Despite all the historical trauma of Leyland, our sole remaining builder of trucks is in American ownership but still producing plenty of vehicles for the home market and for export at the factory in Leyland, Lancashire. Its major component supplier is Cummins, which is also US owned. Now in its fiftieth year in the UK, Cummins’ current engine facility in Darlington is getting into gear for a celebration this summer and looking forward to even more production, while at the same time enjoying a link with British bus and truck building that goes back five decades.
Mike Humble has been for a look around and spoken to a few informed people about their progress and experience…
Over the past few decades, the UK-based truck and bus industry has swallowed more than its fair share of bitter pills. One by one, many of the once great and mighty truck and bus names have faded away into the ranks of memory, nostalgia or simply been forgotten. What many people fail to consider is the knock-on effect to the supply chain as the vehicle manufacturers disappear into oblivion. Some component suppliers were almost as well regarded as the manufacturer whose major parts were quite often the heart of the final product.
The key component of any motor vehicle is the powerunit and, in so far as commercials and PSV chassis are concerned, the UK was once home to some engine makers of global repute. Great names such as Gardner and Rolls-Royce powered many vehicles from the stables of AEC, ERF, Foden and Scammell – all of the aforementioned have either been lost through acquisition or through the decline of our manufacturing industry over recent decades. Those engine builders who still have a UK presence such as Perkins and CAT have since retrenched from automotive applications to concentrate solely on the less glamorous construction or power generation sectors.
The good news is we still have a major truck builder (DAF) and a collection of bus manufacturers in Britain along with their supplier of engines. American-owned Cummins have enjoyed a solid UK presence since 1956 when the company opened its first engine plant in Shotts, Lanarkshire to service a nearby construction equipment plant with powerunits and other engines for various rail-based projects. To this day, Cummins UK still remains heavily involved with rail and locomotive power through its Daventry facility – if you ever wondered where that thrum and power comes from when travelling in a Virgin Voyager train… You have Cummins to thank for that!
The Higgs and Hill-constructed Darlington facility came online in 1965 through a joint venture with Chrysler and this year celebrates its 50th Anniversary of engine production in a town that is synonymous with engineering excellence. Cummins’ first foray into the bus market came with its V6 engine being fitted to a Daimler chassis. In fact, Darlington Corporation Transport – barely a mile from the factory – bought a batch of twelve Roadliner buses in 1967. Its earliest automotive products were no match for the likes of Gardner or Rolls-Royce for reliability or reputation, but it listened to operators and engineers views and concerns very carefully. Cummins went on to dissolve the Chrysler tie-in and tackled its early reliability issues head on with development engineers on both sides of the Atlantic turning the fortunes round to where they are today – the world’s largest and most respected, independently owned engine manufacturer.
But it hasn’t all been sweetness and light over the years at Darlington. The slump in vehicle sales around 1980 caused by a general recession forced Cummins to scale back production and cut costs. The component plant, operating next door to the assembly lines, provided parts, castings and other raw components was sadly closed down as was the production site at Shotts in Scotland and the threat of total shut-down was imminent. During this difficult period workers, plant managers, Darlington townsfolk and local politicians rallied round to make their case to the Cummins hierarchy. Without a new product in the pipeline or a huge upturn in business, Darlington seemed doomed.
Cummins switch to Plan B
The plant produced components and V engines for export but when this ceased there was little to keep Darlington viable hence the total shut down plan – but the plant pulled through. In 1986, with an upgrade which cost of over £13.5 million, Cummins re-fitted the Darlington plant for production of the all new multi-purpose B Series engine in both 3.9 and 5.9-litre capacities. The larger 5.9 litre unit became the sole power unit for the revised Leyland Roadrunner – the engines first major recipient, with rival manufacturers such as Dennis, ERF and Foden eventually taking the B Series unit for their bus and truck ranges after the engine very quickly gained a superb reputation for economy, reliability and ease of servicing. This engine is still in production, albeit in a non-automotive format, to this day and has become the world’s most produced light commercial diesel power unit since its initial launch.
Leyland was starting a process of running down its own engine production and realised that, to make a global success with its vehicles, it needed to out source its power units. The well-received Roadrunner of 1984 may have looked new inside and out, but the engine was an ageing design called the 6.98 series. Despite a recent improvement programme, the 6.98 was at the end of its design scope. Leyland had decided they were to design and build no more new designs for future requirements and, besides, their reputation for engines was only, at best, tolerable. Cummins had been supplying Leyland with heavy truck engines for some years, but a new venture was being put together to bring a whole new dimension to customer/supplier collaboration.
An engineering alliance team between Columbus USA, Darlington and Leyland was formed to develop the Cummins B Series unit into a perfectly-honed installation for its first UK recipient – the Roadrunner. Some strict design criteria ensured that items such as the alternator compressor, fuel pump, manifolding and ancillary components were fitted in ideal places to match the chassis of the truck and contribute towards reduced downtime. This was more than just a bought-in engine, it was a fully-developed package tailor-made for the Roadrunner that had more testing and development work bestowed upon it than any other truck engine at that time. Cummins’ own testing alone amounted to some 170.000 hours and nearly 12.5 million miles. The Cummins – Leyland alliance was hugely successful and continues this day with DAF.
