The D78 is of course the train most usually associated with the District Line.
Apart from the Edgware Road service, these trains form the rest of the trains used on the line.
They are very reliable - the number of defects is remarkably low - but, as has been said elsewhere, they are overdue for refurbishment. Hopefully this programme will begin without much further delay!
In the current age of 'Corporate Livery' they are now the odd man out - still running around in their natural aluminium finish - and many people assume that they are much older than they actually are.
The following is a selection of pictures - mainly of the technical aspects of the train - again taken to order.