All DMU vehicles normaly carried data panels on the No.2 end of the vehicle. This meant it was the inner ends in a set formation, but as single cars had no 'inner end' the data panels are more prominent than on other types. The No.2 end on a bubble car is the brake van end with the exhausts. Some carried data on both ends some of the time.
Here we look at how these changed over the years. This is just a summary of what I've found rather than an exhaustive list, and are will be other variations, each works, depot and even individual painter could have their own styles. The quality of the images varies, as these have been enlarged from a mixture of sources.
At least the first vehicle delivered - 55020 - had the ATC information painted under the data on the cab corner. For an example image see the Summer 1961 DMU ABC page 34. The more standard position for this was on the buffer beam.
This is 55027 in September 1961, with the vehicle being almost one year old.
Note that the text includes the new date - 22 - (10 or 11?) - 60
This is 55020 in April 1965. Other vehicles in this livery had the three groups of text at various levels.
An unknown vehicle. The style is very similar to that of the green / yellow panel era.
55033, undated. Identical style to that used on the Class 122s in plain blue livery. On the opposite cab side is hand painted the shopping proposal date. The set number is in Gill Sans font.
55025 taken in April 1981. It carries an unusual data sticker. Also noted on 55033 in the 1980/1 period.
55026 taken in 1983. The black sticker has metric measurements and the shopping and lifted details are hand painted near the bottom. At least 55028/9/30/2/3 were similarly adorned while in blue/grey livery. On the opposite cab side is hand painted 'S.P. 1.84'.
55020 taken in 1986. The black text is in the style carried over from plain blue livery days, without the MBS in the centre.
This is 975659 (ex-55035) in August 1990. This is the No.1 end.
55021 taken on 24/8/88. A modern data sticker which includes the design code.
55027 taken on 21/8/93. A variation on the above, with no 'D' in the vehicle type. 55031 has also been noted with an identical style in 1993.
55028 taken on 16/8/89. The main difference is it carries a white C1.
55028 taken on 2/10/92. This is the No.1 end. At the time the vehicle also carried what could be best described as a 'supersized' set number! 55025 was also noted with similar info on the No.1 end in March 1989 (with a regular set number).
55031 taken on 13/4/91. The vehicle carries its second style of NSE livery, the band heights are different from the first. The data sticker appears to be blank. At the time the set number appears to be black with a white edge, below which it carried the name 'Rachel'. 55032 also carried a similar blank data sticker whilst in blue/grey in 1991, as did 55022 in 1987.
55022. Carrying a partially filled data sticker.
55027 taken in 1999. It seems the green has been painted around the lower text.
55029 taken in May 2000. It also seems the green has been painted around the text.
Midline liveried 55033 doesn't seem to have carried any data details, nor did retro-green 55023, or ATW 55032.
Summary
Description
Diagrams & Works Photos
Numbering & Driving Inst.
Liveries
Data Panels
Operations
Non-Passenger Use
Images
Details about the preserved Class 121 vehicles can be found here.