(23 Jan 2016, 7:23 pm)tyresmoke wrote Each bus has to be tested every year, so these have to be spread across the year at each depot. You usually lose a bus for a week for preparation - test day at Stockton is on a Wednesday which usually sees one of our own, plus a vehicle from Redcar and two from Darlington all having MOT tests.

There are only around 50 weeks available to MOT test vehicles - with a fleet size of around 70 at Stockton, this means one or two are done each week. This means it has to be spread across the fleet so that we don't end up with 10 vehicles off in one week. I'd presume (I'm not 100%) that this means vehicles coming in will take the dates of vehicles leaving the fleet, to keep the yearly spread as close as possible to what it always has been.

But what about used vehicles that enter the fleet or transfer between depots? A used bus coming into the fleet may be due its annual test in the days or weeks after it arrives, but the bus it's replacing may be on the schedule to be tested several months into the future. Presumably each bus's MOT only lasts for 12 months and you couldn't run a bus without a valid MOT just to fit the depot's engineering schedule. 

I would imagine a second hand bus arriving would just have to continue on its old schedule so that its MOT doesn't lapse, or pass its MOT before it enters service, depending on circumstances at the depot with engineering / service requirements?

Clearly in the reverse situation where the bus being replaced is shortly due its test and the bus coming in still has several months to run on its MOT this isn't an issue, other than the potential cost of preparing and testing a bus soon after its already been tested.