Good morning,

I am looking into repairing some rust damage of our GP9's short hood. After 70 years of a leaking steam generator and sand accumulation, the lower portion of the short hood has rotted out.

It is seen clearly in this photo, right under the SP.

http://www.rrpicturearchives.net/showPi ... id=3560939

The portion in question is not part of the sheet metal that makes up the majority of the nose, but in fact looks like some sort of channel to which the rest of the nose is bolted to from the inside. I can't tell if it is a standard structural shape or custom formed steel.

Does anyone have any structural drawings of this area, or offer any tips to steel repair in this area? Photos are greatly appreciated.

Howard Wise at Niles Canyon Ry. would know, he (with help) bought and restored SP 5623 (later 3189, five behind your unit), which also had a steam generator:
http://www.trainweb.org/sp5623/
https://www.ncry.org/about/collection/d ... ific-5623/

See here specifically:
http://www.trainweb.org/sp5623/repair.htm

"Before heading to Railfair '99, I decided to tackle a job that should have been done back in 1994 when we repainted. The two curved pieces on either side of the nose had been rotted out by the steam generator leaking and by 1999, they really looked bad. So, off they came with the help of an air chisel and the good old Makita grinder. New pieces were cut and formed by our favorite sheet metal shop, temporarily screwed into place to keep them tight, and then welded. Once welded in place, the screws were removed and the holes plug welded shut. The open areas to the left and right of the center are the access hatches to the number 1 traction motor blower and, on most early geeps, provide access to the sander valves. The Red material taped to the nose in the third view is a heat shield which prevents sparks from ruining the paint. The green paint in photo number 4 is the Dupont self-etching primer I spoke of elsewhere. Finally, after I repainted the silver on the lower part of the nose, Brian Wise gave the entire undercarriage a fresh coat of Centari."