Operations and Dispatching, Seligman Sub

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Operations and Dispatching, Seligman Sub

Post by softwerkslex » Wed Feb 21, 2007 3:11 pm


I am researching the Seligman sub and studying scheduling as part of my PhD in operations (business, math). I have the cooperation of BNSF management, but they are busy and maybe some questions can be answered quickly here without troubling them. I have the official track diagrams from BNSF and articles from recent issues of Trains that cover operations on this line. I also have "TPM" runs, which are computer simulated timings of typical train trips over the line.

Here are some current questions I would like to answer:

1) What guidelines should I use to set the minimum headway for train operations? I am thinking of the minimum headway at speed. Will it be different between different classes of train, e.g. longer headway between Amtrak and preceding freight?

I have a 2003 Trains magazine article that covers the old Santa Fe 251 territory, Winslow to Gallup, and it shows that under 251 rules trains maintained a 3 block separation (red block, yellow block, flashing yellow block, green). If these signals are approximately 2 miles apart, then I would give each train an 8 mile route headway (current block plus three empty trailing blocks). At 60 mph this would be an 8 minute headway, and I might round this up to a 10 minute headway for simplicity and to provide a time buffer. Is this a reasonable analysis? Has the conversion to CTC changed the headways and operating patterns?

2) There are some odd milepost entries at the Barstow end of the TPM simulations. Some mileposts are out of sequence. Are these due to certain yard tracks belonging to UP, or the Cajon or Mojave districts? I think I will limit myself to mp 10 to 745 inclusive, and avoid debugging these yard tracks.

3) The TPM data shows that line speed is uniform over the route Belen to Barstow, with just a little random variation. Is this an accurate picture? Is any particular segment a bottleneck for this route?

Just in case anyone asks: I can not share these original source documents with anyone, as obviously they are confidential. Any insight from operating employees or from regular train chasers would be appreciated.


UPRR engineer

Post by UPRR engineer » Thu Feb 22, 2007 11:46 am

Just in case anyone asks: I can not share these original source documents with anyone, as obviously they are confidential.
Start scanning there Steven. You want something, well we want something also.


[seligman sub] Documents

Post by softwerkslex » Thu Feb 22, 2007 12:12 pm

Obviously, documents supplied to me by BNSF are confidential for many reasons, not the least of which are homeland security fears. If anyone has specific interests, I would be willing to make inquiries.

UPRR engineer

Post by UPRR engineer » Thu Feb 22, 2007 12:37 pm

Check you Private Message dude.

Whats your hang up? Cant make sence of the timetable? All your questions are answered in there.

Theres no rhyme or reason for/to train spacing, or headway as you put it. In the real world your only as fast as the guy ahead of you. Even if you tried to run the same trains, from the same terminal, at the same time everyday, things will end up being different. Theres your paper dude.


Post by freshmeat » Tue Feb 27, 2007 12:58 pm

I'll be a pain in the ass and tell you that I personally don't think this is the proper venue to post such information.


Re: Operations and Dispatching, Seligman Sub

Post by IC&E6565 » Wed Aug 06, 2008 2:01 pm

All I know is that "DS-10" Controls from Winslow to Seligman and "DS-11" controls from Winslow to Topock I think it is, both are in Forth Worth.

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