You're welcome pdxrailtransit. All of the trainset except for the caboose behind the 105 was comprised of pre-WWI ex-Oregon Electric Railway interurban coaches which were all connected with large safety chains because the tip-over on the vertical curve was so sharp that the coupler knuckles would come within scary distances of slipping by and causing a train separation.
There was a wye at Vernonia but none at the Banks home terminal so at Vernonia the 105 was run around the train (in the early years 6-car operation as illustrated in this photo) or a drop was made (in the later years 9-car operation) which put the 105 running with the smokebox next to the open car on the return trip. Almost always the SP&S Portland extra board engineer chose to run Banks to Vernonia and would trade sides of the cab for the return trip. At the summit coming off of the 1.5% onto the 8% up to the tip-over the railfans in the open car would go nuts as with the 105 wide open and in the corner I pinched the speed down with the straight air to nearly two seconds per exhaust (which was much slower than the 5 MPH speed limit at that location) making it appear as though we might not make the hill. The ruse backfired on me one time when some prankster greased the rail.
[img]http://s1317.photobucket.com/user/700Jim/media/Photos%20for%20discussion%20threads/VSPampSonSPampSVernoniaBranchbridge401-800x544_zpsa4e96714.jpg.html]