Posted by Franz [64.24.149.61] on Thursday, October 03, 2013 at 00:42:01 :
In Reply to: Re: How do gin poles on a power wagon posted by Don Evans [67.53.104.82] on Wednesday, October 02, 2013 at 18:36:49 :
That isn't an A frame, it's a self erecting derrick.
It becomes a derrick when the stiff arm replaces a chain or cable gantry.