The first unfortunate creatures in this category to hit the streets of London were the AEC Merlins in 1967. I use the term “unfortunate” because in my observations there really wasn’t much that was wrong with these buses, they were just the wrong type in the wrong place.
This was the result of a decision forced upon London Transport in the mid 1960’s by the government to buy “off the peg” models and save the cost of designing their own. The Merlin was a version of the AEC Swift chassis, admittedly not one of AEC’s most successful products, but it managed to find several satisfied operators elsewhere across the UK.
The London version came in three variants. Firstly the MB, a 36 ft long 50 seat single door bus to be used as a conventional driver only single decker. Perfect for the job so it would seem. A two door version was supplied to the country area, some replacing RT double deckers on town services, others replacing RF single deckers on rural routes. The trouble in all cases was that at 36 feet they were just too long for the roads along which they operated.
Next came the MBS, designed as high capacity people carriers with the emphasis on 34 standing passengers in the front section and seating only 32, mainly at the rear. Their intended use in the central area was on short hop local journeys and in the country area on town services with “Autofare” self service ticket machines where they soon became referred to as “cattle trucks”, especially after the Autofare machines were removed and the MBSs found their way onto longer rural or trunk services where again their length, along with their minimal seating capacity proved problematical and unpopular.
Finally, the MBA class to which I’ll return shortly.
The Merlins were somehow dogged by unreliability and were unpopular with garage staff. But then, for many LT engineering staff at the time if it wasn’t an RT, an RF or a Routemaster and couldn’t be dealt with easily at their Aldenham or Chiswick works then it simply didn’t stand a chance. I’ve also been told that where they were used on routes converting to driver only operation the timetables were not altered to take in the extra boarding time for fare collection and the vehicles had to be “thrashed” to maintain timekeeping
So, back to the MBA class, built for and run exclusively on the central area RED ARROW express services, linking several London main line rail termini with shopping or business areas. Although seating only 25 at the rear, the vast space at the front providing standing room for 48 made them the most perfect inner city people carriers of their time and the RED ARROW services were an instant success. The MBAs seemed to thrive on these services, especially on route 500 where for nearly twelve years they whizzed passengers up and down Park Lane on a punishing schedule between Victoria and Oxford Street, not bad for a supposedly unreliable vehicle!
The 36 feet length problem was addressed when a shorter version of the Merlins, the SM/SMS classes arrived in 1970 but like the MBs were similarly deployed where they couldn’t fit in. LT just didn’t like them. By this time double deckers were back in fashion and the notorious DMS arrived to be loathed just as much as the Merlins and dogged with the same unreliability. But these were Daimler Fleetlines, they worked perfectly well in other cities so why not London?
My gut feeling is that it’s simply because they weren’t an RT or a Routemaster………