I was just longing at a A-B unit when it occurred to me that a modernday slug is nothing more than the child of the old B-units. Again having no cab.
Not exactly but close. A B unit is a cabless A unit. A B unit has its own prime mover and generator to make power for its traction motors under control from the A unit. A slug doesn’t have a prime mover or generator (or alternator). It uses excess power from the master unit to power its traction motors. So while it is a support unit the way a B unit is to increase power and tractive effort the way it gets that power is different.
Thanks for the lesson, I see I jumped the gun a bit and made an asumption.
Just to add to your confusion, there are slugs that have cabs, too. CSX is well-known for its road slugs rebuilt from GP30/35/40’s numbered in the 2200/2300 series. KCS had a handful of road slugs rebuilt from F7A’s that kept their cabs. BNSF has some hump slugs rebuilt from SD9’s that look like SW1500’s with a very long hood and C-C trucks.
A BN/BNSF slug: http://www.trainpix.com/BN/EMDRBLD/TEBUC6/6289.HTM
A CSX slug: http://trainweb.org/csxphotos/photos/RDMT/2204CSX-yn3.jpg
And then there were the Milw slugs that they ran out of Tacoma. They were ABA F-7 sets but the B units had the engine/generator sets removed and each truck on the B drew elect power from the adjacent A.
Good Morning.
One of the more exotic items out there was the GP9B. PRR had them, and I think UP did as well.
work safe
GP9B’s definitely qualify as exotics. Only PRR/PC/CR (40) and UP (125) had factory-built GP9B’s. ATSF also had 5 GP7B’s. Factory-built hood unit boosters of any type were rather uncommon, including AS616B, GP30B, SD24B, DD35B, GP60B, C855B, and B30-7AB.
However… The GP9b is another anomolie. The PRR GP9b version had a full set of controls but was minus the cab. Come again! Yep, it had a full set of controls and the engineer when needed would stick his head out the porthole to run the engine (Usually around an engine terminal). i sure wouldn;t want to go on the road that way! I suppose the commnets that management got after that experience convinced them saving teh cost of a cab just wasn’t worth it. Up didn;t learn until they had GP30b units.
Some F B units also had controls and a hostler’s window so they could be moved short distances by themselves.
Rick
There are also more modern proper B units
from http://www.rrpicturearchives.net/
There are also other B units that still have the cab, either left as-is or with the windows welded over
Tim
If I am not mistaken (which someone will be sure to let me know) most of those late model B units were made from wrecks where the cab was destroyed.
“ndbprr” suggested that: “. . . most of those late model B units were made from wrecks where the cab was destroyed.”
That’s true in many cases, however, the Santa Fe bought 23 GP60B cabless boosters in 1991. They were painted silver and red to go with the road’s “Super Fleet” GP60M wide-nose cab units.
So long,
Andy
The CPR also had slugs. These were built from a variety of locomotives. The list includes:
ex SOO SW1200 (3)
SW8 (3)
SW900 (4)
F7B (2)
SW9 (1)
SW1200RS (4)
GP9u (1)
All of these units (minus the F7B’s) retained their cabs and bodywork. The exhaust stack and the front grill on the switcher units were removed.