West Riding Automobile
1966
Daimler Roadliner
Plaxton B50F
I always thought the single deck version of the ‘Fleetline’ was called a ‘Freeline’ but it appears I was wrong, it was called a ‘Roadliner’. It as come to light whilst researching this bus that the ‘Roadliner’ was not the most reliable chassis in fact it was quite the opposite. That I find strange as the ‘Fleetline’ the double deck chassis was very reliable if you know what the problem was please leave a comment? Another interesting thing about this bus is that the body was built by Plaxton who were better known at that time for coach bodies rather than bus bodies although having looked at there website today they do four very impressive bus bodies at the moment.
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The Roadliner was a different beast to the Fleetline, it was a 36 foot long, and for it’s time, a low floor chassis, incorporating air or metalistic toggle link suspension.
In the days before one man operation of double deckers was permissible, the high seating capacity Roadliner like it’s contemporaries the AEC Swift, Leyland Panther, and Bristol RE, was after a piece of the action.
The Bristol RE proved to be the only reliable model of the bunch, enjoying large orders and long service lives. The Roadliner sadly proved to be just about the worst, due largely to it’s weird and unreliable Cummins V6-200 engine.
Later models were instead equipped with the Perkins V8 engine, but it seems the damage had already been done, with braking and suspension problems meantime manifesting themselves.
West Riding really didn’t need these problems, with their hands already full of the woes presented by their large fleet of Guy Wulfrunians.
PMT Ltd (Potteries Motor Traction Ltd) however got their hands burnt the worst as the biggest operator of Roadliners, with 62 buses and 6 coaches (?). Despite strenuous efforts to keep their Roadliners on the road, by 1970 PMT’s problems were such that they finally threw in the towel, and withdrawals started soon after. Their last left the fleet in 1976.
Keith Jackson
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You’re right about PMT’s 6 Roadliner coaches. They were fleet nos. C1097-C1099 (KVT 197-199E) and C1100-C1102 (PVT 100-102F). The first three had Plaxton bodies and the last three Duple.
All the early PMT Roadliners had Cummins engines. The Perkins alternative was trialled in the rebuilt PMT prototype S1000 (6000 EH) and then the last 10 examples (built in 1968; 130-139 (WEH 130-139G)) also had the Perkins unit.
I remember going round the PMT depots on my bike in about 1975 and seeing huge quantities of Roadliners dumped around the back of Cheadle depot prior to disposal. There weren’t any Roadliners at any other depot so I suppose this was either the last depot to operate them or it was a convenient place to collect them.
As you say, long before then the writing had been on the wall for the Roadliner and PMT tried several different alternatives; a batch of 21 Fleetline single decks in 1970 with unusual Alexander ‘W’ type bodies was followed by several batches of Bristol REs. Even these didn’t survive long, however, as the Leyland National revolution gathered pace.
Mel Harwood
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The plus points with the 9.6 litre Cummins VIM V6 200 engine were its compactness and potential to deliver a hitherto un-heard of 192 bhp (hence the 200). Tragically, the engine failed to live up to its promise, maybe because it was fundamentally a marine unit designed for totally different working cycles. Result? Mechanical mayhem.
By the time the slightly less-powerful V8 unit from Perkins was offered, the Roadliner’s reputation was irretrievably damaged. Sad, really, because in other respects, it wasn’t a bad vehicle.
Chris Hebbron
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Thank you for your comment on the Roadliner I did not know that the Cummins engine was based on a marine engine no wonder it was a disaster. When you think about it a marine engine is set at a steady rev rate and stays there for hours which couldn’t be more opposite to a bus engine.
Peter
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Early diesel locos in the UK were powered by modified versions of marine engines and seemed to do surprisingly well in general. However, there was a stage well into the lives of the High Speed Trains, when they suffered overheating problems one hot summer. The engines in a couple of power cars were strapped up with sensors and the results were a revelation to the engineers. One was that that these engines never spent much more that 10 seconds on one power setting! Your point precisely! They had to redesign the cylinder heads and radiators which cured the problem and made them more reliable and efficient. Some might argue that this survey was well-overdue! Most have been re-engined with ML (German) engines which are probably far superior to the old Ruston ones.
We know that Cummins nowadays produces some superb diesel engines, renowned for their high-revving abilities. However, I do recall that about 10 years ago, a class of diesel train here in the UK was fitted with one type of their engines and was a disaster after about three years! After mutterings about legal action, they changed all of the offending engines at great cost them themselves, better than at a cost to their reputation, I suppose!
Chris Hebbron
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Let’s not be too unkind about marine engines: after all, the Gardner 5LW & 6LW were essentially marine engines, and they had a strong claim to be the most economical, reliable and altogether unbreakable engines ever installed in a bus.
Ironic really that as the Bristol Ks and Lodekkas went to the scrapyards in the 60s & 70s, a huge proportion of their engines were shipped to the Far East to be fitted in junks, where they are probably still puttering about at that legendary 1700 rpm governed speed!
David Jones
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