The Metropolitan District Railway 1905 B stock was the second class of electric train to run on the line (after the prototype A stock of 1903). The MDR was part of the Underground Electric Railways of London Company Ltd from 1902, where the 'Underground' name was gained. It was nationalised with the other lines into the London Passenger Transport Board in 1933 and forever afterwards known as the District Line.
Following the success of the A stock an order for 420 cars of B stock was placed. The cars were built to a modified American design by Les Ateliers de Construction Du Nord de la France at Blanc Misseron, Pantin, Ivry, St. Denis and Luneville; Brush Electrical Engineering Co. at Loughborough and Metropolitan Amalgamated at Ashbury and Lancaster. The first service was on the 13th of June 1905. The design proved popular and the subsequent C and D stocks developed from it. In the 1920s some cars were rebuilt as H stock. None survived in service, or preservation, beyond the 1940s.
This was an interesting design to attempt to create in Lego due to the odd looking ends and the clerestory roofs. These were the first large class of electric multiple units in use in the UK so I thought them well worth attempting. In appearance they are identical (at this scale) to the C and D (not the current C and D) stocks which folloed them but I chose the B as it had not been reapplied in modern times and for the aforementioned reason.
The colouring was easy, but largely guesswork as all photographs of them are in black and white. Nevertheless the variation in shade suggested that the doors were varnished rather than painted (so brown) and the bodies would be the traditional red. Light grey made best sense for the roofs. As with the O stock model it is the trailer that is powered so that the bogies on the driving motor cars could carry the shoe-gear.