Nostalgia & History > SP commute power on Donner

Three of SP's commute fleet head up a westbound at Alta California. 3199-3200-3205 will be hauling passengers tomorrow morning. The slide mount is marked February 1984.

---

Great Pic as always.........Do you have any of H24-66 pulling between SF and Reno?

espee99 Wrote:
-------------------------------------------------------
> Great Pic as always.........Do you have any of
> H24-66 pulling between SF and Reno?


SP may have used the H-24-66s on weekend traffic between San Francisco and Roseville, but I doubt they ever went to Reno. If so, and if there is a photograph, it would be rare indeed. - Tony J.

There was one evening when a bunch from the Walnut Creek Model RR Club went down to the old East Bay Club in Emeryville one Friday night in the mid 70's.

The real highlight of the night wasn't inside. It was outside when the Light Power East roared by, headed for Roseville like the proverbial bat.

The earth shook and the noise was something to behold.


Wish I had a recording of that...

There's one electrician that retired from the UP at West Oakland a few years ago, and he used to work out at Bayshore in his younger years prior to it's closing. He always would complain about the commute power getting torn up when it went out on those weekend ventures to haul freight, because he says the traction motors were geared differently than those of freight units and it would put added wear onto the units.

Anyone care to offer any truth to the claims by this electrician?

Did they put in a switch that was for freight/ passenger on the console after the SDP's took over the fleet?

The Commute power weekend schedule was amazing, many times I would see them on Donner Pass on Sunday and then see them flying past in the Monday morning Commute. All sorts of Elmer stories checking the fuel tanks on Friday night as they waited for orders at Santa Clara. You could hear them on the radio all weekend and then seemingly at the last minute they all were collected up and sent to San Jose. Something about a 10 unit light move really caught your attention, not to mention the Gyra-lights, the occasional red gyra light was always interesting.

Standard EMD gear ratio for freight back in the SD40-45 era was 62:15 (62 teeth on the axle bull gear, 15 teeth on the traction motor armature shaft pinion gear), which permitted a maximum speed of 70 MPH without overspeeding the armature (and risking the armature copper windings coming apart, called "birdnesting"). Alternative gearing included 60:17 and 59:18 which I believe permitted maximum speeds of about 80 and 90 MPH respectively.

The problem with a "passenger" gear ratio in freight service is that the minimum continuous speed (MCS) also increased. Whereas an SD45 with 62:5 gearing could operate up to 70 MPH maximum, its minimum continuous speed (full throttle) without burning up the motors was about 9 MPH.

The same unit with 60:17 ratio would have a minimum continuous speed of about 15 MPH.

As long as higher-geared passenger (or commute) units were operated together as a consist, you would hope that the engineer would abide by the traction motor rating rate on the control stand and keep train speed above the MCS. The real problem was if a higher-geared passenger unit was MU'd in a consist with lower-geared freight units, and the engineer operated the consist at the MCS for the freight units, which would potentially put the higher-geared passenger unit in an electrical and thermal overload situation by running it at full throttle below the MCS for more than the short-term ratings would allow.

Up to the mid-1970s (when Metra acquired the F40PHs), CNW used to use many of its commuter-fleet F7A units in freight service between Proviso Yard and Milwaukee or Janesville. The commuter sets would depart Proviso early Saturday and be back home by Sunday night, ready for the Monday morning commute into Chicago from West Chicago.

Yes, up to Roseville on early Saturday morning on the WJRVP ( perishables), starting about 1974, when the SDPs took over the fleet. They would work to Sparks and turn back to Roseville. About 1976, they went to Roseville on Friday night light. July, 1978 to spring 1979, they roamed the west freely as Amtrak GE's took over the fleet. 1981-83, they went light to Oakland and ran to Sparks on the OAOGF (later CPEFF) and OACHT. Then they would work back to Roseville in helper service on Saturday and home to Oakland/ San Jose on the RVSF/WJY, autoparts, UPSFF, UPSFT trains. If a bunch went to the City on Sunday night, Train 108 had them all in its consist to San Jose at 12:35a Monday morning. Six units and two galleries....

WAF Wrote:
-------------------------------------------------------
> Yes, up to Roseville ....


Good info, still working on that timeline.

WAF Wrote:
-------------------------------------------------------
> Yes, up to Roseville on early Saturday morning on
> the WJRVP ( perishables), starting about 1974,
> when the SDPs took over the fleet. They would work
> to Sparks and turn back to Roseville. About 1976,
> they went to Roseville on Friday night light.
> July, 1978 to spring 1979, they roamed the west
> freely as Amtrak GE's took over the fleet.
> 1981-83, they went light to Oakland and ran to
> Sparks on the OAOGF (later CPEFF) and OACHT. Then
> they would work back to Roseville in helper
> service on Saturday and home to Oakland/ San Jose
> on the RVSF/WJY, autoparts, UPSFF, UPSFT trains.
> If a bunch went to the City on Sunday night, Train
> 108 had them all in its consist to San Jose at
> 12:35a Monday morning. Six units and two
> galleries....

Excellent Summary! I recall going down to West Oakland on many a Friday night, and seeing practically the entire commute fleet humming away clogging "shopside" at the Diesel Shop.

Cheers,
Harry