The internet is such a wealth of information that one can develop the misleading impression that all information is available online. Not but sometimes you turn up something useful. CN Engineering Specifications for Industrial Tracks is one thing I found recently while attempting to answer questions about various track details for Comstock Road. While this is the current CN document intended for modern customers, it does give me help in making more plausible guesses where required.
Some of the information is not of direct interest to modelers since model railway engineering and permitting processes are somewhat less formalized but some of it is bang on. For instance, I gleaned the following useful numbers from this document:
- Minimum ballast shoulder for jointed rail is 6″ beyond the tie ends. 12″ for welded rail. Hmmm.
- Additional sub-ballast width is required on the diverging side of turnouts to provide a working area for the rail crew to stand.
- A spur of over half a mile requires a runaround. Long backing move without a caboose are neither fun nor safe for the guy riding the last car.
- 25′ between main and industrial track unless space is unavailable, 14′ minimum between adjacent industrial tracks.
- 20″ spacing on leads, 22″ on body tracks.
And some we are just going to pretend either didn’t apply in the 1970’s or just isn’t doable in the space I have:
- Minimum rail weight of 115lbs. Depending on sources and rail profile that is either code 125 or code 138. I have Right O’ Way code 100 steel. That is plausible for a circa 1900 era leftover but not especially likely for 1940/50’s new construction. I am claiming reuse as a wartime expedient.
- A minimum radius of 9° of curvature. Which is something like 160″ in 1:48 O scale. The entirety of Comstock Road is 144″ long… We are just going to prohibit autoracks and proceed.
There is also a bunch of details regarding clearances and grades that I will have to look at more closely although model standards will likely suffice. The real GECO spur crosses the actual Comstock Road and ascends to the last customer on what looks like a fierce grade of 5% or more so I doubt I will come up with anything implausible. (My intent is for the back industry siding to be up a grade to give a bit of topological interest.)