What Does RT Stand For

What Does RT Stand For

Quick question, what does RT stand for on one type of London Transport bus.


31/05/14 - 14:12

I think is was for 'Regent Type'

Roger Broughton

02/06/14 - 07:12

There has long been conjecture about the 'meaning' of the letters RT. The sometimes offered idea that it stands for Regent Three fails to hold up, as that chassis designation was not applied until the post war period, and the pioneer 150 examples of the 'pre war' RT ( though all but eleven were actually delivered to London Transport in 1940) were designated O661 like other Regents of the time. All true Regent IIIs were classified O961. Another suggestion for RT follows the reasoning that the classification fell into the pattern established by previous types. Thus the single deck T in its shortened double deck form was the ST (short T), which, when subsequently lengthened, became the STL (short T long). An updated design on similar principles then emerged as the Revised, Redesigned or Re-engineered T - hence RT. The often accepted explanation that the letters stand for Regent Type is surely weakened by the fact that the first London Transport Regents were STs and then STLs delivered from 1930 onwards. They were all 'Regent Types'. The definitive answer to the question will probably never be found.

Roger Cox

03/06/14 - 07:38

I prefer to hold to the Regent Three RT theory. This is consistent with other designations of the time, e.g. Regal Four (RF), Regal Four Wide (RFW), Regent Low Height (RLH), etc.
I hadn't heard about the designation Three arriving on the scene until after the Second World War. But so what? If the predecessor was known as a Regent Two, it would still have been RT, so the case against is 'Not Proven', as a judge might say.

Peter Murnaghan

03/06/14 - 11:20

I was given to understand, many years ago, by someone who, in some areas, was more knowledgeable than myself, that 'RT' was simply a contraction of 'Regent'.
I don't think that 'Regent Three' can be possible, since, when the RT was introduced, there wasn't even a Regent II.
I believe it is well documented that 'ST' and 'LT' stood for 'Short Type' and 'Long Type' respectively, rather than being progressions from 'T', so that sort of scuppers the 'Revised/Redesigned/Re-engineered T' theory.
Btw, what is 'T' purported to stand for?

David Call

03/06/14 - 12:58

..and STL was said to stand for Short Type Lengthened.
But I've never seen anything in print stating that any LGOC/LPTB paperwork ever supported these thoughts, so I feel it's all conjecture, which is always interesting in itself, of course!
Certainly the LTC could never have stood for Long Type coach, as it was the LT chassis shortened!

Chris Hebbron

04/06/14 - 07:49

I fear that Peter Murnaghan attributes a degree of logic to the London Transport classifications that was not there. As David Call endorses, the Regent Three model name simply did not exist in 1937 when the RT was originally conceived. The LPTB came into being in 1933 with a remit to rationalise and upgrade public transport provision in the Capital, and it proceeded to do with supreme confidence and élan. The RT model was conceived as a purely LPTB venture to update and develop the Regent to meet the anticipated surge in demand for surface public transport in London. The huge investment in Underground stock and buildings proceeded at the same time. Possibly the letters did stand for RegenT, as if the new organisation was setting the transport engineering clock back to zero. The post war classification scheme is not as straightforward as Peter Murnaghan suggests. RF stood for 'Regal Flat', just as the pre war TF meant 'T Flat' or 'Tiger Flat'. A TF contemporary was the CR which stood for 'Cub Rear'. The second letter denoted the engine position in such cases. However, the scheme sometimes tripped itself up and had to be compromised as time went on. The Leyland version of the STL could not be called the STLL as this was too cumbersome, so an amalgam of ST and the Leyland TD name emerged as STD. The RTL was a 'Leyland RT', not a longer RT version. The RFW was, indeed, a wider variant of the RF, but the RW was not a wider variant of the Reliance, as the 8 foot width was an industry standard by that time - it simply signified 8 feet wide, though why this should have mattered when London was buzzing with a fleet of 8 feet wide RMs, not RMWs, is unclear. I believe that GS stood for Guy Small, not Guy Special, because the G letter had already been adopted for the Arab. I anticipate some debate arising from some of the above, but that is what OBP is all about. Finally, in answer to David Call's query, the 'T' class code for the Regal arose simply because it was the next letter after the previous 'S' type. That point, at least is definite.

