...at least that's what it was called by an RyPN poster, presumably as a typo. But it's as good a description as any I could come up with on purpose.
Richard has studied this problem much more than I have, and he has several good points, of course. First of all, here's the door he referred to in a comment, and I didn't post it because I totally failed to see the earlier number. But that number agrees with the info I got from Frank's list. And who am I to question anything?
Next, here we are inside the compartment that used to hold the ignitrons. The crew had orders to check the ignitrons visually on a regular basis. Presumably you could tell by looking through the little windows whether the ignitrons were firing correctly. When the locomotive was rebuilt by Conrail and the ignitrons were replaced by silicon diodes (and what could be more boring than a silicon diode?) the windows were painted over with Conrail blue.
And if you need high-current silicon diodes, look no farther than Shorewood, of all places. For me, that's right down the road!
Richard and I were both crushed to learn that the ignitrons are long gone. Anyway, we will continue to study the evidence for historical purposes. And you'll read it here first, I hope.
Update: Mercury, the Winged Messenger
A friend sent me a PM about the ignitrons:
Be glad the mercury is long gone. It is a hazardous waste. When tearing down
an old lab wall at Buckeye Steel we found a quart milk bottle full of mercury
(corked). Seems it was used in pressure gauges on the open hearths which were
replaced by the arc furnace in 1965. The bottle was unbelievably heavy. We had
to pay to dispose of it as the liability to keep it was just too much. Cost
almost $1000 in 1998 and it looked like a Brinks truck that came to pick it up.
He makes a good point. In an ignitron, the mercury was encased in a chamber that had to withstand a controlled explosion 25 times a second, and it's highly unlikely the mercury could ever leak out. But regardless of one's opinion as to the actual danger, we have to obey current regulations as they are, and the Museum is no doubt better off not having to deal with a problem like this.
For what it's worth, George Elwood's rr-fallenflags.org has copies of the operator manual for the Pennsylvania E-44.
ReplyDeleteC Kronenwetter