Until earlier this year there were only two 450s booked to Weymouth in each direction, all early morning and only one ran through to Waterloo. The Poole stoppers are a mix of 450s and 444s. The reduction in 444 usage means that more 444s are being stabled in between the peaks with less 450s stabled, with the 450s running on old 444 diagrams. The 444 mileage had gone above the limit agreed with Siemens for the current maintenance contract, so a new one had to be negotiated. The price of the maintenance contract taking the higher mileage in to account was a lot more expensive than the current one as Siemens hiked the price because the current contract was unprofitable to them. SWT decided to stay on the current, more affordable contract which meant they had to reduce 444 mileage. The 450 fleet takes up the slack with extra mileage but it is still within the limits of the maintenance contract agreed with Siemens for the 450 fleet.