The hot spares are allox each day, and certainly the Euston hot spare works the 1733 to Liverpool before being relieved 20 mins later by an EBW arrival, and as such are figured in the 47 sets. The working diagrams for each day show these.
The 5 390s that are not rostered each day are on full day maintenance or long period overhauls. The maintenance period through the night allows the first trains into shed out first, and the last ones to pick up workings mid morning - peak when they're running out of trains. There is also 2 diagrams that have peak morning workings then nothing until the evening and as such can be worked on during the day at Willesden and are extra spares.
There is 1 hot spare at Euston in a relief road usually, although it can shifted back to Willesden; 1 hot spare at Longsight. There is no hot spare at New St, however there is mid-afternoon turn which runs as necessary taking one of the London spares on maintenance to New St if the Oxley set under maintenance has had to step in.
47 diagrams including the hot spares, 2 allowed under heavy overhaul periods, 2 at Longsight and 1 somewhere else (Oxley or Polmadie) or all 3 at Longsight (Fri/Sat).
