Gull Wing Cab

What is the difference between a reqular cab and a gull wing? What is its purpose?

This is a spotting feature of BNSF Dash 9 locomotives originally purchased by the ATSF. The angled section of the roof directly above the side windows is concave (think about a McDonald's restaurant). All others have the usual 3-sided cab roof. I do not know its purpose, however. This probably seems anticlimactic when thinking of gull wing Mercedes of the '50's and applying that concept to a locomotive. I hope this helps.

It had something to do with roof clearance. At least that's what I heard.

I'm pretty sure that some of the Dash 8 units had the "gull wing" cab too.

As I recall, it was a clearance problem atn one particular coal loader at a mine served by ATSF. The "gull wing" (some railfan magazine published a full-page photo of a train led by a new Warbonnet C40-8W -- ?C41-8W? -- when ATSF ordered the first units with this option, and the accompanying text likened it to the "inverted gull wings" of the WW II "Corsair" fighter plane) design was introduced after ATSF's first widenose GE's (the B40-8W) but before the Dash-9, and became standard on later ATSF and then BNSF GE units. The clearance problem evidently isn't a big issue any more: the GE-owned GEVO demonstrators have the standard cab, and BNSF seems happy to host 30 of them!

I think it was the York Canyon Mine (in New Mexico) that had the clearance problem, IIRC.