Short off-peak rakes - history query

[Lord of Narnia]

I note that the Hainault - Woodford shuttle has returned for the reasons stated however four car operation cannot start until perhaps March as the 1992 stock 4 car units do not have de-icing equipment! There has also been concerns that the shorter trains may get gapped on entry to Hainault depot on certain roads. 
 

This shows the complexity of running shorter trains which sometimes outweigh the rather obvious reasons for them. 
 

I remember many years ago now after the last Chesham shuttle ran but when there were still plenty of A stock left it was reinstated for a weekend during engineering works! The bay had to be restored and the conductor rails cleaned. Unit 5092-6092-6093-5093 performed the honours. Strangely unit 5090-6090-6091-5091 had performed the last official shuttle in 2010 before the timetable change! 
 

From a modelling point of view there are often opportunities to run shorter trains (apart from the fact it’s your layout and you can do what you want!) in engineering duties. For many years there was a four or five car Rail adhesion train (RAT) of A stock which is now formed of D stock on the Met. The Central line has a 5 and 8 car 1959/62 RAT and even the Piccadilly has two 3 car 1973 stock RATs now!