SRB Speed Restrictions Late 40's / early 50's

Is there still an SRB Operating Officer reading these posts that can recall why PRR M-1a locomotives in thru pool service between Southport & DeWitt had a 10MPH speed restriction on #4 track at the Seneca River Bridge? M-1's were further restricted on the entire Syracuse Division not to exceed 30MPH. What made this class of locomotive unique to these restrictions. It's my understanding some number of PRR M-1's were equipped with ATS @ Altoona for Southport assignments.

Wow... learn me something... why were PRR engines heading to DeWitt?

-otto-

Otto -

The NYC and PRR interchanged at Himrods Jct on the Fall Brook. Sometime during the steam age, the roads made an interline agreement, where NYC and PRR crews and power would run between Southport Yard in Elmira and Dewitt. It made for a more efficient interchange operation, because neither railroad had to wait for the other at Himrods. That continued up to Penn Central, and even then the crew districts had the interline agreement until the rosters were combined. NYC and PRR crews, IIRC, equalized mileage on a monthly basis.

I remember seeing the Southporter at Corning and Lyons in 1965, with PRR power and caboose (oops, "cabin car").

I suspect that the reason for the speed restriction on Track 4 on Bridge 636 at Seneca River was because of close clearance. The bridge was built in 1924, so the NYC standard design load would have certainly accommodated an M-1a with no speed restriction. A railroad wants at least six inches clearance to run trains at normal speed, but can go down to two inches or less at 10 mph, account rocking and rolling at higher speeds. Some steam locomotives "waddled" at certain speeds, and the M-1a could well have displayed that behavior. That probably also accounted for the overall division 30 mph speed restriction, because the NYC had closer track center spacing than most other eastern railroads.

Thanks for the logical reply...makes sense although I must confess never knew we had closer track centers than was standard.

As far as I'm aware, the M1's weren't allowed north of Southport because of bridge weight restrictions north of HO Tower in Horseheads. From what I understand, only L!, I1 (short tender only) and H-class freight power (or E- and K-class passenger engines) could operate over the northern part of the Elmira Branch because bigger engines such as M1's or I1's with coast-to-coast tenders weighed too much for the bridges on that part of the PRR's line.

I will have to dig out some old timetable to see what I can find but in the
meantime I think it might be because the PRR engines were not equipped
with ATS equipment, I suspect although I do not know this for sure
Noel Weaver

Noel -

PRR equipped some of their power with NYC Intermittent Inductive Train Stop equipment to operate between Lyons and Dewitt, and between Girard Jct and Erie, PA. The ICC (later the FRA) did not allow exceptions for foreign power except in individual cases that required waivers, or when the equipment failed en route.

I don't have a PRR roster that would show the locomotives that were equipped.

Gordon

Hi, Guys:

Don't forget about the PRR rights between Sandusky and Ashtabula for empty hopper train movements.

ChiefTroll wrote:Noel -

PRR equipped some of their power with NYC Intermittent Inductive Train Stop equipment to operate between Lyons and Dewitt, and between Girard Jct and Erie, PA. The ICC (later the FRA) did not allow exceptions for foreign power except in individual cases that required waivers, or when the equipment failed en route.

I don't have a PRR roster that would show the locomotives that were equipped.

Gordon

Interesting, I did not know that. I will try to check some old timetables
for any possible light that can be shed on this one.
Noel Weaver