Re: Helper Engines Placement

I've been fumbling through my old timetables to try and find the specifics. Alamosa Division No. 125, dated June 1, 1949.
Rule 9-D. "K-36 and K-37 engines must not be double-headed over bridges 319.95 and 339.78,
Sub-Division 11."
Rule 9-5. "When second engine is used on trains of over 35 cars on Sub-Division 11 between Antonito and Cumbres, second engine must be cut into train. When second engine is used on Sub-Division 12 (Chama-Durango), place it on head end"
Seems to me at some point the limit was stated in tons rather than cars.
Rule 9-I...."In operating three engine train out of Sargent or Chama eastbound use two engine on head end of train and one engine on rear end, the rear engine just ahead of caboose...."
I couldn't find anything about two engine trains Chama to Cumbres. But the practice in the 1960's was to cut the helper in ahead of the caboose.