Roger Cox

04/06/14 - 07:50

I would like to quote from p149 of Alan Townsin's book 'Blue Triangle'
"It had been announced in March (1945), when even the war in Europe was still on, that a small number of AEC buses would be available under the wartime allocation system and the models to be made available would be the Regent Mark II model with 7.7-litre engine and later the Regent Mark III RT-type, as it had become known. The reference to Mark III in this context had first occurred around 1941."
So it seems to me that while the first 150 RT's were in service by 1941 perhaps someone within the RT design team may have had Regent Mark III in there mind as the prototype was coming together in the late 1930's and was able to influence the designation RT. That is just a thought on my part, and of course it is highly likely we will never know the real reason for becoming known as RT.

Eric Bawden

04/06/14 - 17:46

In responding to my earlier conjecture, Roger has taken us beyond the RT era into the 1960s with the three RWs, one of which which I remember travelling on to Earlswood Lakes on the 440 from Caterham, as a young lad. I remember the novelty of the middle door and the lightness of the saloon, thanks to the cantrail windows - such novelties for LT buses of the time.
But, as Roger says, by that time 8 foot width was commonplace, so the W won't have denoted the width of these Reliances. I have always held that the classification of these three buses was to signify their Willowbrook bodies.

Peter Murnaghan

05/06/14 - 07:20

You could well be right about the RW code, Peter, in which case it further serves to underline the inconsistencies within the LT classification 'system'. We would be misleading ourselves if we believed that the Chiswick engineers had a proper formula for their codes. Incidentally, I, too, remember the RW buses well, as I worked at LT (CB&C) Reigate Divisional Office for a number of years from 1960 before moving to Halifax. On the matter of the meaning of the ST code, the "Short Type" interpretation surely does not withstand scrutiny. The previous LGOC volume production double deck was the NS, itself a code that has led to at least three alternative interpretations- New S, No Step or Nulli Secundus. The NS had a wheelbase of 15ft 6ins, whereas the wheelbase of the later ST was 15 ft 6½, hardly, therefore, a "Short Type" in the context of its predecessors. If 'T' stood for "Type" then the allocation of that single letter to the Regal was singularly meaningless. The Chiswick determined type codes for Rackhams new Regal/Regent/Renown family took the 17ft wheelbase Regal for the core code, giving it the letter 'T' in succession to the 'S', which was the quantity produced standard LGOC single decker that preceded it. The shorter Regent then became the "Short T" and the 16ft 6ins (18ft 7ins for the single decker) wheelbase Renown became the "Long T". Eric Bawden has quoted from Alan Townsin's 'Blue Triangle' book, so I will do likewise. "Illogically, it had been decided that the Regal would be counted as the 'basic' T type, and the shorter Regent would be ST and the longer Renown would be LT." Staying with Eric's point about the Regent III, 1941 was four years after the original RT drawings and two years after the first RT test chassis had taken to the road. Also, anyone who has worked within the utterly introverted London Transport empire will know that it took absolutely no interest whatsoever in any aspect of bus operation by the so called "foreign operators" beyond its own borders. The idea that Chiswick would have condescended to concern itself with the nomenclature of models for AECs provincial customers is, I fear, not credible. Whatever 'RT' actually did stand for may never be known for certain, but I remain convinced that it did not originally stand for Regent Three. This 'Quick question' has generated some extensive comment!

Roger Cox

20/05/17 - 07:03

My memory of an Ian Allan or similar publication in the 1940s gave the "T" designation simply as "type". Hence STL (short type long), RT (route type), LT (long type) and so on. I was never very deeply into buses, more a steam loco fancier, but then I discovered girls...

Tony Evans

21/05/17 - 09:37

Sorry, Tony, but, as I have pointed out in a previous comment, the letter 'T' for "type" does not stand up. LGOC/LPTB had 798 examples of AEC Regals that they called the 'T' class. It is hardly likely that this meant "Type type". The letter 'T' followed the letter 'S' in the LGOC single deck sequence, and as the next generation of double deckers, Regents and Renowns, were variants of the same basic engineering design as the Regal, the ST, LT and STL classifications evolved from there.

Roger Cox



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