Bristol RE

Bristol RE

As a graduate engineer I found myself training at the Brislington works of Bristol (Commercial Vehicles Ltd) when the RE was about to be constructed - in fact I was on the production line when the first production model was assembled - I took in my Bus and Coach magazine with an exploded sketch of the layout to help us put it together! As an aside, the same vehicle eventually became an experimental vehicle and I had the pleasure of driving the only RELH6B - a turbocharged horizontal version of the Bristol BVW engine!
It is interesting that Bristol did not extend the MW, like AEC and Leyland extended their Reliance and Leopard models to meet the new 36 ft maximum permitted length. Cyril Eyles was the down to earth engineer who dreamed up the layout of the RE I believe. The glories were that the engine came closer to the back axle than the Panther and Swift et al and drove forward with a smaller diameter higher speed prop shaft over the dropped centre rear axle into the gearbox - originally the synchromesh box designed specifically from scratch with input and output flanges at the same (back) side. The drive from the gearbox went straight into the standard Lodekka rear axle - a well proven unit at the time (and only came to grief on the VRLH6L coach version with the Leyland 680 Power Plus engine). This provided a better, even optimal, weight distribution between axles to provide better ride, steering and braking performance.
Clutch life became an early problem related to drivers not able to hear the engine and the higher torque of the 6HLX engine. Later calculations proved it to be of too small a diameter. We discovered that Leyland and AEC were having similar problems with 36ft long vehicles. While various modifications were tried, the change to semi-automatic using the SCG epicyclic box with BCV transfer gear to bring the output to the rear was put in hand.
The earliest vehicles had a rear suspension with rigid beams pivoted at the front each with two air bags, one in front and one behind the rear axle. This beam failed in service and the experimental department confirmed the mode of failure on a 24hr running test rig. The decision was taken fairly swiftly to replace this arrangement with something that had worked well - the Flat Floor Lodekka (FS - FLF) arrangement of 'flexible beams' with single airbags behind the rear axle. It was my job to produce the Service Modification drawing to campaign change the rear suspension!
With regard to the engines - I was with Eastern Counties as a junior engineer when the incoming General Manager wanted to be seen to have fast coaches, so he had one vehicle (ECOC RE890?) converted to horizontal Leyland 680. BCV also introduced it as an option and certainly Crosville went for it because there REs were being overtaken by Ribble Leylands on the M1. However they soon found that if two REs one with Gardner and one with Leyland engines left London at the same time, the Gardner was home first.
When I was at Ribble, I eventually got Leyland to admit that the reason that the longer Leopards faded on Motorway hills, whereas the double deck VRL also with a 680 engine could go '70MPH uphill', was the unwillingness of Leyland to produce a 'Power Plus' version of the horizontal engine because the exhaust manifolds would get in the way of the chassis frame. Signs of Leyland's fall from excellence!

Geoff Pullin
12/2014


21/12/14 - 10:59

I seem to remember during the sixties Buses Illustrated ran a "joke" article called "Ready, steady, bus", which tried to bring our hobby up to date with a bus news bulletin presented in the style of contemporary pop music programmes. It referred to "Bristol's new smash hit, 'MWL'"
At the time I wondered if that was just a figment of the writer's imagination, or had Bristol offered the MW in 36ft length, but not sold any. This article answers the question! I think the Lodekka was actually offered as a chassis to be bodied by non-standard builders in it's final years after the partial takeover by Leyland, but again none were sold.

Don McKeown


22/12/14 - 07:36

I have looked through the linked article related to the exchange of VRT for FLF between SBG and NBC.
It suggests that it was the Tilling operators who wanted the transverse engine layout. I think you will find that the change of engine position was brought about by legislation that provided grants to bus operators for introducing vehicles suitable for one man [sic] operation and I understood that the small print stated transverse rear engine for double decks. I would appreciate any 'inside' information on the reason for the rapid design change from the reasonably well developed longitudinal engined VRL to the VRT.

Geoff Pullin


22/12/14 - 12:08

From the point if view of drivers and passengers alike I always found the RE to be the very best of the first generation rear engined single deckers. For the driver it was well behaved, smooth and free of any nasty vices. The virtually universal, but not exclusively so, smart looking ECW body was simple and uncluttered within and the model was the outright winner in its class for me. As a luxury coach the RE was equally delightful and well behaved. Having driven and ridden in many other brutes of the period, of famous makes, I feel free of any guilt in this enthusiasm.

Chris Youhill


23/12/14 - 05:20

A couple of observations. Firstly, the arrangement of the RE engine and gearbox was apparently selected because BCV wanted to offer a short version, and the Gardner engines were relatively long, so that the rear overhang would have been too long if the gearbox was between the engine and the rear axle.
Regarding the change from the VRL design to the VRT, I suspect that there is some truth in both of the reasons given. The early bus grant specs did only refer to transverse engined double deckers (allegedly, the specs were drawn up by people from Leyland). However, there was another issue - or, in effect, the same issue as that which prompted the arrangement of the mechanical components of the RE. With the engine mounted longitudinally, and the gearbox, the rear overhang was so long that the total vehicle length could not have been less than about 32'7". At that time the Construction and Use regulations specified the proportion of the length that could be outside the wheelbase. Positioning the gearbox ahead of the rear axle in the manner of the RE would not have been possible with a double decker. Thus the vehicles would have been large enough to have about 80 seats, but at that time they would principally have been used to replace early LDs, none of which seated more than 60. Everything else aside, the extra fuel used would have done nothing for the Tilling Group's operating costs per mile, and, it is known that General Managers were "incentivised" to try to reduce operating pcm each year, even if only by a fraction of a penny. So it is perhaps understandable that Tilling managers wanted a shorter model. In practice, very few 33' double deckers were delivered to THC/BET/SBG/NBC companies.
There is another aspect to the story that is also rather curious. BCV wanted to return to a single type of "universal" chassis, harking back to the days of the K and L types, and the VRL would theoretically have achieved this. Production economies would have been the benefit. So it seems rather strange that, when BCV offered the VRL as a single decker, the prices quoted were higher than for an equivalent RE.

