United Automobile – Bristol SU – AHN 901B – S1

United Automobile - Bristol SU - AHN 901B - S1

United Automobile Services
Bristol SUL4A

The Bristol SU series had a limited following amongst THC Companies. This example is in Ripon Bus Station in July 1968 about to set out on the lengthy run to Masham. I would imagine the Albion 4cyl engine would be quite noisy although probably not as bad as the Gardner 4LK as fitted to the earlier SC series.

Photograph and Copy contributed by Ian Wild


Newcastle Corporation – AEC Regent III – KVK 986 – 86

Newcastle Corporation - AEC Regent III - KVK 986 - 86
Copyright Unknown

Newcastle Corporation - AEC Regent III - KVK 986 - 86
Copyright Unknown

Newcastle Corporation
AEC Regent III
Roe H31/25R

Before the D.V.L.A. It seems to have been common practice that local authorities would issue registrations to bus companies En-block which would then be allocated as and when required, as a result, vehicles which were two or three years apart could have registrations which were numerically quite close. Unfortunately, I do not have access to their fleet records, but Newcastle Corporation would seem to be a good example of this. Newcastle registrations were BB – TN or VK. Post war motor vehicles were AEC, Daimler and the all Leyland Titans, bodies came from a number of sources including, Massey. MCW. Northern Coachbuilders, Park Royal Vehicles, Roe and Weymann, then of course there was the trolleybus fleet. I am speculating here, but it would appear they had most of the registrations between KVK 950 or thereabouts, and LVK 140 ish, but they were allocated between 1947 and 1949. My information suggests that among that number were three 1947 AEC Regent III with H31/25R Roe bodies KVK 984/6 – 84/6. Sorry, I don’t have any further details, I know Newcastle Corporation Transport had some pre-select Daimlers, but I’m inclined to think that these were a 7.7 litre with a crash box. 86 is shown here in its original 1947 blue, and again in the post 1949 yellow livery which had previously been the sole preserve of the trolleybus fleet. The Roe body was one of those timeless classics that would look good in almost any livery. I rather think that as well as those bodied by Roe, the MCW bodied Daimlers also had a window on the stairs, but if memory serves, at some stage they were all either removed or painted out.

Photograph and Copy contributed by Ronnie Hoye

20/11/14 – 11:43

Birmingham (JOJ) and Glasgow (FYS and SGD) reserved large blocks of registrations which were issued over several years. Almost all the FYS block was issued to buses and trolleybuses over the years 1949 to 1958, followed by SGD 1958 to 1964, when the year-letter phase began. Devon issued LTA registrations to Western/Southern National for buses new between 1949 and 1953.

Geoff Kerr

21/11/14 – 06:37

In Leeds while the buses were registered in blocks there was never a special series for them On the other hand all the city council ambulances were given the registration — 999!
In complete contrast West Yorkshire never used blocks of registrations even for a single batch of buses being quite content to take what the licensing office offered and if the number matched the fleet number it was very definitely good luck and not good management!

Chris Hough

21/11/14 – 10:20

Nottingham (after WW2 but not before) invariably had blocks of reg numbers that corresponded to the fleet numbers. All were in the KTV series until the big fleet of 72 Regent/Park Royals, supplied in 1953/54, took OTV 127-198, assuming the fleet numbers of Regents supplied 1934-36. Even then there was clearly some agreement with the licensing authority, since these followed on neatly from the 1949 series of Regent/Metro-Cammells KTV 97-126, which in turn took on fleet numbers previously carried by defunct 1931 Regents.

Stephen Ford

21/11/14 – 15:23

Portsmouth Corporation seemed to use whatever registrations were available in the pre-war and early post-war period. I suspect that the 1939 Leyland Cheetahs were numbered 41-46 to coincide with the allocated registrations BBK941-946. Post-war, Crossley DD42/5T No 28 was also coincidentally registered EBK 28. The others of the batch (EBK 23-27) carried numbers 11-15. The Corporation was "gap-filling" it’s number series at this stage. In the 1950’s, the Corporation had a policy of booking registrations in batches in ending 999. Thus we had 25 PD2s GTP 975-999 (58-82, 1952); 25 PD2s LRV 975-999 (83-107, 1956; 15 PD2s ORV 985-999 (108-122, 1958); 5 PD3s STP 995-999 (123-127, 1959), and 10 Tiger Cubs TTP 990-999 (16-25, 1959). After this the Corporation booked registrations that matched the fleet numbers in what was becoming the "normal fashion" across the industry from the 1960s (although I accept it wasn’t universal practice). As referred to above, it was usually ambulances or fire engines that had a "999" registration, not buses. The buses registered with a "999" didn’t go any faster than the rest, but 122 had a different and marvellous sounding exhaust note during it’s early life – certainly until c.1964/65 – very sporty! .

