Daimler Roadliner SRC6 - MTT Perth style

[Herbert]

Although used briefly on a Hino Rainbow during the late 1980s, to WA enthusiasts No 10 is synonymous with Perth's sole Daimler Roadliner.

The body on No 10 was commenced by the MTT and finished by Boltons, and entered service in September 1967, stationed at Perth's Daimler mecca, Trigg Depot. It was the first bus to feature a wide centre exit door (if we momentarily ignore the Sunbeam trolleybuses that only had a single wide centre door!) that was to be a standard feature of Perth buses until 1980.

10 on an enthusiasts' extravaganza:
<img src="http://perthbus.info/DUNNO/10A.JPG" width=600>
<img src="http://perthbus.info/DUNNO/10B.JPG" width=600>

In November 1973, 10 was transferred to Causeway Depot as a yellow City Clipper, duties it remained on for the remainder of its PSV life. Often after school I'd enjoy a ride on 10 before going home. With its Cummins VIM200 V6 diesel and a very melodious Wilson gearbox, what a thrill!

Dennis96 pics of 10 as a yellow City Clipper, taken in 1974. The first photo was posed to illustrate 10's uniqueness as the only MTT bus with dual headlights.
<img src="http://perthbus.info/TNP/10C.JPG" width=600>
<img src="http://perthbus.info/TNP/10D.JPG" width=600>

In late October 1979 10 was withdrawn for conversion to a mobile information office, and was sold for use as a mobile home in January 1984. Recently by pure fluke I stumbled across this photo on the internet. The tropical roof (fitted when it became the info office) and the dual headlights gave the bus's identity away!
<img src="http://perthbus.info/DUNNO/10E.JPG" width=600>

Over the years I've come to like Adelaide's lantern-front buses, but I just can't help thinking Perth's Roadliner was a very smart vehicle indeed.

[Busman]

Did it still have its superb badge fitted?

In your thread on Adelaide's Roadliners, I mentioned the badges visible in the shots.

202-235 had badges like those photographed, but 201 had that large one like the one in these shots, only instead of the black background, it was red.

It was fitted above the large windows on the front, right under the destos and looked absolutely impressively superb!

Some years ago (about 15), it was displayed inside the National Railway Museum at Port Dock but hasn't been there for some years. I don't know where it is now but hopefully at least up on someones shed wall and not ditched out.

[Dennis96]

The "tropical roof" on No 10 when it was a mobile information office was originally on Leyland Panther 960 as a trial to reduce interior temperatures during summer. It was unpainted metal - either stainless steel or aluminium.

[Swift]

I notice it's stance is very much like an AEC 691 and 760 Swift(the 505 Swift is a different chassis).
It's wheels look very AEC like as well.
I could swear that the Roadliner was designed to compete with the Swift/Leyland Panther.

[Dennis96]

Wheels were an item bought in from outside suppliers, so it is possible the same wheels were used on the Daimler Roadliner chassis as on the AEC Swift/Leyland Panther.

The Roadliner was often used as a coach chassis in the UK and was relatively rare.

[Herbert]

Here's some figures on Daimler Roadliners for those (like me) who are statistically minded:

Only 351 Roadliners were built. Most had Cummins V6 engines, the exceptions being:
2 prototypes chassis with Daimler engines;
1 prototype and 27 chassis for Pretoria with Leyland engines;
33 with Perkins V8 engines;
18 for Belfast with Gardner engines.

Adelaide's fleet of Roadliners was the third largest in the world. Potteries UK had the largest with 59, second being Black & White with 38.

That the type wasn't successful may be gauged by the fact that Potteries cancelled their order for a further 9; Johannesburg took delivery of 10 but cancelled the next 10; likewise Darlington UK took delivery of 12 but cancelled 12.

[Swift]

What sort of suspension did the roadliners have?
The 691 and 760 Swift have leafs in the front and coil springs(poor man's airbags IMHO)in the rear .
A little off topic but did any AEC Swifts have air suspension as an option?
I do know that the AEC Reliance had them as an option in the UK at least and the Leyland Panthers (which have the same chassis as the AEC Swift 691/760)in Brisvegas were airbag equipped which is very impressive for a type that was introduced there in 1968 or before.

[Busman]

A little off topic but did any AEC Swifts have air suspension as an option?.

None of Adelaide's had it fitted that I'm aware....but a Regal VI had it in 1963!

[RK215]

What sort of suspension did the roadliners have?

