Position will be like "Loco-slr-coaches-slr. In the last SLR , the guard's cabin should be at end position.
In return trip, if the single SLR taken to last position, the guard's position will be at the front end of the last SLR., which is not advisable.It should be at back end of last SLR.
So they keep 2 slr for each train.
In...
more... this pic, "A" is the guard's position.