Well, in the link, LR timing ranges from 0 minutes (Sep 08) to 40 mins (Aug 25) along with various miscellaneous data!!
Further, to take off air from vacuum brake & take loco off plus forward move to get on different track & backward move to get on track to merge with same line @ Rake end & then move to back of rake & then joining Loco along with air fill in vacuum brake & afterwards signing ok for no problem in braking from this side.....all this take time (above 20 minutes & if done quite fast, then too will take 25-30 minutes)!!
Yeah,...
more... train accelerates but train with LR & without LR will get different scope of slack timing (without LR would get no slack even for same stretch)!! Plus, train dont always arrive right time & slack consider this even & thats the reason for LKU-BE been 2 hrs 45 mins while BE to LKU is 3 hrs 30 mins run!!