Dr Zarkoff Wrote:
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> Dynamic brake effort is a function of the traction
> motor characteristics and engine weight (on
> drivers). The 1127 is approximately the weight of
> a GP7/GP9, and the traction motors are the same
> (traction motor cooling air ducting is different).
> In dynamic, all you can do is regulate the current
> generated, not the voltage, and the max current
> for dynamics is around 750. So the retarding
> capabilities are approximately the same. I've run
> the 1127 on the SP several times. The first time,
> the dynamics hadn't been turned off, and it's a
> little disconcerting to have that fan turning so
> fast right in front of the windshield. The next
> few times I ran it, the dynamics had been turned
> off (most of these cow units had already had this
> done). Where the 1127 is "smaller" is in pulling
> power and speed because the diesel engine has
> fewer cylinders.

Oakland starting disabling the dynamics on the units that landed there in the mid-Seventies because of GRA issues.

The 1127 (and 1228) weighed 229,340 pounds when built, making those two heavier than the other Pacific Lines SW8's/TR6A's, which all weighed between 207,000 and 212,000 pounds. The relatively light weight tended to make them slippery. On the other hand, the four T&NO SW8's weight 233,000 pounds. For comparison, SP's freight GP9's weighed in the 249,000 to 256,000 pound range.