Yeah I’ve noticed they take at least 2 745s off ps a week. I’m guessing for maintenance or tables being fitted to a 745/1, That being 745101 hasn’t shown on rtt for over a week, 745002 has recently gone back into ps after being off for about a week. If you count the 10 train diagram for Norwich & 9 for stansted over rtt, they only need to operate 18 745s 6 days a week with the spare being a triple traction on Norwich & a pair of 720s on stansted. On Sundays it’s different, Only 5/6 745s are needed for Norwich as regularly 1tph in which stansted can run a full house of 745s if engineering works don’t take place on the waml via Clapton. If another 745 had to be taken out of service if defected or maintenance, they would add on the extra 720 on stansted & the 10 car triple traction 755 on Norwich. Most of the time disruption on the line can cause diagrams to be out of place, etc if most 745s are between Colchester & Norwich during a points failure, fault with the signalling system to occur on the geml, they would not have to use an extra 720 to fill in for the few 745s that usually change over diagrams to stansted, mainly the 07:30, 09:00, 11:30, 14:00, 14:30 & 19:00 to Norwich use 3 different 745/1s. It’s a shame they didn’t order another 10 more 745s if they wanted to extend the timetable to 3 tph instead of 2 on Intercity.