On the first video, where he is pushing just a few feet, when the rotary finally gets ahold of some snow and throws it, is that the B unit finally getting some load from the blades that makes the noise and smoke temporarily? Birken
Great videos, but now I'm really confused. I've never had an explanation of a rotary's operation other than spinning blades slinging snow, so I hope you guys can help me out. How is the spinning rotary blade powered, steam, electric, diesel? My guess is steam because I see vapor coming out in various places, also its whistle sounds like steam. But here's my confusion...what is the purpose of the B-Unit? My knowledge of B-Units is that they use a diesel prime mover to generate electricity, which then is used for whatever. Obviously the electricity is not for track power because the three locos in the YouTube video are providing that. I doubt if it's being fed to the rotary because it appears to be steam powered. Of course it could used for a cab heater to keep the rotary operator warm...nah. :tb-wacky: Anybody? :tb-nerd:
It is my understanding that rotaries were first all steam powered. The old ones on the Cubres & Toltec still are. I know many of the standard gauge railroads converted their steam powered ones to electric by using a traction motors to turn the blades. The booster unit was added to generate power to turn the blades much like slugs are powered. Many of the booster units also have flash steam generators left over from providing steam for passenger cars. I think I can see the steam generator vents on the roofs of the B units in the videos. What they still use the steam for, I don't know. Perhaps there are certain functions on the plow that still require steam and are not easily converted to electric?
The rotaries have all been converted to electric power although they were originally Steam powered. The b unit provides the power for the rotary. The B unit's steam generator also provides steam which is used to keep the blades warm so the snow doesn't stick to the blades. It also obviously drives the whistle.
OK, that explains the volume of vapor coming out and around the rotary blades, which caused my original confusion. Also it makes sense that rotary power would be electric being more efficient and controllable, and less maintenance than steam. :tb-nerd: Thanks YoHo.....:thumbs_up:
The F unit B unit is strictly for generating electricity. They have no traction motors, or dynamic brakes now. They are pushed by what ever the railroad has handy. SP used SD45T-2's, some times up to four in between a pair of rotaries.
Rotary B units The SP rotary B units are F7 or F9 passenger power with the traction motors and cab removed. This leaves a diesel-electric power unit with steam for passenger service. Those capabilities are diverted to turning the traction motor (conversion from steam about 1957) driven blades, and the steam de-ices the windows, blades and wings. I can't remember if radiator space heating occurred...
My wife works at the 24 Fitness in Citrus Heights. Apparently the wife of a Retired UP/SP engineer said that her husband was called up, first time in 13 years to help with plow service since no one on staff had actually used them in real snow removal.
I noticed yesterday that one of the Jordan Spreaders (couldn't see number) along with a bunch of flangers and Snowfighting GP38-2s are in Roseville. I assume for repairs.