The Roadliner had air suspension as standard equipment, to some extent deriving from Guy’s extensive experience with the Victory UF. There were 2 air bags per axle. The front axle was located by trailing links, the rear by an A-frame and a Panhard rod. It actually looked quite neat as seen in diagrams and photographs. It’s a pity that the chassis was let-down by a poor choice of engine – in retrospect, a short-stroke, 90 degree, three-throw V-6 doesn’t sound too bright a combination. Daimler might have done better to have skipped this innovation, instead fitting the Gardner 6HLX longitudinally, which would have given the Roadliner immediate market appeal. Even the higher cost of adapting the 6HLX to suit the 1962 prototype horizontal transverse engine installation might have paid out in sales terms. (A horizontally-opposed flat 6 might have been a better idea for this kind of chassis, but I don’t suppose that Gardner would have had anything to do with that idea. Maybe Meadows would have done it, though.)

At a later date, Metalastik rubber suspension was introduced as an option. Evidently this was similar to the system long-used by British operator/builder Midland Red. At least some of the UK PMT fleet had rubbers.

The Daimler Roadliner was also offered as the Guy Conquest in some markets, although I don’t know if any so-badged were actually sold. Conversely, a few Guy Victory UF models were badged as the Daimler CVU6LX. Now there’s a thought for unfussed power – a long wheelbase Guy Victory UF with a Gardner 8HLXB and say a 5-speed epicyclic. (Actually, I’m not sure that there was ever an “H” version of the 8LXB, but it should have been possible. But if not, the horizontal version of the Rolls Royce C8 might have been an alternative, and perhaps quieter as well.)

Cheers,

[RK215]

A little off topic but did any AEC Swifts have air suspension as an option?
I do know that the AEC Reliance had them as an option in the UK at least and the Leyland Panthers (which have the same chassis as the AEC Swift 691/760)in Brisvegas were airbag equipped which is very impressive for a type that was introduced there in 1968 or before.

AEC did offer the option of air suspension on the Swift when it was announced circa September 1964. Whether any were built with air suspension, I don’t know.

The early Swift literature shows the layout for the high-frame, coach version (of which few or none were built). It is essentially the same as that for the Regal and Reliance, with 4 air bags per axle, and trailing links and Panhard rods for axle location. The low-frame, bus version is not illustrated, but is described as having the same arrangement as the coach for the rear axle, but with an air-leaf arrangement for the front axle.

Given that the low-frame Swift had the basically same front end as the corresponding Panther, one may reasonably assume that the air suspension option was very similar. Unfortunately, the available Panther literature doesn’t help very much, as the air suspension option is illustrated for the high-frame coach version only. It follows Worldmaster/Leopard practice, with 4 air bags per axle mounted on drop beams, and single blade locators.

The Panther bus front end was derived directly from that of the Atlantean, for which an air-leaf front suspension option was offered during 1960. Again, I have been unable to find any diagrams or photographs of the arrangement. On the other hand, the air-leaf front suspension option for the Lion PSR1 was well publicized. This has low-rate leaf springs mounted under the chassis, with air bags (one each side) between the spring centres and the chassis. I infer that the Atlantean/Panther/Swift arrangement was similar, although with the leaf springs mounted outside of the chassis rails, there would have been outboard cantilever brackets which loaded the air bags.

Perhaps someone familiar with the Brisbane or Perth Panthers can confirm or deny?

Circa 1966, AEC also offered a coil spring option, at least for the Reliance, and some were built as such. I understand that it used the air suspension basic layout, but with coil springs replacing the air bags. Reliance 691 models so-equipped carried the 8U model number, the same as the air-suspension version. The standard, leaf-spring model was the 6U.

I suspect that the Adelaide Swifts followed the Reliance coil spring pattern for their rear axles. It’s interesting that a leaf-coil arrangement was not used for the front axle – maybe the benefits didn’t justify the extra complexity.

Swift early history appears to be a bit convoluted. Initially, AEC announced the Swift 505 in the 36 ft length (18’6” wheelbase) and in low-frame bus and high-frame coach variants. Alongside it, and essentially for export was the Merlin, similarly dimensioned, using the high frame, and (it is assumed) with Regal VI running units.

The coach version faded away, and the Merlin metamorphosed into the Swift 691 bus chassis, although LT retained the Merlin name. In 1966 or thereabouts, AEC added a short, 33 ft version (16’6”) version of the Swift 505, using the Panther Cub frame, albeit with rear-end changes. As far as I can work out, Adelaide had the largest fleet of big-engined (36 ft) Swifts outside of LT, and Canberra had the largest fleet of 33 ft Swift 505’s outside of LT. (I don’t know who had the largest fleet of 36 ft Swift 505’s, though.) It’s more evidence that the Panther/Swift story is very much an Australian story.

