Thursday, May 19, 2016

That Hissing Sound

On Wednesday we started on inspection for the 308, seen here poking its nose out the door.  We ran into some annoying problems.  It's nothing we can't fix, but more work needs to be done.

The traction motors appear to be fine.  Here we are looking straight up at the commutator.  On the left, you can see a small part of the lower field coil.

The cut-out cocks under the motorman's valves tend to develop leaks over the years.  That hissing sound you hear is not just annoying, it makes the compressor work harder and affects the control of the brakes.  On the 308, we decided the #1 end needed to be fixed.  It looks here like something's missing.

Dan Mulvihill was helping us again, and he put in a lot of effort to repair the leaking valve.

This is what the disassembled mechanism looks like.  If the valve body and the chamber are not both perfectly conical, air leaks out.  Hisssssssss....

Meanwhile, Gerry Dettloff and John Faulhaber are getting close to getting the brake system working on the LSE boxcar.   Seen here, from left to right the brake cylinder, auxiliary reservoir, and K triple valve are all one assembly.  The system was tested on shop air, and the cylinder moves!

Despite our best efforts, the 308's cutout could not be repaired to anyone's satisfaction, so a new valve has been installed.  And the hissing is gone.  As seen here, it may be somewhat of an eyesore, but by removing the yellow rubber and painting everything blue, it will blend right in.  You'll see.

Thanks to Dan for helping all day; Rod provided the new valve, made new gaskets for the unions, modified the handle, and assisted as always with expert advice.

1 comment:

Joe S. said...

I have fought with those cut-out cocks many times over the years. It would be great to try and keep the original valves, but we can't do that. They depend on a brass on brass surface being lapped just right. Eventually, the brass wears out to the point where you just can't lap them anymore. They don't make these valves anymore either, so the choice is try to have new parts cast, or use a modern cut-out cock.