Although rare now, you can have a current of traffic without signals. Although also rare, you can have two main tracks without CTC or signals.
In days gone by, some railroads, off hand and specifically I’m thinking of those that used the US Uniform Code, had no double track distinction in the rules. If there were two main tracks, no matter how operated, it was listed as Two Main Tracks. The definition was “Two Main tracks, the use of which is subject to the rules.” The timetable would list the method of operation, i.e. current of traffic, signal indication, etc.
While some what more uniform now, it seems on the railroad we all speak the same language, but we have different dialects within that language.
Jeff
ps. Even working railroaders will casually use double track or the double main, no matter the method of operation.
I would expect that UP has a much different understanding about the intended operation of their property than you do. I also expect that understanding is based on many more facts than any one on the outside is privy to.
During my career I worked on four different division of the B&O. Each division reflected the personality of the Division Superintendent and were different railroads separated by a common rule book.
When I went back to Dispatching in 1990 on CSX I ended up working on six different divisions. While there were differences in how the Division Managers handled the operations of their divisions, from the Dispatching standpoint the Dispatch Center and its management and the implementation of CADS forced a high level of uniformity of operations on all areas of the company. When CSX decentralized Dispatching in 2008 with each division’s dispatchers moving to locations at the division HQ - each division started doing some things differently than other divisions. Dispatching was re-Centralized starting in 2017. Having retired in 2016, I can’t comment on what has been taking place since I pulled the pin.
It may be good to look at what JohnQuilter was saying about those four miles. Any slow going tends to bunch trains together. Once the slow going is passed, trains tend to get farther apart. By two-tracking that slow going section, the bottleneck area is passed with ease, especially if the trains involved are fleeted.
Looking at the area on Google Earth, the line has several sharp curves and track close to the bottom of river bluffs. I think I see the location where track was replaced after the oil-train accident – concrete ties? There is also a section running on fill which is not wide enough for double track with suitable center-to-center distance.
It would be interesting to see what is in the current court docket, even if we aren’t privy to UP’s reasons for prioritizing this particular region. I don’t see an objective high-cost problem as at Abo Canyon.
Here’s a nice collection of UP photos taken near Mosier, OR, including a few of the oil train derailment and fire. It appears that the west end control point still features some classic searchlight signals. flickr Mosier, Oregon photos
I did a little math on the amount of time trains would need to get between the end of double track west of The Dalles and the next long passing siding west of Hood River, OR. My rough calculations came up with 29-37 minutes, assuming average train speeds of 35-45 mph due to all of the curves. That’s pretty painful from a train dispatching standpoint on a line with a sizeable amount of traffic.
I suspect that another motivation for UP to extend the Mosier passing siding to a 4-mile length is the ability to stash 12-15,000 foot long eastbound trains away without clogging up the double track and terminal at The Dalles.
I agree that it’s a long distance between the double track and the next large siding, compared to the rest of the subdivision. Mosier siding is 6380 ft, one of the shortest. Most are in the 9900/10000 ft range, with a few larger. I could see them lengthening Mosier, but it would only be adding maybe two miles to it. Unless they want to scrap the current one and build from scratch nearby.
From what I read once, I don’t know that The Dalles is much of a terminal anymore. I believe crews have been running through for years.
I know nothing about the UP territory in this discussion.
With that being said, a particular single track territory I worked had multiple trains having a cumulative 23 hours scheduled for working at a location that was intermediate to control points that had a ‘track speed’ running time of 40 minutes between the locations without stopping.