Looking at the new project layout in MR has brought up a question in my mind. When did concrete ties come into use on western lines such as the UP? Were they around on SP and DR&GW in the late 1980’s before UP took them over or would wooden ties be more correct in such a time frame?
Following experiments that dated to the 1920s, which were unsuccessful, concrete ties reached sufficient maturity in the early 1970s to be used on something other than a strictly experimental basis. CN began its concrete tie program in 1976, UP in 1982, and BN in 1986. UP’s first major installation was at Crestline, Nevada, in 1982. D&RGW never installed a single concrete tie prior to its merger with SP. SP installed none of any significant quantity that I can recall prior to its merger with UP in 1996.
Concrete ties are installed as follows on Class 1 railroads:
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In heavy curve territory to hold gauge and eliminate spike kill in wood ties
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On extremely sharp curves where wood ties have difficulty preventing rail rollover on the inside rail against the forces of long, heavy trains, particularly in terminal areas
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In large-project main track and siding new construction in heavy tonnage territory
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In industrial spur new construction if they are less expensive than treated wood
Concrete ties are often not installed:
- On ballasted deck bridges due to difficulty with ablation
- Through grade crossings
- Through turnouts
- Open deck bridges
Concrete ties cannot generally be successfully installed in-face with wood ties because they are at a different spacing (typically 24" instead of 21"), require a different ballast section, require a different ballast specification (size, hardness, etc.), require different machinery for construction and maintenance, and have a different section modulus. A few railways tried to install them in-face with disastrous results. Other than the sections of wood tie in the discrete locations listed above, concrete ties are installed out-of-face (i.e., continously, not spot or intermixed). In locations where new tracks are being constructed it is very common to continue to use wood on the existing track and concrete on the new track. Repla
Thank you, your information clears up a lot of questions for me. I’m basically trying to nail down a time frame when SP, D&RGW, UP and even locos in the failed SPSF merger could be seen roaming the rails so the presence or lack of presence of concrete ties could be important.
I think even after UP acquired the D&RGW/SP and the SF became part of the BNSF that locos could be seen in their original paint so I have quite a span of time I could possibly use.
Thanks,
MT