I think it's all East Midlands Trains depot drivers at Neville Hill - they used to be Maintrain. I think there are some 12 hour shifts. Would be mostly nights moving trains through the washer, getting them fuelled, moving them in and out of maintenance sheds, and preparing them for service. Not as many shifts would be required during the day, mostly moving trains in and out of sheds, but there may be the odd train needing fuelling etc.