Michael Hampton

21/11/14 – 17:44

The West Yorkshire Road Car Company did use year block registrations in the period 1934 to 1939 and again from 1946 to 1956. An example for 1935 illustrates the method used. YG 8968 – 9015 registration marks were used for Dennis Lancet 1, Dennis Ace, Bristol G05G and Bristol J05G types. Another example used in 1952/53 were LWR 405 – 435 registration marks issued for a Bedford van, Bristol LS6G, Bristol KSW6B, Bristol KSW6G and Bristol LS5G types. Other letter groups with mixed bus types were BWT, CWT, DWU, EWY, FWX, GWX, JWU, JYG, KWU and OWX. I have omitted AWW as one mark missing in the sequence was AWW 160. After 1956 this practice of mixed bus types in registration groups ceased and shorter runs as described by Chris H were then the norm.

Richard Fieldhouse

22/11/14 – 08:58

I remember in 1967 Nottinghamshire used a block of registrations across 3 companies which as a youngster I thought unusual.
SRB 59F to SRB 65F Mansfield District Lodekkas,
SRB 66/67F Midland General REs,
SRB 68F to SRB 80F Midland General Lodekkas,
SRB 81F to SRB 90F Chesterfield Corporation Panthers.
Mansfield District and Midland General were linked so possibly you could argue it was 2 companies. Does anybody remember anything similar elsewhere?

David Hargraves

22/11/14 – 14:05

Interesting, David – especially as Chesterfield is in Derbyshire! I wonder if the Panthers were an order that was actually diverted to Chesterfield for some reason?

Stephen Ford

22/11/14 – 16:37

In 1967 wasn’t RB a Derbyshire registration? It only became Nottinghamshire later.


22/11/14 – 17:17

‘RB’ was a Derbyshire mark, and the Chesterfield Panthers naturally received Derbyshire registrations. Midland General/Notts & Derby vehicles were registered in Derbyshire up to c.1972, then Derby CBC in 1973/4 (was this after the Trent ‘takeover’?), then Nottingham LVLO.
Mansfield & District vehicles were registered in Derbyshire from 1967 to at least 1970.
Interestingly, the Chesterfield Panthers were fleet numbers 81-90, following on from Roadliners 71-80, so it may have been the Panthers which somehow dictated the above sequence.
I am sure there would have been many more instances of bus registrations following on from one fleet to another, not least because bus and coach registrations once constituted a much higher proportion of the total than they do now. Off the top of my head I recall that (c.1950) DRN241-90 were Ribble 1301-50 and DRN291-310 Preston 8-27 (all PD2s); DRN341-54 were Ribble 284-97 (Sentinels) and DRN355-67 were Scout (Royal Tigers, PD2s, and a Bedford). Don’t forget that there was ostensibly no corporate connection between Ribble and Scout in those days.

David Call

23/11/14 – 06:39

Newcastle Taxation Office allocated reversed JVK exclusively for Newcastle Corporation Transport buses and other municipal vehicles. The mark was first issued in November 1959 and remained in use until December 1963. Newcastle commenced suffix marks on 2 January, 1964.
One of the most intriguing registration features was Liverpool which issued FKF to Liverpool City Transport buses covering the D, E and G suffix.

Kevin Hey


PMT – AEC Reliance – 761 CVT – C8761

PMT - AEC Reliance - 761 CVT - C8761

Potteries Motor Traction
AEC Reliance 470
Willowbrook C41F

PMT had five of these coaches plus one similar acquisition on a Leyland Tiger Cub chassis from the takeover of Dawsons, Ash Bank. They suffered as always with AH470 engines with cylinder head gasket and wet liner seal failures. This is why this photo was taken adjacent to Llandrindod Wells Railway Station on a summer evening in June 1971. A similar Reliance had taken a party of Scouts on a weeks expedition to Tenby and inevitably the engine had failed in South Wales. I was summoned at short notice to take a replacement vehicle arriving at South Wales Transport Ravenhill Depot shortly before midnight. I chose the scenic route rather than the M6/M5 as I didn’t fancy becoming another engine failure casualty at the side of the Motorway. During 1971 and 1972 three of these Reliances were modified for one man operation and repainted in bus livery. The conversion included jack knife doors the motor for which would only fit in the space occupied by the nearside front passenger seat hence reducing the capacity to 39. As the vehicles were 13/14 years old by this time one wonders if it was really worth the effort. I recall 762 which was allocated to Biddulph Depot put in some quite respectable mileages as an omo saloon.

Photograph and Copy contributed by Ian Wild

16/11/14 – 09:44

An odd design which seems to transition from the early 1950s at the front to the late 1950s at the rear.

