I’ve Googled and searched Model Railroader with no luck, but I might be using the wrong terms! How far would a cut in a hill (the face of the embankment) be from the center, closest rail, and/or ballast? Is there a standard, guideline, or whatever?
You guys always come through. Thanks for your help.
Count on about an inch and a quarter to be realistic for minimum side clearance to center-rail, particularly on curves that are under 24" radius. On tangent tracks, you can pare the clearance down to about 15/16" from track center, but only out of necessity, and not for realism. Watch for the cylinder saddles and cab roof extensions on steamers, though.
Crandell
Hi!
Not to be a smart alec, but the answer is typically “wide enough to let the train go through”.
The NHRA gauge gives us some excellent guidelines on this, so I would tend to use that if there was some tight spots. The thing is, the prototypes not only want to get their trains through safely, but also to give some extra room for stuff that might be hanging off the train. I also feel that there should be room for a man to get to safety, but I dont’ think that’s always the case.
On our layouts, I would run all our equipment through the gap, coupling long to short and long to long cars, and of course our tallest cars for the test trains - as well as ALL your locos. Oh, and if its a curve, you may want a little extra clearance on the outside as some cars/locos could lean.
Are we automatically assuming HO? OK.
For HO, that seems a little tight, given that the NMRA S-7 clearances guide for tangent (straight) track is 1 1/32".
For curves, broader clearances are needed, as can be derived from NMRA S-8. More like 1 1/4" to 1 1/2" might be necessary.
For long modern equipment, more might be necessary in curves. Those dimensions are for basic clearance. In real life, railroads usually provide more than the absolute minimum, so depending on the type of scene you are contemplating, another distance may be more appropriate.
Note that these are the NMRA standards – not sure what the NHRA would say … [:)]
The NMRA has a standard here http://nmra.org/standards/sandrp/pdf/s-7_2011_02.pdf that shows the clearance for different eras and scales as well as the prototype. Some additional info including some AAR plate diagrams http://www.nmra.org/standards/sandrp/gauge.html
Narrow gauge could be different.
Shortline railroads might never have had the money to upgrade so they could well have closer than normal clearances - especially those that started as narrow gauge lines.
Enjoy
Paul
Byron, agreed, they are tight, but they are possible when the need is great…as I stated. The NMRA Guidelines (modelled after the NHRA’s) are just that…guidelines. If realism is not so important, they are not minimums, just guidelines. Similarly, while they state that 3" of overhead HO clearance is suggested, I have gotten it down to a full half-inch below that with the result that only the tallest of caboose stacks and MOW heavy lift cranes can’t make it.
As we, as a group, always suggest to people asking these types of questions, there is no substitute for mocking it up and testing for oneself. I just did that two days ago for my helix ramp. I laid out two lengths of flex at my desired track center separation (2.75") on radii of 33 and 36"ish, and looked for trouble with my worst combination, the Rivarossi Allegheny and a Walthers 80’ passenger car. I watched for outboard and inboard clashes, and found that I was fine with 1.5" outboard from the rail centers in each case.
Crandell
OK, seems I wasn’t very clear in my question! Just for full disclosure, yes, I’m modeling in HO (Southern, early 1950’s, mostly freight). However, my real question was whether actual (prototype) railways had any guidelines they used (or use) for how far the rails would be from an embankment or cut they had made.
My layout will only have a small hill on the outside of a turn to really worry about. But when I started looking at the hill, the question of how close to get to the rails popped into my mind. I figured I could convert from feet to HO scale. So, the real world measurement was what I was really asking about.
Thanks for the input. I’ll be sure to clear my longest/tallest car and loco.
Actually, yes. There are engineering guidelines for the maximum slope depending on the type of material, and then there are railroad clearnace diagrams - Plate A, Plate B, etc. This sort of thing could often cause headaches for dispatcher tying to route trains, if they contained a car that was over height or over width and one route had tighter clearances than others. I forget offhand which plate was the ‘standard’ - where the railroad was expected to have at least that much clearance on the main lines so as to facilitate proper interchange. Tighter clearances might be found in industrial situations, larger ones out on the main if it was feasible to do so when building the railroad. In more modern times this has resulted in places where double tracks liek in a tunner are reduced to a single track in the middle - where there is greater clearance, for modern cars liek tri-level auto racks and double-stack containers.
