Re: arc headlights and dynamos - A bit more research

Posted by skip on
URL: http://c-sng-discussion-forum.254.s1.nabble.com/arc-headlights-and-dynamos-tp15165p15201.html

John Greenly wrote

Skip,

I just looked through the photos of #12 in Coleman, and I believe it did have a generator behind the air tank.  The photos are from 1921 when generators were universally in use.   In the photo on p.62  there are cables to that location and I think you can see the generator just peeking out behind the lower edge of the tank, and the tip of the exhaust pipe is just visible above the tank behind the bell actuator.  Look also at the photos of 21 and 22, for instance, p.74.  Those engines both definitely had generators by 1917-18, but they're invisible in photos from similar angles as the #12 photos, except the exhausts can be spotted more easily if you look closely.  What do you think?

Now that you've pointed it out, I'm seeing the headlight cable routed through the handrail on a number of engines!

Cheers,
John

Wow John, good eyes! I am not completely convinced, but there does seem to be something there. In particular, the metal frame that holds the tank on the #11 and #13 only extend back to the back edge of the tank. The picture of #12 does seem to show the frame extending a foot or so farther back than on the other two B3As and it could hold a small generator. In the past when I looked at the two tubes running back into the cab, I had casually and carelessly thought that they were the common steam hoses that are often wrapped around the dome to run steam out of the globe fitting typically on the front of the dome. You see that on a lot of the engines. But these lines don't run around the dome as I had thought. They do seem to run back into the cab where they would re-distribute the juice up the handrail conduit to the headlight.

Coincidentally, this fits with one other bit of evidence. You may recall that I did a #13 from a Key #22 a while back. It is lacking a bit, but for some odd reason I really like the little thing. It has become one of my favorites. It peaked my interest in the other two B3As and Christmas found a couple more Key #22s. So I am in the process of building the #11 and #12 so that the #13 doesn't get lonely without her sisters. The Faulhaber conversions and the rebuild of the gearing are complete and I am in the process of butchering all the boiler details. I spent a bit of time with the photos estimating camera positions and doing the trig to try to get the measurements as close as possible. And to my surprise, it seems that the air tank on the #12 is a foot or so forward of the position on the #11 and #13. Those two have the tank about 2/3 of the way back from the sand dome to the steam dome. The #12's tank seems to be about in the middle. The #12's position is not as far forward as the B3Bs but the #12's position does seem to be a bit different than the #11 and #13. Looking at the pictures with your suggestion, I am wondering if the shop put a generator between the tank and the steam dome like on the B3Bs? The general wisdom has always been that the #21 and #22 had the tank forward with a generator and the #11, #12, and #13 had the tank back with no generator. But now I am wondering...

You realize that you are really screwing up my latest project here. I just got done soldering the tank into its hopefully correct position on my new #12 and now I am wondering if I need to pull it off, extend the frame and add the generator. Oh well, that's the fun of digging into this stuff. So while I am cursing you under my breath, thanks a lot for the close look. I think you may be on to something here. Let's keep looking.

Skip Egdorf
Los Alamos, NM