The class 321s

The class 321s are a newer design of EMU than the class 310 and were built by BREL York in 1987. The 321s are capable of 100mph and are divided into 3 sub-classes:

321/3- 4-car units for GE main line.

321/4- 4-car units for WCML local lines to Northampton.

321/9- 4-car units for services around Leeds.

Also, there are three other classes of EMU that are very closely related to the 321s:

320: 3 car units for Scotland services.

322: 4 car units originally for stanstead airport services, then Scotland, now GE.

456: 2 car 3^rd rail units for network southeast. (Later connex south central).