We are welding bridge girders and the question came up about welding of the flanges to the web.  In general we use a tractor sub arc to make the weld but to start the weld we have to start approx. 1 foot in from the end of the girder.  We then comeback and use handheld SAW to weld the remainder that could not be welded with the tractor.  My question is, is there any particular welding progression that needs to be followed when making that weld (such as welding from the end of the girder in towards the start of the tractor weld or must we weld from the start of the tractor weld out to the end of the girder?)  Please respond.