|
|
| Re: Of brake stands and "dramatic braking" (467839) | |||
 |
|||
| Home > SubChat | |||
|
[ Read Responses | Post a New Response | Return to the Index ] |
|
||
|
Re: Of brake stands and "dramatic braking" |
|
|
Posted by SelkirkTMO on Sun Jul 29 06:15:38 2007, in response to Re: Of brake stands and piping, posted by Hoghead on Sun Jul 29 04:14:20 2007. Heh. LOVE the comment ... I've often told of why I was always willing to take out the AMUE stuff instead of SMEE for that very reason. The old AMUE stuff dates back to the early 1930's and had no dynamics at all. Electric assist propagated what the ME-23 stand ordered up which made application quite nice and reliable as long as the 32 volt voltage drop through all those electric portions, relays and magnet valves eventually caught up to you.The R-10's were the first SMEE's in the system (self-lapping with dynamics - well sorta. heh) and they were HORRIBLE as far as the dynamics went, and while you could cut them out, you REALLY didn't want to. The amperage control was pyth-poor so when you took a good service app ("keep them moving, stop them fast") the wheels would just lock up and slide. The infamous "8-edged wheels" of artens were caused by this behavior. And when they faded, each car seemed to fade at its own rate causing individual cars to go over to air, but never all of them at the same time. I've referred to this (as have others) as the "rubber band effect" when dynamics die and the magnet valves finally apply some air. "Bucking Broncos" is about the best I can describe it. Anyone who ever rode them knows what slowing down and stopping were like in those. Meanwhile, the old arnines (AMUE) could stop like a CADILLAC if you knew how to work them and didn't brickwall by knowing WHEN to release and how much to hold with the electric brakes after you did. The R-32's were MUCH better than the artens although as originally delivered (like the 11's through 30's) they were a pain in the rump too though the severity of wheel lockup wasn't anywhere near like R-10's. The dynamics were just WEAK compared to the artens, and seemingly faded faster. I never liked dynamics. First time I encountered dynamics that were NICE was on the R-143's ... VERY smooth handoff from drag to air. But on all of our car classes, when you ran in snow and ice, you always knew to bite a couple of pounds and not release it all just to keep the shoes setup on the wheels. My understanding is that on most of the current fleet, there's actually now a "snow brake" position which we didn't have years ago. Looks like that old trick worked out after all. :) Just wanted to say THANKS for the convo ... to me, this is a WHOLE lot more interesting than the usual stuff! |
|
|
|