Do the air brakes release the hand set brakes, or does the hand brakes over ride the air?
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rrman posted:Do the air brakes release the hand set brakes, or does the hand brakes over ride the air?
Hand brakes are manually set, and thus must be manually released, on each and every piece of rolling stock. Thus, the air brakes do NOT "release the hand brakes".
Hot Water posted:rrman posted:Do the air brakes release the hand set brakes, or does the hand brakes over ride the air?
Hand brakes are manually set, and thus must be manually released, on each and every piece of rolling stock. Thus, the air brakes do NOT "release the hand brakes".
Thanks HW, that's what I assumed and it made sense, but I have been wrong (surprised) before.
No.
and now days you have to tie the handbrakes, then release the air brakes to ensure that the handbrakes work
However . . . there have been manually-activated power hand brakes on locomotives for several years. The crew member applying the hand brake pushes a button, the electric motor winds the brake chain to a predetermined tension, and stops. The reverse process releases the hand brake. Small lights indicate whether the hand brake is applied or released.
This feature is optional, but has been widely embraced, as it eliminates one source of employee injury. A crew member seemingly in great condition sometimes pulls a muscle when applying hand brakes. We try to educate them to stop when the tension on the brake wheel or ratchet handle indicates that the brake is snug. Some want to apply a Charles Atlas handbrake which is not only risky for them, but also for the employee who may have to overexert to release that brake. The Charles Atlas method does not apply any more securement than does a snug hand brake, in spite of the widely-held misconception that the opposite is true.
Safe securement of cars or engines left standing is very important for the safety of everyone.
Number 90 posted:However . . . there have been manually-activated power hand brakes on locomotives for several years. The crew member applying the hand brake pushes a button, the electric motor winds the brake chain to a predetermined tension, and stops. The reverse process releases the hand brake. Small lights indicate whether the hand brake is applied or released.
There are several different types of these electric hand brakes. They operate in different ways. Some were truck mounted, some attached to a more normal looking handbrake wheel and some were made to fit the older style ratchet type. The ones made to fit the ratchet type were the best. They were quick to wind up and released in an instant. Boy did these things save a ton of jacking up and down!
On the other hand, with the other two types of electric brakes, if you had the need to stop a locomotive that was moving, you might as well forget it! The loco would run away before those snail paced things tightened up against the wheel!
Possibly the first was on Conrail’s SD80MAC fleet starting in 1995.
