Following the negative reaction in some quarters to earlier EMUs built in the 1980s the Class 321 had a deal of attention paid to its external appearance with the aim to produce a train "eye catching" on the outside and comfortable on the inside .
|Number built:||468 (117 4-car units)|
|Motor:||4 Brush TM2141B traction motors (25kV AC OHLE)|
|Power:||1, 438 hp (1, 072 kW)|
|Formation:||(321/3) Driving Trailer Composite Open (DTCO)+Motor Standard
Open (MSO)+Trailer Standard Open Lavatory (TSOL)+
Driving Trailer Standard Open (DTSO)
The original NSE batch became known as the 321/3 with the London Midland batch the 321/4 (they have more first class seats than the 321/3s ) and the Yorkshire units 321/9. Unlike the other sub-classes these units did not have first class seating and so had 2 DTSOs instead of a DTCO and a DTSO.
321/3s still work on the Great Eastern route, thirty of the units are receiving a "Renatus" refurbishment and upgrade which includes new air conditioning, seating and wi-fi. Some 321/4s have been transferred to bolster the 321/3 fleet. The Class 321 may also be fitted to test hydrogen fuel cells.
Class 321s are currently operated by Greater Anglia and Northern. Both fleets are due for replacement by new build EMUs at the end of the decade.
|Greater Anglia 321 434 and 339 at London Liverpool Street|
|Inside a Greater Anglia 321|
|Greater Anglia (but in Great Northern livery) 321 408 at Romford|
|321 408 heads off Colchester bound|
|Renatus refurbished 321 at Southend Victoria|
|Greater Anglia 321 339 at Stratford|
 David Lawrence, British Rail Designed 1948-97 (Ian Allan, 2016) p. 236
 Alec Swain, Overhead Line Electric Multiple Units (Ian Allan, 1990) p. 76
 John Glover, Eastern Electric (Ian Allan, 2001) p. 131