Re: arc headlights and dynamos - A bit more research

Posted by John Greenly on Jan 29, 2020; 2:11pm
URL: http://c-sng-discussion-forum.254.s1.nabble.com/arc-headlights-and-dynamos-tp15165p15207.html

Hi Todd,

thanks for finding the DPL scan of this photo!!  I wish you did have a good side-on photo of your On3 #12.   Would you post the head-on view? It'd be fun to see.


Skip,
since we're being picky, here's a bigger enlargement from the DPL scan:



The red lines show the positions of the dome centers and the tank center.  It is clear that the tank is well forward of center between the domes.  Measuring these distances and taking into account the perspective  (the distance is foreshortened as you move further back away from the camera) you find that the distances are in proportion about 5:9, so 5 units of distance from sand dome to tank, and 9 from tank to steam dome.  That agrees well with the same measurements on the photo of #21 on p. 71 Coleman (also in DPL).  

Also note the position of the forward foot of the tank/generator mounting bracket bar, as indicated by the white arrows.  It's very close to the sand dome base.  Again, the same as on #21.  I didn't mark it, but the rear foot is likewise very close to the steam dome, again like #21.

I agree with your assessment that the rearward position of the turbine generator was best,  the short steam line would minimize condensation problems.  Probably #12 had its generator installed after experience had proved this.

Cheers,
John