On Tue, 17 Jul 2007 09:49:40 GMT, "www.waspies.net"
wrote:

wrote:
I always thought that it was because the driver had the controller in the
shunt position, which put a lot of energy through the resistor grids. When
the driver puts his controller back to coast after being in the
above-mentioned position, it is then that you hear the popping sound.

I could be wrong, of course, but I notice that this happens only when the
train's controller is apparently in shunt position. At least it feels like
that.
The popping noise is where the motors haven't had time to fully wind up
in ANY motoring position and are then taken off, the fact that the
Traction Brake Controller is in parallel makes no difference, the motors
accelerate through Series then into Parallel, I think that they don't
touch Shunt though due to the excessive heat generated in the resistors
(people who are better acquainted with C Stock will know this better
than me).



I've heard it a few times on SWT's 458's as it leaves a station.


Dave