This page created 27th December 2000, using Notepad, by Ian Smith.

The AEC Q in London

Q for Queer. The Q Type was an odd type, from the off-centre mid-placed engine that rotated the wrong way, through the lopsided suspension and the single rear tyres to its full-front, lack of front radiator, rounded profiles and extraordinary wheelbase. Some of these do not sound so odd now, but it was start of the nine-thirties. The Q type was the brain-child of John Rackham, head-hunted from Leyland by AEC. Well perhaps "brain-child" is a bit extreme, as much of the concept could be seen in the 1929 American Fageol "Twin Coach" idea. That had side-mounted engines amidships - TWO of them, one each side. Rackham's English version made do with a single engine, mounted behind the front wheels on the offside, and driving a transmission train mounted outside the offside chassis frame to a differential offset on the rear axle. This required single rear tyres. This could only be achieved by altering the weight distribution by moving the rear axle almost to the back of the bus. Even so, the tyres had to be larger and wider than normal.

With the rear axle moved right back, the traditional rear platform was displaced, either to a mid position opposite the engine or to the front, ahead of the front wheels. This was drastic redesign of the bus concept. The staircase on double-deckers went over the front wheelarch or the engine.

The full-front, still new even on trolleybuses, gave a "modern" look to the front, and was acceptable without the noise of an engine. Getting the Metropolitan Police to accept a full front was another problem: they were still fighting against the concept of windscreens on half-cabs!

Q83 at Cobham Museum, April 1998 Q83 at Cobham Museum, April 1998

The prototype, Q1, was trialled in a blaze of publicity in London, after which interest by the London General Omnibus Company was muted for a while. It was busy suffering a reorganisation - always a stifler of technical innovation - and was anyway wedded to the new AEC T family: the Regal T, Regent ST and Renown LT, that looked likely to fulfill its needs during the 1930s.

Interest resumed in 1934 with two pairs of double-decker prototypes, two each for London Transport's Central and Country Areas. Q2 and Q3, the Central Area doubledeckers, had front entrances and a gently curved style that would reach its real fruition in the RT class to follow.
Q4 and Q5, for the Country Area, had a power door amidships. The Central Area buses did not find much favour, and soon joined the Country pair for a perpheral existence until the war.

But in 1935 London Transport made the Q its standard single-decker bus, taking 100 4Q4 types with mid-doors for Country bus operations (followed later by another pair), and 80 5Q5 front entrance buses for the Central Area.

These were followed by Greenline coaches. The first was a six-wheeler double-decker, Q188, intended as the prototype of a fleet for the Romford services, but it was not to be. Q188 spent its short revenue-earning career with Lt on Country bus services. Not so the fifty 6Q6 coaches that followed, that had long careers as Greenline coaches before and after the war, and as ambulances during it. Some even had a final fling on Central Area bus duty.

The Qs (apart from the prototypes) had a decent length of service with LT, spanning from 1935 through the war years to the early fifties, when they were all displaced by the RF class, 6Q6s first, from Greenline work, then the Central Area 5Q5s and the 4Q4s (some of these displaced by ex-Greenline 10T10s).

All were sold to dealers, as by then London Transport was under nationalised bus company rules that prevented any sales to operators that might compete with BTC companies. Some were acquired by contractors for staff transport, and many went abroad, especially to the Mediterranean countries and islands.

Q83, RT593 at Cobham Museum, April 1999


  1. The prototype, Q1
  2. The Central double-deckers, Q2-3
  3. The Country double-deckers, Q4-5
  4. The Country buses, Q6-105, 186-187
  5. The Central buses, Q106-185
  6. The Greenline six-wheeler, Q188
  7. The Greenline coaches, Q189-238
  8. The Bus histories
  9. The photographic references

Ian's Bus Stop Q introduction. Q index. Q1