There have been previous mentions in these pages concerning the test trips made by LT trolleybus 1379 with the view, that after the proposed closure of the tramway, this useful subway could see continued use.
With the decision having been made in July 1939 to withdraw trams from the Subway, trolleybus 1379 was built to test the capabilty of trolleybuses to operate the replacement service. The additional work involved fitting air-operated jack knife doors of the off-side, moving the upper deck staircase forward to create an unobstructed platform, with a straight climb rather that the usual half-turn stairs. This conversion resulted in the loss of two seats, one on each deck.
During the early hours of Sunday 13th August 1939, 1379 made two return trips through the Subway. Both trips were made using battery power, the seating on the lower deck being removed to allow the fitting of extra batteries and additional air tanks for the air brakes. Both trips started at the Southampton Row (northern) end. See Matthew Geier's recent picture of the Southampton Row Subway entrance today, posted a week or so ago. When the trolleybus reached the Embankment end of the Subway, it turned under its own power and commenced its return journey.
The first return trip was made at dead-slow speed while clearances, which proved to be extremely tight in certain places, were checked. Before the return trip could be completed, the batteries became discharged, and the bus completed it's journey behind the diesel breakdown tender. Once under the wires, the bus ran under it's own power to Islington depot and return to recharge the batteries. The second return trip was to test the trolleybus running at service speed where possible. Again the batteries failed on the return trip and the trolleybus again had to be rescued.
About three week after the tests, Britain found itself at war, and all plans to scrap the tramway were withdrawn, and interest in a trolleybus replacement service just fizzled out. When the time arrived for the scrapping of the tramway in 1952, the Subway line just closed and was replaced by motor buses running on the streets above.
1379 was not reconverted back to a standard bus, and operated in it's Kingway form until it was scrapped in 1955. The off-side door was never used in service, and it's passengers probably didn't even observe that it was different.
Members wishing to read further on this event should try to get their hands on the book "Trolleybus" by Ken Blacker (Capital Transport Publishing. 1975) and the pamphlet "London's Tramway Subway" by the LRTL, a reprint of a series of articles from their "Modern Tramway" magazine.
A scan of a picture is shown below.
Don Campbell in Sydney.