Country Area ‘Merlin’ MB
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Click here to see brief notes about this vehicle and technical notes about this particular drawing >>


Notes About This Vehicle

Despite a long and illustrious history of in-house bus design by London Transport and its predecessors, radical changes were on the way by the mid-1960s. The delivery of new Routemasters finally came to an end in 1968 but by then London streets were already home to what some called ‘off-the-peg’ vehicles.
Further changes were also taking place with the introduction of one-man-operated (OMO) buses. Experiments with one-man operation were not new, though designing a bus purely intended to operate in central London in this way, as opposed to converted vehicles and failed bespoke experiments, were.
1965 saw 15 AEC ‘Swift’ chassis with Strachan bodies, 36ft 0ins long, with front entrances and centre exits arrive; these were eventually called ‘Merlin’. The first six were XMS fleet numbered 1 to 6 and were in central area red. A further nine were delivered in country area green with a different internal layout and fleet numbered in the series XMB 1 to 9. Eight of the nine XMBs had not yet entered service and were converted to XMS layout. XMBs 2 to 9 were re-numbered XMS 7 to 14 and XMB1 was later re-numbered XMB15.
The first XMS entered service in April 1966 on Red Arrow route 500. The Red Arrow was to become a branded network all of its own with a flat fare and very limited intermediate stops. Passengers entered at the front and paid via a coin-in-the-slot and then pushed through one of two three-armed turnstiles. Exit was via the centre doors. One-man operation, flat fares, and separate entrance/exit are all routine now, but these were significant innovations then.
A further major departure was a severely reduced seating capacity of 25 and with up to 48 passengers standing, though this varied according to differing internal layouts that followed for similar vehicles in different, but related, fleet designated series.
Following the experimental 15 vehicles, a further 150 Merlins were ordered. These were to a more elegant external design with bodies from long-standing supplier to London Transport, Metro Cammell Weymann. Although for different applications and with different internal configurations, they formed one series of fleet numbers.
MBAs 16 to 31 were for the Red Arrow routes; MBSs 32 to 80 were for suburban flat fare routes; MBs 81 to 113 were for country area OMO; MBs 114 to 165 were central area equivalents and oddly had no centre exit doors.
Deliveries commenced from February 1968 with MBA18 appearing on Red Arrow 500. Country area MBs 81 to 113 were received by the end of February 1968. As depicted in this drawing, the batch of 33 MBs only appeared in this green London Transport livery for about two years, before the country area routes were transferred to the newly formed London Country Bus Services as part of the National Bus Company.
Further deliveries arrived rapidly, almost too rapidly bearing in mind there was so much new about these buses and that they had not really been tested in anger. There were several consequences of this.
The fleet numbers allocated were: MBAs 166 to 193 for Red Arrows; MBSs 194 to 269 in red for suburban flat fare routes; MBSs 270 to 303 country area OMO; MBs 304 to 397 central area equivalents; MBSs 398 to 438 country area OMO; MBSs 439 to 615 suburban flat fare; MBs 616 to 665 central area conventional OMO and to the same door arrangement as MB304 to 397.
There were many complaints from drivers about the early vehicles that the seating position was too low. Red Arrow MBAs fleet numbered 166 to 193 had a higher driving position, though the original lower one, and associated offside cab window, are depicted in this drawing. In due course MBSs 550 to 559 were built as new as driver front entrance and centre door self-service.
A further complexity in trying to follow the history of the usage of these buses occurred when thirteen MBSs were converted to MBAs in 1974; ironically, this was the same year as the first withdrawals of the series.
Unfortunately these buses were not particularly well put together and had a justifiable reputation for rattling profusely. They suffered several mechanical and structural faults – some of which were quite serious with roof domes coming apart and windows popping out. Some structural strengthening was carried out to remedy these from 1969 and these are included on the bodywork in this drawing.
As a result of complaints from drivers that this series of buses were too long, the next generation of SMs and SMSs were shorter at 33ft 5ins.
Today these good looking buses are possibly regarded with rather more affection. Not especially loved in their day, only a few survive in preservation.

Notes About This Drawing

The drawing is based on a general arrangement of transfers drawing ‘MB.003 R.’ from 1979. This type of black & white sketch drawing, as implied by the name, is not intended to define detail but as a specification guide to builders.
All the fine detail has been interpreted from a few black & white images from 1968, and colour ones of MB90 in July 2018, when in an advanced state of restoration, though still awaiting some of its transfers. The detail should not be viewed with any certainty in terms of its appearance when in service and none of it can be regarded as definitive.
It should be understood that all four elevations are seen here as one would see each part of the vehicle at a truly perpendicular angle. In real life this is of course impossible.


I would like to say a ‘thank you’ to Peter Comfort for his assistance with some of the fine detail depicted in this drawing.
© drawing copyright Douglas Rose – January 2019
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