Vehicles were powered with Rolls Royce C6 6 cylinder engines of 180hp, except M50136 which was fitted with a supercharged version producing 230hp, at least for a testing period. According to the BUT spare parts manuals the second batch were fitted with R14 gearboxes, normally only fitted to 150hp engined vehicles. The first / third batch had the SE4 gearbox which was normally fitted to mechanical transmission vehicles with larger than 150hp engines.
The image shows 50136 on trial with dynamotor vehicles.
The interiors of matched the contemporary Class 101s being produced. The 1959 cars had maroon seating in second class.
This image is from a Met-Camm publicity brochure - a rare colour interior photo, although probably a B&W pictures that was 'colourised'.
Three different cab fronts were used on this class.
The four LMR power/trailer 1957 sets had four marker lights.
The 3-car sets built in 1957 had two marker lights and a two-character train describer panel beneath the centre cab window.
In 1959 by the time the last 10 three-car sets were constructed the 4-character headcode box was mandatory. This headcode box was located above the driving cab windows where, due to its height and width a modification to the central cab window had to be made in order to accommodate the destination blind display. This involved fitting a smaller central cab window and lowering the destination box by 6 inches into what was the window space.
After headcodes were abandoned in January 1976 these boxes were eventually removed and the space plated over, returning these vehicles to the original style though the lowered destination display remained still making identification of this batch easy.
How do you tell a 111 from a 101 if it wasn't from the last batch? The next easiest identifier is the exhaust pipes. On the Rolls Royce engines the exhaust outlet was on the right side, on the BUT engines (Leyland or AEC) it came from the left. As seen in the two example images, the first shows a 111 non-drivers side, and the exhaust seems to come from behind the radiator, the second image shows a 101 which has a notably shorter exhaust. The radiator size also differs.
Differences in the battery box covers can also be seen, although this 111 type only seems to have been fitted to the first four sets. There also two upright cylinders between the battery boxes and radiator on a 111 - probably the fire extinguishers.
On the drivers side the reverse is true for the exhaust pipes, the 111s have a noticely shorter one and the radiator really seems to stand out.
After the success of an experiment conducted by Doncaster Works on Class 104s 50446/50521 in 1982, it was decided to remove one engine and its associated equipment from the remaining Class 111 motor cars as a maintenance and cost saving measure. Centre trailers were removed where necessary and redeployed in other units, after conversion the remaining power cars were paired together as power twins with just one engine per car they had a combined 360hp, half normal power but enough for the duties they were to perform.
These units were operated by Neville Hill (NL) depot in Leeds, and carried "Metro Train" and South Yorkshire PTE logos.
Vehicles treated remained in the blue and grey livery but were renumbered in the 78xxx number series. The vehicles involved were all from the two later batches, none of the four early power cars were converted.