Engines which were produced to Leyland Trucks’ specification were submitted to three phases of further testing that included 1500 hours running at full power with periods of shut down, 2500 hours at rated engine torque and a gruelling 3500 hours of 5 per cent overfuel and 10 per cent over-speed over a cycle of maximum speed, idling, maximum speed and shutdown. Development drivers also tested a prototype chassis by downshifting the gearbox almost 10,000 times to simulate a 50 per cent over-speed of almost 4200rpm, the Cummins B Series even shrugged this manoeuvre off. Key to this new engine’s inherent strength were massive bearing surfaces, a rigid cylinder block, effective cylinder head clamping and state-of-the art production facilities with all parties being focussed on a right first time approach to engine building. At the point of launch, this all-new design was by far the most tested and proven diesel engine in the world.
6 Cylinders 5.9 litres… two wheels!
Needless to say, the B Series became an instant hit with drivers, operators, fitters and the motoring press who applauded its modernity, its frugality, its reliability and low cost of ownership. And yet the B Series was an seemingly unexotic design brief that featured a simple bored block construction rather than using cylinder liners and it was not even originally designed to be reconditioned when a unit finally became life-expired. The engine not only breathed new life into existing truck designs, it soon became a popular choice of which to re-power older vehicles. Bedford buses and coaches were still popular with low-cost operators and a fully-backed conversion called Bedford Re-Power found the Cummins B Series even more customers.
“I couldn’t believe just how car-like the little Roadrunner felt with its pin sharp, rock steady handling and instant performance” – Stunt and Precision driver Russell Swift on his Cummins-powered Roadrunner experience
It seems no matter who you speak to about the B Series, irrespective of their experience or exposure, the engine comes in for high praise. Even the odd celebrity has had some kind of experience with the engine. Many of you will have heard of Russell Swift – the well-known stunt driver who became a household name thanks to the famous Austin Montego TV advert. Russ had done a similar twowheel driving publicity stunt for the newly formed AWD Trucks business but not without incredible stress. He told me; “The handling and performance of the AWD TL was so worrying and unpredictable that the whole experience actually gave me an ulcer with stress trying to get the trick right… which I did but I vowed never to do it again in a truck.”
So when Ever-Ready contacted him to do some publicity stunt work in a Leyland Roadrunner, he rather swiftly (no pun intended) declined the offer. However, they were persistent and Russ eventually agreed to test drive the truck before committing fully. Russell told me recently: “I couldn’t believe just how car-like the little Roadrunner felt with its pin sharp, rock steady handling and instant performance, it was in a different league to my last lorry experience and the job went without a hitch… a lovely truck and engine” – the latter being a good testament for the Darlington built 5.9 litre Cummins B. Just like the engine in the truck in question and, indeed, myself, Russ is a Darlingtonian born and bred. When I asked him if he knew the engines’ locality, he smiled, shrugged and quipped; “well there you go you see” – nice one Russ!
I recently visited the Darlington plant to witness the current Euro 6 range of engines being produced – my first time there since 1987 as a schoolboy. For someone like me who fully understands modern technology in an engine, I still walked away breathless with admiration at the rapid advance of quality and technology for the diesel engine. It was not that long ago that a diesel engine didn’t even require an electric current to run, yet they now harness more technology and development than your average petrol car and it’s us Brits who lead the field in diesel engine emission technology – I’m quite proud of that. But Darlington also plays a massive role in green engines, its home to Cummins Emissions Solutions who develop, test and manufacture a range of emission filtration / after-treatment and exhaust catalyst systems in a very clean laboratory type environment.
Over 1.5 million engines have been produced so far and well over 100.000 emission systems on top of that, which is an impressive figure. Its latest engines are just as popular world-wide. Yet Darlington still produces the B Series along with the 8.3 litre C Series units in diesel and gas format for marine and power generation purposes only. The present range of engines for automotive use are the four and six cylinder 4.5/6.7 litre ISB and 8.9 litre ISL engines with the first two letters standing for Interact System which is Cummins’ patented electronic fuelling and telematics control programme. The bulk of Darlington’s output is destined for automotive-based applications, others are destined for power generation, plant and marine use.
Despite what pundits may have you believe, we are producing more cars, vans, trucks and engines in the UK than we have done in long while. Cummins, quite rightly, recognise that Darlington is a centre of excellence within engine manufacturing thanks not only to the quality of the engines but the key attribute of the finished product – the staff who work there. The Yarm Road premises, which are situated on the extreme east side of the town that’s steeped in engineering history, currently employ over 600 people involved with the manufacture of engines to over 2000 differing customer specifications.
