SIR Tower B |
The only mast signal was located on track 1 approaching the St George terminal and it was only capable of displaying slow speed indications due to the lack of any orbitals.
While the 2004 re-signaling project fortunately kept the CPL signaling, any though that CTC operation with multiple new crossover interlockings would bring about orbital equipped double sided CPL masts on both tracks was dashed by the incorporation of a new PRR-style pulse code cab signaling system without intermediate wayside signals. Although the plethora of new interlockings likely increased the total number of CPL signals in service on the SIR, the use of cab signals with ATC allowed the SIR to present a reduced menu of B&O CPL signaling.
Although some high mast and gantry mounted signals were added, orbitals were limited to the 12 and 6 o'clock positions, as cab signals were expected to take up the task of controlling speed approaching the next fixed signal, even in the case where signals were ostensibly back to back.
This limits signal indications to Clear, Approach, Medium Clear, Medium Approach, Slow Clear, Slow Approach, Restricting and Stop. Limited speed indications are not used and I am unsure as to the use of Stop and Proceed as any wayside signal that can display Stop and Proceed can also display Restricting.
One interesting addition to the B&O CPL rule set is a Flashing yellow / with 12 o'clock marker for what I have been informed is "Approach Proceed Cab", which would replace Approach Medium and Approach Slow and thus saving on the need for extra orbital modules. I suspect this indication would only be displayed at back-to-back wayside signal locations and could possibly also serve as an Advance Approach as well, which it might be doing in the above situation where a BL20 MoW diesel was making a relay move. Note that while the CPL dwarfs are authentic GRS equipment, the high CPL equipment is long out of production and the SIR opted to use Safetran PL targets with CL-20 modules as the markers.
That about sums it up. One could simply say that the SIR uses B&O CPLs, minus indications for Approach Medium, Medium Approach Medium, Approach Slow, Medium Approach Slow, but with the addition of Approach Proceed Cab. However, I am happy to report that after some painstaking research I was able to confirm that there exists at least one 10 o'clock orbital in service on the SIR and it is located at the Tottenville Interlocking 6W signal (west end of the track 2 station platform).
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BTW, the above video proved to be a great resource for the SIR's Tottenville terminal operation. Skip ahead to 8:30 to see the Approach Medium and 7:30 for an eastbound train approaching Tottenville under a Medium Approach.
The flashing yellow with upper marker is an "Approach Cab-Signal Proceed." As I understand, it is used when a distant indication is needed for reduced speeds (i.e. it has replaced the functions of Approach Medium and Approach Slow on fixed signals). I believe that 6W at Tottenville is the only signal left with an offset marker and therefore the only one that can show the traditional Approach Medium.
ReplyDeleteDo you have a rulebook? I just have the interlocking diagrams and the signal displayed at Victory appeared to be an Adv Approach to a stop a St George for a BL20 relay move, but Approach Cab Speed proceed would make sense from an operational point of view.
DeleteI've seen a copy of the rulebook issued right after the resignaling project, and that aspect name came from there. I believe that is the best aspect displayed at Victory and it can be followed by another at Slosson and then a Slow Approach into an unoccupied station track. In older days the B&O would have used Approach Medium > Approach Slow > Slow Approach (or maybe Approach Slow > Approach > Restricting if they considered the station tracks non-signaled).
ReplyDeleteThanks for the info, I'll make the change.
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