–Randy
Randy,
Great, that seems like what I’m looking for. Do these clearance diagrams – Plate A, Plate B, etc. – exist on the Internet anywhere?
While the plate dimensions are critical, railroad companies also have diagrams (called, “Common Standards,” or something similar) for acceptable cross-sections of right-of-way. Usually, the dimensions are far larger than the size that even the largest plate would require. I don’t know if NS has theirs on-line. Some time ago I found the BNSF standard cross-section specifications for new industrial track - far wider and more specific than anything model railroaders would use for a high speed mainline(!)
You might send an inquiry to the SOU historical society (I’m sure there is one.) They may have exactly what you’re looking for.
Chuck (Modeling Central Japan in September, 1964)
Also keep in mind that RR’s would expand and increase these as time went by, so they would have the ability to handle oversized loads. I believe SOU sent engineering crews to physically measure and document each and every clearance along their main lines - every grade crossing gate, every sign and milepost, every bridge, every overpass … that way they knew they could handle a load XX feet wide and XX feet high from (point A) to (point B). If a shipper called in and said “I have a load XX feet high that needs to go from (point C) to (point D)”, the people taking the call could check the guide and quickly know if they could handle the move or not.
Brad
Hi again,
As a side note:
It was mentioned in this string that the narrow gauge RRs often were strapped for money and had “less generous” clearances. If you ever take the Durango & Silverton scenic RR trip (Durango to Silverton) there are places where one could easily put their hand outside the window and touch the rock face cut into the side of the mountain/hills.
Chuck, Brad, et al.,
Thanks again for input. Yep, I’ve bumped into a Southern Railway historical website. I’ll check that out for a contact – good idea. I guess I was thinking that any significant rail line would know what could be handled on their tracks, either with minimum clearances or with physical measurements. Also, since it seems rail lines “share” freight, I figured there would be an “industry standard”; maybe not. . . .
How long is from here to there?
It surely depends on the era, the railroad, its function and a host of other issues.
A narrow gauge logging or mining railroad would have closer clearances that the Eire-Lackawana. (The Erie had the greatest clearances at the time.
It all depends on what plates are allowed. The plate is the dimensions allowed to certain classes of cars and equipment. The most common plate (I think) is “C”. Thus you would have to run class “D” cars by a different route.
In cities buildings and retaining walls can come within inches of moving trains. Some commuter railroads have gantlet tracks that allow the mainline adequate clearance for the widest and fastest loadings, yet can switch the commuter train closer to the platform to make its stops without having unreasonable gaps through which the geese (passengers) can fall.
On NYCT the IRT is limited to 9’ wide x 50’ long cars. The IND and BMT run 10’ wide cars which might be 60’, 67’ or 75’ long… but some routes cannot accommodate the 75’ cars without collision with trains on adjoining tracks on curves.
There are specifications, an “envelope” that cars must fit inside of. There are other specifications on where wayside structures may be in relationship to the closest rail. There are places along the wayside that are reserved to certain trades for their purposes such as signals, power, etc.
The ONLY encroachment of the wayside into the “no-man’s zone” permitted is the platform edge, and that this edge must be made of “Sacrificial Material”.
Ergo: It is up to the railroad to specify these things, and so there is no hard and fast standard.
ROAR
Does this answer your question.
BTW: It was shot from the rear of an AMTK train running on BNSF by a friend on another forum.
Lion,
Well, that answer isn’t quite in feet and inches, but it certainly gives an explicit qualitative answer – CLOSE!! I first thought all those wires were telephones lines!?!
However, I DID get a response from a Southern Railway “expert” – as recommended in an earlier reply – who sent a link to the railway’s roadbed section plan. Looks like it’s about 12 feet from center of rails to cut. . . .
http://www.southernmodeler.info/Hundman/SOU_Standard_Plans_-_Roadbed_Section
s_-_MM_199308.pdf
Slide detector fence.
Yep, after I got over how “tight” the sides of the clifts were, it occurred to me that rock slides would wreack havoc and the fence would be more important than phone lines! Pretty impressive photo whether phones or slides were in mind with the wires. . . .
As far away as it can possibly get, especially if the railroad is bankrupt! [D)]