There is a nice relaxed atmosphere as you meander amongst the men and machines inside the factory and the feeling of camaraderie in the huge works canteen during the lunch break was more than obvious. But what did impress me the most was the attention to detail and cleanliness everywhere you look, I had a good look at a finished unit awaiting its next move to the paint booth. Not a single burr or ragged edged casting could be spotted and the factory is very highly mechanised, too. But it takes a human touch to have that all important eye for quality… and it’s certainly noticeable, too.
The Bus Operator Experience
But how do the Darlington built-engines perform out in the field and, more importantly, a few miles down the road? I took time out to visit a good friend and customer of mine Austin Blackburn, owner of Go-Coach Hire in Sevenoaks, to ask his frank and honest opinion. As friendly as they come but brutally honest as they go, Austin is a big fan of Cummins engines with the bulk of his service bus fleet being powered by Cummins units from the four cylinder iSB up to the legendary L10 unit. Even his brace of heritage AEC Routemasters have been re-powered with a turbocharged B and a de-rated 8.3 litre C Series.
“They’ve been invaluable and I can probably say that we couldn’t and possibly, dare I say, wouldn’t have built the business to the effect that we have today without hard-grafting buses with dependable power units” – Go-Coach Hire Owner and Mechanic Austin Blackburn on the importance of a good engine
Owner Austin was keen to point out how dependable and reliable a Cummins engine is: “I’ve been working on these engines since 1988 and have found the B Series, especially in Euro 2 format, unbeatable. The back up is best in the business and they tend to be bulletproof. In good order, they run smoothly, efficiently and just seemingly run forever… they just get on with the job.” I asked him whether they had been that much of an asset to his business. “Most certainly.” He expands with: “They’ve been invaluable and I can probably say that we couldn’t and possibly, dare I say, wouldn’t have built the business to the effect that we have today without hard grafting buses with dependable power units.”
Not only does he run a bus and coach operation, Austin is also a time served fitter who did his apprenticeship with London Transport. His other company, The Bus Doctor, specialises in third party maintenance and repairs for PSV and light commercials. They have extensive experience with current Cummins engines, too. Austin was keen to point out that even though the current Euro 6 criteria has given many engine builders and operators something of a headache. He stated: “I doubt any other manufacturer has invested so much time and money into engine emissions” – he could be right.
Calling on many years of experience, Cummins have certainly helped the UK bus industry succeed to the point where they have today. The Transport De-regulation Act which came into effect in 1986 caused a great deal of heartache and uncertainty for operators and chassis builders. But it opened up the marketplace towards smaller buses rather than lumbering double deckers and Dennis were keen to exploit the new trend of Midi-buses. Subsequent models such as the Dart and Enviro 2/3/400 range all rely on Darlington built Cummins power units, Optare and Wrightbus soon developed their own range of smaller mini and midi-buses mostly powered by Darlington built engines. Even the Borris-Bus hybrid is Cummins powered.
Bringing it all back home – can you help?
As with many other global companies, Cummins have plants overseas to supply local markets or to make a product cost efficient. The current Euro 6 four cylinder ISB engine is produced in China but all that is to change in the not-too-distant future. In the quest of better lead times mainly to cater for the thriving local UK bus manufacturing industry, Cummins have decided to bring production of this unit into to Darlington which takes effect as of later this year. The news is a great morale booster and testimony to how well regarded the County Durham facility is both within the company itself and is reckoned to boost annual production to the tune of an extra 1000 units annually.
Worthy of celebration indeed but Cummins also have that covered – to commemorate 50 years of the factory, the company is holding an event on 11 July at the Darlington site. They are keen to source the oldest Cummins-powered vehicles still on the road to join their display of vehicles. If you own or know anyone who runs a heritage Cummins-powered bus or truck who may like to join in the event, contact Steve Nendick on 01325 556717 or send an email to: firstname.lastname@example.org for further information.
To conclude, it’s fair to say that Cummins in the UK has an illustrious past, a respected present and a bright future in engine manufacturing – and long may it continue.
Happy 50th Cummins Darlington!
[Editor’s Note: Thanks are due to Mike Brown, Tim Hamilton and the good folk at the Darlington plant for their great hospitality on the day. Also to Russell Swift and Austin Blackburn for the thoughts and experiences they have shared.]
Moving on to Rover and then PSV / HGV, he has circumnavigated most departments of dealerships including parts, service and latterly - the showroom. Mike has owned all sorts of rubbish from Lada to Leyland and also holds both Heavy Goods & Public Service Vehicle licences, he buys & sells buses and coaches during the week. Mike runs his own automotive web site and writes for a number of motoring or commercial vehicle themed publications
Latest posts by Mike Humble (see all)
- Events : Cummins Centenary Party – display vehicles invited - 14 July 2019
- News : Redundancies announced at SMTC UK in Longbridge - 11 May 2019
- Events : Preview – Practical Classics Restoration Show 2019 - 18 March 2019