Phil Blinkhorn

16/11/14 – 11:21

JCN 449

Northern General had a batch of very similar C37F Willowbrook Viking coaches on an AEC Reliance 2MU3RV chassis, so as I understand it, they would have had the larger AH590 engine. Delivered in 1959, they were JCN 445 to 454, numbered 1845 to 1854. About 1967, it was decided to convert them for use as OPO vehicles, but the changes were far more radical. I don’t know if the conversion was carried out ‘in-house’ or whether they went back to Willowbrook to be done, but the whole front end was chopped off, and a new service front grafted on, I believe they were also up-seated to 41. Here is an example of the end result, I believe they remained in service until around 1975

Ronnie Hoye

16/11/14 – 18:03

Were the gasket/liner problems eventually cured by AEC?

Chris Hebbron

17/11/14 – 06:47

In a word, Chris – No! AEC’s involvement with wet liners began in 1935 with the introduction of the ‘6.6’ A172 engine (actually of 6.75 litres) in the lightweight Regal II. This engine proved to be decidedly troublesome, and the wet liner problems were carried through into its postwar ranges developed from about 1953. In the end, AEC reverted to dry liners in the AV/AH 505/691/760 engines. By contrast, Dennis employed wet liners in its ‘Big 4′ petrol and O4/O6 diesels from the mid 1930s onwards, and all were generally free of the troubles that plagued the AEC efforts.

Roger Cox

17/11/14 – 06:47

2MU3RV was still the AH470, Ronnie – 2U3RA was the AH590. Both of these had wet liners and gasket head problems. The AH691 and AH760 were new dry liner engines which did not have the same problems. Sadly the reputation was tarnished and many did not return to AEC. Also, like the later Leyland Panther, others persevered and overcame the problems.

David Oldfield

17/11/14 – 09:51

Thx, Roger. It’s amazing, from what you say, that folk continued to buy AEC’s with these engines, if they were so troublesome, although I admit that post-war distress purchasing would retain undeserved loyalty to a large extent. Were LTE’s engines of this type? I’ve never heard of problems with those Incidentally, did AEC/Leyland ever offer ‘outside’ engine options at ordering stage, such as Gardner? I’ve never heard of any, but who knows?
David O, strange that, following on with gasket/wet liner problems, which existed for decades, AEC cured Crossley’s engine breathing problem within months!

Chris Hebbron

17/11/14 – 11:37

The AV (vertical) engines never suffered to the same extent as the horizontal AH engines and substantially LTE had no problems with RMs (once the teething problems were ironed out) – including the AV590. Neither did Sheffield with its Regent Vs and Bridgemasters. [In passing, the AV version of the AH691 was actually a wet-liner and really an "out-boring" of the AV590.] It is surprising that they carried on so long before they eventually reverted to dry-liners – and as I said lost friends along the way. Those who stayed were rewarded by the AH691/760. AEC were not alone in having problems with putting an engine on its side. I am a "fan" of the O.600/O.680 – but this was not without its problems either – as Stephen Barber has alluded to in his Wallace Arnold Books. Conversely, there was enough faith in the later AEC engines to offer them, initially, as an option, in Series 2 REs and VRTs. The famous Werner Heubeck at Citybus who force BL to continue the RE for Northern Ireland was known to be very interested in an AH691 RE but BL back out at the last minute and cancelled the option – much to Heubeck’s anger. [Something similar is thought to have happened with the VRT – when someone showed interest, the option was withdrawn.] As for Gardners, there were the famous Rochdale D2RAG Regent Vs and the less famous Glasgow and Aberdeen D2RVG Regent Vs.

David Oldfield

17/11/14 – 16:50

Huddersfield JOC took delivery of 16 Regent’s and 37 Regal’s with 6LW engines between 1935 and 1939.

Eric Bawden

17/11/14 – 17:19

Forgot those, Eric. Crossley engines were another, and simpler, matter. AEC basically knew the problem – Crossley refused to pay royalties to Saurer and so mangle the design of the piston/cylinder head to make it different. AEC simply came up with a design which solved the problem without infringing the rights of Saurer. [I’m not an engineer, so I cannot elucidate.]

David Oldfield

18/11/14 – 06:23

As I have always understood it, the bored out 11.3 litre version of the AEC AV590 wet liner engine was the AV690, which was introduced at the same time in 1958. It was most commonly employed in commercial vehicle models such as the Mammoth Major V and in many export PSV’s, but was optional in the 2D version of the Regent V, and in horizontal AH690 form in the 2U and 4U larger Reliances, though it was not differentiated in the model designation.
The AV/AH691 was the 11.3 litre dry liner engine which was announced in late 1964 at the same time as its smaller equivalent the AV/AH505. The AV691 was then offered as an option in the Regent V and Renown, models, which were then designated Regent 691 (prefixed 3D) and Renown 691 (prefixed 4B) though none of the latter were built.

