Newman Atkinson says:

Couplers on the front end of any Steam engine: Those couplers are there to double head a train and in the case of switching that engine could switch or break a train as necessary if nothing else was available. Although the big steam was used in route or long hauls, it was used in yards to pull another engine not fired up into a shed or engine house and like I said an occasional switching. Even itself might need to be pulled in the engine house (or pushed in after it has been cooled down) The drawback to using the large steam was the sharp curves off the main line and caution had to be used where and when. Also in some cases the engine might have been used in a backwards configuration where it was difficult to turn the engine for a turn around or leg of a trip. A case in point The UP did not turn their passenger cars at Denver a dead end terminal at that time, to go north to Cheyenne, Wyoming Then at Cheyenne they would move the engines back to the other end for the rest of the route. The same could apply to the engines if there was no turn around or wye. My experience was with the Diesel F-7’s and we road in the coach on that stretch backwards. Although the Big steam could do that, the big tenders made it difficult to see Although I don’t think the view is the best going forward either. When operating your model railroad and you want to put another steam engine in the engine house, it would look good to have another push or pull it in or out or at least make it look like you did..
In Ft Wayne NKP 765 is cooled down outside the shed and a diesel is used to pull it in and out. The reason is there is no smoke exhaust or ash pits in the shed and need to keep the engine house clean to work in. Newman Atkinson Terre Haute, Indiana