Vehicle History - The Daimler Roadliner

Often cited as one of the worst bus designs to ever see the light of day in most enthusiast circles (it often shares the 'worst British bus' title with the Guy Wulfrunian), the Roadliner's story has been a source of great fascination personally for some time. This thread concerns itself with the type's origins & development history, it's service history, the issues that reared their ugly heads once in service, their rapid demise and the very few that were lucky enough to survive into preservation.

(Should say I've been meaning to get this thread out for a while now; I can thank life and my overall laziness for not getting around to it sooner lol)


(Preserved Walsall No.56 & Wolverhampton No.719 - copyright of the Federation of British Historic Vehicle Clubs)

An example belonging to Red House Motor Services of Coventry seen in Nottingham in about 1969:

Didn't Sunderland Corporation standardise on the type?

I wouldn't say it was the worst design ever, it was more a commendable concept which unfortunately didn't work in practice.

It's perhaps overlooked now that the other purpose built rear engined single deck chassis, Panther, Swift, RE, had underslung horizontal engines, the Roadliner was designed to use a vertical engine, longitudinally mounted in line with the chassis frames. The use of any of the proprietary engines available at the time simply wasn't an option because the amount of intrusion into the vehicle interior was unacceptable in terms of the space which would have been wasted. The solution chosen was to employ a Vee engine which, by virtue of it's configuration, was short and didn't intrude into the saloon by a great amount. Unfortunately the Vee engines available, firstly Cummins and later Perkins didn't lend themselves to high intensity stop-start stage carriage work. The Roadliner was perhaps a better proposition for coaching work and those that were built as coaches turned in some impressive figures regarding speed and fuel consumption. However, they too were temperamental and the Roadliner rapidly gained a reputation for being just too much trouble.

The total production of Roadliners was just over 300 but half of that number were export orders. Black and White Motorways of Cheltenham built up a sizeable fleet of Plaxton bodied coaches but none of them lasted more than seven years. Chesterfield Corporation got ten years service out of their buses, I remember them well, the sound effects they produced were wonderful!

Busaholic said:

Didn't Sunderland Corporation standardise on the type?

Click to expand...

Sunderland Corpy took a handful - they standardised on the hardly much better Leyland Panther. Biggest UK user was Potteries though Black and White took quite a number as coaches!

I remember reading somewhere about the Roadliner and how it was compromised with rushed development and the use of a Cummins engine that ran very warm and needed all manner of ventilation grills etc. It mentioned how telling it was that Darlington (home of Cummins plant) took a batch of them but cancelled a subsequent batch two years later in favour of Gardner powered single deck Fleetlines, though they did persevere and the vehicles managed about 12 years service before withdrawal (which was better than most places)

Mugby said:

The total production of Roadliners was just over 300 but half of that number were export orders. Black and White Motorways of Cheltenham built up a sizeable fleet of Plaxton bodied coaches but none of them lasted more than seven years.

Click to expand...

One of the Black & White Roadliners in National Express days (pictured below):


One of the Potteries Roadliners with grills prominent (pictured below):

If anyone has a rear end picture of Plaxton bus bodied Roadliner demonstrator KKV 800G, especially during its time in the City of Oxford fleet, I would be pleased to see it.

Mugby said:

The solution chosen was to employ a Vee engine which, by virtue of it's configuration, was short and didn't intrude into the saloon by a great amount. Unfortunately the Vee engines available, firstly Cummins and later Perkins didn't lend themselves to high intensity stop-start stage carriage work.

Click to expand...

Wasn't the Cummins engine a design intended for industrial/marine use? If so, it's not surprising that they were troublesome when deployed in a bus. As well as being a Vee the decision to use the engine was probably influenced by the fact that Jaguar had a licence agreement to build the Cummins V6 200. The Perkins V8 engine was much better and more reliable, but the damage was already done.

As well as the engines the Roadliner's suspension was I think troublesome, especially those fitted with Metalastik rubber suspension? Again I think some later examples had more conventional (Fleetline derived?) metal suspension which was less troublesome.

Of course having a Vee engine suspended right at the back of the chassis also led to issues of chassis flexing. I've heard that wooden framed bodies (such as those by Plaxton) coped better with this than steel framed bodies (Marshall?) that had metal fatigue problems.

It is interesting to speculate what would have happened had Daimler either a) progressed the initial concept for their new rear engined single deck chassis (which was initially designed to have a transverse mounted horizontal Daimler engine) or b) given more time to develop the design taken to production. Certainly the Roadliner had much to commend in theory - it was the execution and particularly the Cummins engine that were seemingly the downfall.

It may be worth a search on 'Roadliner' in the Flickr collection of Martyn Hearson, bus engineer and long term North Staffordshire resident - he tends to put quite a lot of detail with his photos. Example here:

Roger1973 said:

It may be worth a search on 'Roadliner' in the Flickr collection of Martyn Hearson, bus engineer and long term North Staffordshire resident - he tends to put quite a lot of detail with his photos. Example here:

The new Daimler Roadliner.

Another of those wonderful trade magazine full colour ads. for a refreshing new product attempting to make it's name in the market. Daimler's Roadliner was a wonderful concept built by a well respected British Manufacturer, even using the odd tried and tested component. The original idea had...

www.flickr.com

Click to expand...

He was instrumental in getting one of the few survivors (Willowbrook-bodied KRU 55F, new to Bournemouth in Sep. 1967 and fitted with the aforementioned Perkins V8 later in life) back on the road after some time off. Sounds as good as it looks (linked video from the Dave Spencer YT channel; skip to 2:30) and is a credit to him and his colleagues.