QUOTE: Originally posted by EFCO And under the proper conditions a brake shoe can heat up enough, and thereby transfer enough heat to the wheel, for the wheel to come off the axle! Big problems then. Luckily it doesn't happen often.
Never too old to have a happy childhood!
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QUOTE: Originally posted by Hugh Jampton QUOTE: Originally posted by zardoz QUOTE: Originally posted by uzurpator QUOTE: Originally posted by zardoz The further a brake shoe is from the wheel the less effective is the braking effort. On the Metra suburban equipment the brake shoes are set to be only about 1/4 inch or less from the wheels. So as the shoes on the ore trains are worn, the braking effort is reduced (not a desireable condition). Huh? They are pressure activated - the efficency is based on said pressure, not "how far from the tread" the brake shoe is... As the brake cylinder travels further out (as is the case if it has to travel further to meet the resistance of the wheel), the cubic inch area that the aux resevoir has to fill increases; and as volume increases, pressure decreases, thus a reduction in braking effort. Technically yes,, but as the volume of the aux reservoir is a lot greater than the volume of the brake cylinder the effect is negligable.. BTW: Does anybody else get a security alert pop-up thingy whan they open this thread?? Something about a certificate whatnot..
QUOTE: Originally posted by zardoz QUOTE: Originally posted by uzurpator QUOTE: Originally posted by zardoz The further a brake shoe is from the wheel the less effective is the braking effort. On the Metra suburban equipment the brake shoes are set to be only about 1/4 inch or less from the wheels. So as the shoes on the ore trains are worn, the braking effort is reduced (not a desireable condition). Huh? They are pressure activated - the efficency is based on said pressure, not "how far from the tread" the brake shoe is... As the brake cylinder travels further out (as is the case if it has to travel further to meet the resistance of the wheel), the cubic inch area that the aux resevoir has to fill increases; and as volume increases, pressure decreases, thus a reduction in braking effort.
QUOTE: Originally posted by uzurpator QUOTE: Originally posted by zardoz The further a brake shoe is from the wheel the less effective is the braking effort. On the Metra suburban equipment the brake shoes are set to be only about 1/4 inch or less from the wheels. So as the shoes on the ore trains are worn, the braking effort is reduced (not a desireable condition). Huh? They are pressure activated - the efficency is based on said pressure, not "how far from the tread" the brake shoe is...
QUOTE: Originally posted by zardoz The further a brake shoe is from the wheel the less effective is the braking effort. On the Metra suburban equipment the brake shoes are set to be only about 1/4 inch or less from the wheels. So as the shoes on the ore trains are worn, the braking effort is reduced (not a desireable condition).
QUOTE: Originally posted by virlon >>That is what happened to that train that ranaway years ago in California and derailed on a curve, crashing into some houses. I had read that even 24 hours after the wreck, some of the train wheels were still too hot to touch.<< The main reason for the runaway on SP on the Cajon Pass in 1989 that you speak of was mainly due to insufficient Dynamics. Also, the weight of the train was not correct on the crews paper work. The Engr and Condr both talked about the speed they were making up the grade out of Palmdale and thought something was not quite right. They asked for and received a helper, which DID not inform the head end that they only had one of two units working in dynamics.That was the reason for the runaway. Virlon saveyour ticket..... the P.E. will rise again.
Mechanical Department "No no that's fine shove that 20 pound set all around the yard... those shoes aren't hell and a half to change..."
The Missabe Road: Safety First
QUOTE: Originally posted by edblysard Believe it or not, the shoes on cars are held on with only a simple long pin...it clips through the brake head and a few slots in the steal back of the shoe. A good carman can change out a set on one side of a truck in under a minute. Sometimes, the pin fails, and a shoe gets thrown off. No big deal, every car is inspected when it gets yarded, so the missing shoes get replaced quite quickly. Ed QUOTE: Originally posted by NellsChoo What I don't get is why you sometimes see brake shoes along the rails! Is it possible for them to just plain fall off? Do they ever replace them out on the road??
QUOTE: Originally posted by NellsChoo What I don't get is why you sometimes see brake shoes along the rails! Is it possible for them to just plain fall off? Do they ever replace them out on the road??
QUOTE: Originally posted by coborn35 I live near the CN's former DMIR Proctor Hill that leads to the Duluth Docks and when trains come down, man, there is basically a blue colud with a train in it. Wouldnt this burn the shoes off the ore cars?
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