Trivia: Unit class with the most amount of formations.

[stadler]

The class 222s have now been formed in six different lengths as they have been formed in 4/5/6/7/8/9 coach formations.

They built 143 carriages which have been reformed four separate times which has resulted in five different lots of formations and a total of six different unit lengths used in passenger service.

First Formations:
• 7x 9car (001 to 007)
• 16x 4car (008 to 023)
• 4x 4car (101 to 104)

Second Formations:
• 7x 8car (001 to 007)
• 3x 4car (008 to 010)
• 7x 5car (011 to 017)
• 6x 4car (018 to 023)
• 4x 4car (101 to 104)

Third Formations:
• 6x 7car (001 to 006)
• 17x 5car (007 to 023)
• 4x 4car (101 to 104)

Fourth Formations:
• 4x 7car (001 to 004)
• 19x 5car (005 to 023)
• 4x 5car (101 to 104)

Fifth Formations:
• 5x 6car (001 to 005)
• 18x 5car (006 to 023)
• 4x 5car (101 to 104)
• 3x 1car (spare carriages)

My question is whether any other units beat this? Has there been any other rolling stock class in history that has operated in six difference formation lengths or more? I am wondering if any older first generation DMU or EMU units might have done so as i know they were a lot easier to reform?

The closest i can think of in recent times are the 168 (2/3/4) / 171 (2/3/4) / 377 (3/4/5) / 378 (3/4/5) which have all operated in three formations each but that is still nothing compared to the six formations (4/5/6/7/8/9) that the 222s have had.

Note i am only talking about individual units on their own. I am not including multiple sets coupled together. Nor am i including locomotive hauled carriages which can run in any formation.

 

[pokemonsuper9]

One thought is what about certain Turbostars being converted to different types.
I'm not sure how often they have been swapped back and forth but 168/170/171/172 are pretty similar and they have had conversions between each (e.g. TPE 170s becoming Chiltern 168s, or Southern 171s becoming EMR 170s)

I'm not sure how we deal with sprinters for this matter
E.g. 153s had been 155s, then 153s, and on some occasions hybrids with a 150 carriage, and now the active travel units(on TfW with a small cab and a 155 cab at each of the true ends).
Not exactly different lengths, but certainly different consists.