TRAIN HANDLING IN HUMP (KNOLL) & CRESTING GRADIENT
Starting of train on a hump or cresting grade There are no special requirements for starting on a hump or cresting grade. The starting procedure are the same as for starting the train on an ascending (up) grade. Zonal Railway Training Institute, Central Railway, Bhusawal ©AC Loco Simulator.
Negotiating Hump(knoll) gradient
i) Approach the hump with reduced power thus providing margin for power increase and for stretching the train as the locomotive starts up the hump. Increase power, if possible, to avoid bunching the slack at the leading end and maintain this stretch condition until the locomotive reaches the crest of the hump.
ii) As the locomotive passes the hump, and starts to pickup the speed the drawgear will tend to stretch out. To keep slack action to a minimum, reduce power to keep speed constant.
iii) Keep the slack action to a minimum by MP manipulation to suit loading on the train and the grade condition.
Negotiating crest grade
i) Changing of slack condition - the train slack is required to change from a stretch condition while ascending or approaching the crest to a bunch condition on the descending portion.
ii) Road knowledge - The Loco Pilot must be aware of the characteristics of terrain for adequate braking on the descending grade following the summit. Zonal Railway Training Institute, Central Railway, Bhusawal ©AC Loco Simulator.
iii) Maintain constant speed - as locomotive reaches the crest of grade, the Loco Pilot should attempt to maintain speed by reducing MP to relieve stress on couplers at the crest.
iv) Use of dynamic brake after a crest - A following down grade is long steep, the dynamic brake should be engaged after one half of the train has crested over the summit, the dynamic brakes should be engaged and carefully adjusted to control speed & gradually bunched the train.
v) Balancing a cresting grade - If the grade following the summit is a light descending grade, MP manipulation & dynamic brake may be used to control speed and train slack movement. If dynamic brake is not available, the train brake should be used in the same manner as for the descent of a light descending grade.
Stopping of train on a crest grade
i) Avoid drawgear stresses :- Take all efforts to avoid stopping of train on a cresting grade, for which the Loco Pilot must have a good knowledge of the location of all cresting grade. A stop of a train on a cresting grade can Zonal Railway Training Institute, Central Railway, Bhusawal ©AC Loco Simulator. 80 lead to excessive drawgear stress on the wagon at the crest while attempting to restart the train.
ii) Reducing drawgear stresses:- If a stop has to accomplish, do so in accordance with the stopping procedures for descending grades. When stopping on a cresting grade, always ensure that the brake application used to stop the train is the lightest possible thereby reducing drawgear forces particularly on the apex of the crest.
Stopping on a hump or knoll grade
Avoid Run-ins: -While stopping the train on a hump, extreme care must be taken that the brake application does not result in severe run-in. To avoid slack bunching on the hump or knoll, the train should be stopped in a stretched condition.
