This seems rather elementary once one thinks about it.
The 1400 number series (and also the 1900's & 1800's) were numbered as such for
dedicated passenger service. They very rarely ran in freight service (I'd
imagine the 89mph gearing didn't help). The other FP7's in the 4000-series, and
FPA/B2's, RS10's, and GP9's were dual-service units with steam generators but
65mph (75 in the MLW's?) gearing to run in freight service, and could be
pressed into passenger service as needed.
Under ideal conditions, your railway would try to run its trains with the units
equipped for passenger service at all times. So, why not equip all the units
dedicated to passenger service with the roof-mounted gyralites and icicle
breakers. No need to equip the B-units if all the A-units have them. And the
1800's were based out east and rarely ran on The Canadian, that could explain
their absence of gyras and icicle breakers.
Dual service units would ideally be used on an as-needed basis in passenger
service, and thus equipping all of them would be an extra cost.
Dan D
--- In cpsig@xxxxxxxxxxxxxxx, "Doug Cummings" <DougCummings@...> wrote:
And I point out again, and must ask again, that if this was indeed the
purpose of the roof gyro light why was it only applied to a handful of
locomotives that were dedicated to passenger service and ran both in the
east and in the west. No one has yet offered an answer to that question. I
know this is what you were told, and I am sure whoever told you was not
trying to mislead you, but if you think about it the explanation is not
logical.
Doug