Yonge Subway Headway Study 1988 (Part 3)

This section presents considerations for the vehicle fleet and yards required to house these cars.  An important consideration for any decrease in headway is that the number of trains in service goes up.  This generates added capital and operating costs for an expenditure that addresses only peak period demand.

A proper comparison of lines would look at what happens if the fleet is expanded (regardless of the technology) elsewhere so that new off-peak service is available in a corridor that does not now have rapid transit.

As we will see later, the additional vehicles are a substantial portion of the total project cost for peak headway improvements on an existing line.

One point worth noting here is that the spare ratio included in the calculations is only 12% compared to the more generous 16% used today. This affects capital costs for vehicles and carhouse/yard space.

Chapter 3 Vehicle Considerations begins by talking about a proposal for wider doorways. This eventually showed up in the design of the “T1” car.

Also proposed is the acquisition of a 7th, 50-foot long car that would add capacity to existing and future trains. In the context of 1988, this was proposed as a third car added between a married pair. For the new “Toronto Rocket” unit train sets, it would be a short, seventh car in the consist. Seven car trains would completely fill station platforms requiring precise braking. This would be provided by Automatic Train Control.

The longer trains would also have some effects on terminal operations (longer trains take more time to clear crossovers). The study mentions that there would also be signal effects, but only in a non-ATC environment where existing signal circuits may not be able to handle 500-foot long trains. Similarly, complications with yard operations mentioned in the study do not apply to the new TR trains that will be single units regardless of their length.

At this point, the TTC has not publicly addressed the option of adding a seventh car as a way to increase line capacity.

One other small consideration related to the fleet is the impact on the traction power supply. More trains, especially operated at “high rate” with faster acceleration, draw more peak power and this triggers the need for power distribution changes.

Appendix III Vehicle Requirements lists the calculations of fleet size in detail for various scenarios. I have included it here so that all vehicle-related discussions are linked from one post.