A stock RAT trains over the years....

Autumn -

1986 Unit 5062
1987 Unit 5120 (with 5209 at other end)
1988 Unit 5120 (with 5209 at other end)
1989 Unit 5120 (with 5209 at other end)
1990 Unit 5096
1991 Unit 5098
1992 Unit 5120 (with 5209 at other end) 5209 was renumbered 5121 March 1993
1993 Unit 5108
1994 Unit 5110
1995 Unit 5094
1996 Unit 5100
1997 Unit 5102
1998 Unit 5108
1999 Unit 5110
2000 Unit 5108
2001 Unit 5108
2002 Unit 5108
2003 Unit 5232

These were all 5-cars.

The following were 4-cars

2004 Unit 5232
2005 Unit 5232
2006 Unit 5232
2007 Unit 5232
2008 Unit 5066
2009 Unit 5062
2010 Unit 5066

Then 5-cars again, 5234 both 2011 and 2012

When 4-cars operated the even-numbered trailer was removed.

No not quite. Due to the large numbers of spare A stock, 5036-6036-6037-5037 were stored out of service and robbed for spares from 1977. The opportunity was taken to convert trailer 6036 into a special sandite trailer. The hoppers to carry the equipment were permanent and the car never ran in service again. 5036-6037-5037 however were brought back to life and combined with spare trailer 6116 to reform unit 5116 for service. I think this was used to cover for A stock refurbishment (5034-6008-6009-5009) were also resurrected but refurbed along with 5173 to form the first refurbished train.

Initially, a 5 car unit was used but this was found to be underpowered and as Reg says the four formation was used. The even number trailer was removed and stored in season. The sandite car (6036) had compressors and air reservoirs etc. and for the purposes of the formation was just like a normal trailer.

Hope this help.

Thanks Reg for the list, looks like I may be building unit 5232.....

That date eludes me at the moment but probably during the maroon roof era - i.e. 1987-88.

However, it (6036) went by road for 'refurbishment' in February 1996.

Edit: The car was painted white with a maroon roof "after the 1986 season" which would make it early 1987 when it was removed from the rest of the unit (5062), which was before Neasden depot began overhauls. It was done as a trial to see what it would look like, with Neasden overhauls looming up.