Nigel Frampton


07/01/15 - 06:36

What a fascinating article Geoff. I'm quite envious of you training with Bristol Commercial Vehicles, and on the early REs too, at what must have been an exciting time in the industry. The RELH with the turbocharged horizontal Bristol BVW (BHW) engine you mention was actually the third of three prototypes built -this one being chassis number REX.003. After several years serving as a BCV testbed vehicle, it was eventually kitted out by ECW to full coach specification (C47F), and entered service with West Yorkshire as its CRG1 (OWT241E) with Gardner 6HLX engine in 1967. It has always been my favourite RELH coach, and was the only one of WY's CRGs to have a manual gearbox. Conversely, WY's earlier 'express' RELH6Gs (ERG1-11) all had manual 'boxes apart from ERG7, which was converted to semi-automatic transmission. From new in 1966, this coach was dogged by an annoying vibration at speed. Various remedies were tried - new flywheel, gearbox, rear axle - but to no avail. In the end someone suggested fitting a fluid transmission, and the vibration magically vanished. Presumably something must have been misaligned somewhere in the original configuration, but the new fluid flywheel and epicyclic gearbox did the trick.
West Yorkshire did have some problems with the manual gearbox RELLs, relating to the synchromesh balk rings failing from time to time. Despite encouragement from Bristol for drivers to use the synchromesh as intended and depress the clutch once for each gearchange, most drivers appeared happier using the tried and tested method of double declutching to effect better changes. This could be confirmed by the "FRRRP! FRRRP!" hiss of air emanating from the air assisted clutch - one "FRRRP!" for each depression of the clutch pedal.
Nigel's comments relating to the Bristol VRL also ring true. The New Bus Grant double-decker specifications at the time did indeed only refer to transverse rear-engined models, and Leyland was involved in advising on this. A shorter VRL would have fallen foul of the Construction & Use Regulations as Nigel states, due to the rear overhang of a vehicle being determined as a proportion of the wheelbase. Therefore, the shorter the wheelbase, the shorter the rear overhang had to be to reduce disproportionate outswing at the rear. Some years later, this caused similar problems for Leyland, when designing the short National. The long wheelbase National had a long rear overhang due to the engine and gearbox being mounted behind the rear axle. The short wheelbase model had shorter window pans due to the body pillars being closer together. This spacing, together with alterations to the fan drive, allowed the rear overhang to be reduced and conform to C&U regulations. The engine compartment was more cramped on the SWB Nationals as a result, which made some engine maintenance tasks more difficult.
Now, going back to CRG1, just before Christmas I finally took delivery of a model of my beloved coach (by EFE) after waiting around 47 years for the privilege! It is a fine and beautiful model however, and has been well worth the wait.

Brendan Smith


13/01/15 - 11:41

The first 250 or so RE buses (not coaches) for Bristol Omnibus all had Leyland engines. Gardners began to come in during the 1972 delivery but there were only 14 Gardner-engined REs in all out of nearly 400 (including RESL). For coaches and DPs, the split was more even but Leylands still predominated.
I worked in the Traffic Department 1970-3 but the talk was that Gardner's could not meet Bristol's demand for large numbers of REs so a decision was made to standardise on Leyland engines. I also heard that the few Gardners were diverted from another NBC order. Someone may know more!

Geoff Kerr


21/10/15 - 07:09

With regard to Nigel's final paragraph, when I was training at BCV (1962-5), the VR was only known as the 'N' type and the SU was the 'P' type - the latter only a glimmer in Cyril Eyles' (CE) eye - and always referred to as likely to have a Perkins engine.
With regard to Geoff Kerr's comments about BOC RE buses - I think you will find that the decision to go to single deck city buses was taken by a General Manager, hot from Ribble (where similar decision had been taken - also using REs!) The fairly new CE at BOC at the time (Philip Robinson) I think you will find started life as a Leyland senior apprentice and may well have had biassed views on engine provider. Even within NBC, personalities could be decisive! At Ribble, of course, Harry Tennant decided (in BET days!) the RELL6L drank too much fuel and specified Gardner for the second batch although shortage in NBC early days meant he had to accept RESL6L thereafter.

Geoff Pullin


22/10/15 - 07:21

The Gardner-engined REs that BOC received in 1972 were indeed diverted from another operator - Western National. There were also 3 Plaxton-bodied RELH coaches, diverted from the same source. I understand that WN had financial difficulties at the time.
I am slightly intrigued by Geoff Pullin's reference to the SU as being known as the 'P' type. Duncan Roberts, in his book on the RE, mentions a proposed 'P' type, that would have been a lightweight rear-engined single decker (which, of course, never materialised). We can only speculate on what it would have been like. I had never heard of the SU being referred to by any other designation, and by 1962 it would have been in production for a year or two, so the use of an alternative designation seems a little odd.

Nigel Frampton


22/10/15 - 10:55

Perhaps time is playing tricks as indeed the SU was in production by 1962. Perhaps the P type was a successor for it - the Albion engine was not over popular then. I can't remember it having a rear engine when I drew out a draft specification leaflet for the proposed new models that Chief Engineer Cyril Eyles intended. A quick flash of wisdom now tells me that the P type of course became the LH which did indeed have a Perkins engine and I think the Leyland engine was an option that nearly everyone took!

Geoff Pullin

 


 

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