John Stringer

18/11/14 – 06:23

David, the wet liner 11.3 litre was the AV/AH 690. The 691 was a dry liner in vertical and horizontal formats. Even the switch to dry liners did not resolve AEC’s engine reputation. The AV/AH 505 in particular soon revealed weaknesses in service. A cover plate was fitted on the top of the block under the cylinder head, and this plate was held in place by a number of set screws. The inevitable expansion and contraction of this component in service caused the screws to fail, leaving a hole that allowed coolant to escape. This, if not spotted and remedied, could result in a seized engine. The design defects were progressively eliminated, but AEC’s reputation as an engine builder was not enhanced.

Roger Cox

18/11/14 – 06:24

Ronnie – that’s a proper bus conversion done by Northern, however as they were done in 1967 they would operate for quite a few years to get the money back. We only started conversions in 1971 and as I said, perhaps a bit late in the day – but don’t forget PMT had the largest fleet of Roadliners in the world and anything had to be tried to mitigate the chronic unreliability.

Ian Wild

18/11/14 – 06:25

Chris, for a short period in 1956/7 the AEC Regent V was offered with the option of a Gardner 5LW or 6LW engine. There were only three takers; Glasgow and Dundee Corporations bought examples with vacuum brakes and spring operated preselector gearboxes (model D2RV6G,) and Rochdale Corporation had examples with air brakes and air operated preselector or semi-automatic gearboxes, model D2RA6G. The Rochdale examples were described in my article on this site.

Don McKeown

18/11/14 – 10:19

The prototype Crossley HOE7 engine design came about when the firm’s engine designer, W.C. Worrall wwas diagnosed with tuberculosis prior to the outbreak of WW2. He was sent to Switzerland to recuperate, and, whilst there, visited the Saurer factory, where he himself had once worked. Saurer gave him permission to use the company’s advanced four valve head and toroidal piston cavity in his new engine design. Shortly after Worral’s return to Britain, war broke out, limiting Crossley’s commercial options, but three prototype engines were constructed with combustion chamber detailed design being made by Leslie Bennett, a mathematician and combustion specialist. Thus Crossley had done all the right things and succeeded in a designing a powerful and reliable unit. Then, as the new SD/DD42 chassis production began to get under way in 1944, Saurer, entirely reasonably, asked for a royalty or licence payment in recognition of the fact that the Swiss company’s patents were employed in the head design. The exact details of the fees involved have since been buried in the passage of time (probably deliberately). The Crossley MD, Arthur Hubble was having none of this, and refused to comply, instead ordering that the cylinder head of the new engine be redesigned completely to avoid any payment to Saurer. The new head had two valves per cylinder instead of four, and the toroidal piston cavity was reshaped with sharp concentric ridges, the (misplaced) theory being that these would improve the swirl effect. The new head was married up with the original block intended for the Saurer type head, and the result was a motor strangulated by hopelessly contorted airflows. In addition, poor coolant circulation led to overheating and high back pressure in the crankcase. This ill advised redesign ended the involvement of Saurer, but left Crossley with a exceptionally poor engine. When AEC took control of Crossley, it lost patience with Gorton’s refusal to attend to the cylinder head deficiencies and undertook remedial design itself. It is an overstatement to suggest that AEC simply solved the problems with the Crossley engine. The downdraught cylinder head was not a cheap conversion, and, although it did improve the airflow characteristics and reliability issues to a very great extent, the HOE7 could never be turned into a truly good motor. What baffles me somewhat is the fact that Dennis used a four valve head and toroidal piston cavity in its O4 and O6 diesels, yet no payment was ever made to Saurer. Presumably the Dennis design differed sufficiently to escape the Saurer patents.

Roger Cox

18/11/14 – 15:50

Aberdeen Corporation did have five Gardner engined AEC Regent V’s with Crossley bodies (205 – 209). In 1959 they purchased five AEC Regent V’s with AEC engines and Alexander bodies (271-275). By 1963, they also had been fitted with Gardner 6LW engines.
I seem to recall that Maidstone and District also converted some coaches in the same manner as that done by Northern General.

Stephen Bloomfield

19/11/14 – 05:57

Stephen, I think the Maidstone vehicles you refer to had Harrington bodies but the end result was quite similar.

Ian Wild


All rights to the design and layout of this website are reserved     Old Bus Photos does not set or use Cookies but Google Analytics will set four see this

Old Bus Photos from Saturday 25th April 2009 to Sunday 23rd November 2014