have used those bridges, with only that one incident of stringlining.
As I mentioned, my most frequent derailments are very minor, and caused by running through improperly aligned turnouts - definitely operator error.
i understand that curved bridges and trestles on layouts are often unavoidable and that derailments on them may be rare. Makes me wonder if bridge derailments are similarly rare on the prototype? if so, why add guard rails (law)?
in my case, I'm considering building modules connected by unsupported (splined) spans, similar to that in the image above. I'd like to avoid building walls on either side of the span to protect equipment from falling and wondering if guards would be "good enough".
based on comments, derailments should be rare and guard rails would be good enough, if not unnecessary. A wall may only be needed on the inside of curved spans.
gregc I'm considering building modules connected by unsupported (splined) spans
If you really want to avoid equipment from falling, you need an ugly plexiglass wall.
Or... you can roll the dice, but snake eyes always come up eventually.
Just to be clear here, are we talking about ''Guard Rails'' or ''Guide Rails"? I guess we could use both words for the same piece of rail that sits along the inside of the main rail could we not? No Bridges here are without these two second set of inner rails. If something bad happens, I don't want a rail car taking out a Bridge.
in the image, there are 4 rails. aren't the 2 inside rails called guard rails? the certainly aren't guiding the wheel unless it's derailed.
On the prototype, the goal of guard rails is not to prevent derailments. The goal is to keep minor derailments from becoming catastrophic crashes with equipment jamed in the bridge structure or from leaving trestles or other deck bridges.
A single derailed axle can be drug along for miles, but the closer clearances of a bridge are likely to snag that car.
The guard rail keeps the derailed inside wheel close to the rail, keeping the car within the clearances of the bridge structure. This will generally also prevent cars from leaving trestles or open bridges.
The beginning of the guard rail is curved into the center to grab and steer any such derailed wheelset and pull it over near the rail.
Their effectiveness on our models is likely not quite what it is on the prototype, but surely they can't hurt.
Sheldon
Maybe they ''Guard'' against derailments first then if there is a derailment, they ''Guide'' the wheels to stay parallel to the track.
Edit; Ok I see you just kinda said what I just typed slower. That keeping the wheels parallel (between the main and this second rail) is a good thing for the ''Wrecking Crew".
PC101 Maybe they ''Guard'' against derailments first then if there is a derailment, they ''Guide'' the wheels to stay parallel to the track.
I've been around trains and model trains for 50 years, never heard them called guide rails by anyone? At least not in North America?
Don't know what they call them elsewhere.......
Ok, ''Guard'' Rails it is. Thank you.
I have to attest to the the fact that even on our layouts, GUARD RAILS DO IN FACT WORK. I model in N scale, so even the smallest irregularity, bend or twist in track, or sudden increase or decrease in track level can cause a car to derail. I have 2 examples:
I recently moved and in doing so, my layout got a little beat up in the process. I have a small section of track right after a crossing on a curve. Never had the problem before, but cars kept derailing after I moved and set up my layout again. after thorough inspection, I determined that the track somehow twisted, resulting in one rail being about 2mm higher than the paralell rail on the other side. I use low profile metal wheels, and they kept jumping track. If I were to remove this section of track and replace it, it would just be a mess due to the surrounding crossings, turnouts and road grade crossing. instead, I cut a small section of track with the same curve radius and positioned it on the inside rail where the wheels kept jumping... guess what? No more derailing. it doesnt look very prototypical, but it is such a small section of track, no one has yet to notice. Plus, it was a very cost efficient solution and saved me countless hours, money and headaches of repair construction.
20190914_234230 by John Collins, on Flickr
Second Example is on a custom built curved trestle. There is a spot on the curve that was just slightly too tight of radius for my 2-8-0 steam loco. the engine would not completly derail, but the first pair of "8" wheels would jump off the track around the curve and eventually re-rail themselves when the curve straightened out. This made me nervous because if a train went off here, it was a 4 foot drop straight down to the floor. I didnt want to rip out my custom bridge and start over, I had already put in too much time and money. I decided to try the guard rail along the inside curve.... now the 2-8-0 negotiates the curve effortlessly and all the wheels stay onthe track. I will eventually add a second guard rail to increase the realism and prototypical look, but I am concerned it may create a "pinch point" on the curve for the steam loco... I will let you know.
20190914_234530 by John Collins, on Flickr
-John Collins
guard rails are essential on the diverging path of turnouts to "guide" wheels across frogs
gregc guard rails are essential on the diverging path of turnouts to "guide" wheels across frogs
Yes, but turnout guard rails, or crossing guard rails are set closer to the running rail and are just as high as the running rail, to put the flange in a very specific spot relative to the track guage by interacting with the back of the flange.
A bridge guard rail is purposely lower and farther away to not have any interaction with the wheel unless the wheel is derailed.
The friction/interaction of a whole line of cars the length of a bridge running thru turnout grade guard rails would be a problem both in terms of wear on the wheels and rail as well as needed power to move the train.
Nice-looking layout, John!
irishRR...I cut a small section of track with the same curve radius and positioned it on the inside rail where the wheels kept jumping... guess what? No more derailing. it doesnt look very prototypical, but it is such a small section of track, no one has yet to notice....
I had a similar issue on the partial upper level of my layout, where locomotives with longer driving-wheel bases would sometimes have their pilot truck wheels derail when approaching the point-end of a curved Shinohara turnout. A same-code (83) guardrail on the inside rail of the curve (Atlas flex track) approaching the turnout, solved the problem. It's spaced from the inside rail similar to the placement of a normal guardrail, mainly governed by the moulded-on spike heads of the Atlas track. I doubt that many observers would even notice its presence.