Cheers,

[Swift]

That was very interesting information.It's good to see somebody still has it.
Can you explain how the 760 Swift chassis came about.It was the last AEC offered on the Australian Market .Around 60 entered service with the gov't buses in Adelaide in 79 (the year of AEC's closure)and the rest went to various private operators. I am not aware of any other country that ran them,England included.
I have heard they were diverted from Durban ,South Africa but that is all I know to date.Any details of how that model came about would be appreciated.

[tbc1983_]

Herbert, absolutely good pics!!

I love the detail on the front of former UQB.010, absolutely stunning!!!
2 questions, how come pre-O.405NH days, MTT/TP buses didn't have dual headlights?
Cost?
No need?

And why did MTT have only 1 Daimler Roadliner? (Apologies if this has been explained before).

I miss full-width middle doors...

Cheers!

[Herbert]

This was the only Daimler the MTT purchased themselves (all the rest were acquired from private companies & the WA Govt Tramways). Very soon, I'm sure the MTT was glad they only had one: the Roadliner was definitely a "blunderbus".

I have no idea about the headlights except that perhaps modern sealed-beam headlights were considered adequate. No 10 was one of the last buses to be delivered with "side lights" (ie the cute little clearance lights at the front below the beading).

[Guy_Arab]

Perth still can see one Daimler Fleetline driving round Perth. Friday it was seen driving between Victoria Park and Perry Lakes.
It was quite nice to drive gets alot of attention from people in the street.
The Guy Arab MAN at the wheel

[Swift]

No one has explained why it is a blunderbus.
The only thing I have been told is that Cummins were primarily specialists in truck engines and the output was too much strain on the drive line.
I can't get over how similar it's stance is to the AEC Swift.

[RK215]

The choice of engine was the main reason for its being a “blunderbus”.

In the 1960s, Cummins had a good reputation in terms of durability and reliability for its heavy-duty in-line 6-cylinder engines (of 12 and 14 litres displacement) in the NH, NT, etc., series. Perhaps they were not quite as good as the British engines in terms of fuel consumption, but they offered the possibility of somewhat higher power outputs, and so became popular in export model trucks by the end of that decade. The only comparable British engine of the period was the Rolls Royce C-series, and that never achieved the same widespread use that the Cummins did.

But the 1960s was also a time for “experimentation”; one direction explored by several engine builders was the short-stroke vee-form engine with relatively high rotational speed. Cummins developed both small and large vee-engines, each in 6- and 8-cylinder forms. In particular, the smaller engines were used in the Dodge K500 series tilt cab trucks, albeit under the Chrysler brand. And the small V8 was an option in the Ford D1000-series truck. The larger Cummins vee-engines seem to have had fewer applications, the Daimler Roadliner being notable. By all accounts both the small and large Cummins vee engines did not compare well with the big in-line engines in terms of durability, reliability or fuel consumption, and they seemed to be quite noisy, with a “note” that may have been obnoxious to those accustomed to the AEC, Leyland and Gardner in-line sixes.

Given the conservative nature of British operators, the Roadliner presented an engine concept that in and of itself was “alien”, and liable to meet with resistance simply on that count. Couple this with the poor execution delivered by the Cummins V6, and the “nail was in the coffin”. Apparently British operator Potteries Motor Traction went from admiration to distaste within a year or so once it saw the Cummins engine in action.

Too, Daimler did not have an established position in the single-deck market, when compared with AEC and Leyland or even Guy. It was late to enter the heavy underfloor class with the Freeline in 1951, and never did any major updates to this chassis, nor did it offer a lighter version. The Fleetline double-decker demonstrated that Daimler could “break-in” to an established market with the right product, although in this case AEC’s failure to offer a rear-engined double-decker did provide a ready-made “gap” for it to fill. A major element in the Fleetline success (which I imagine to some extent offset its gearbox problems) was that it had the Gardner 6LX engine as standard. That was Daimler’s “ace”; it would have done better to have engineered its rear-engined single-decker around the 6LX.

The Cummins vee engines had a relatively short period of prominence. But Cummins learned well from its British experience. The later L10 in-line six was designed to match the Gardner in fuel economy, and generally to appeal to the British bus operators, in which role it was very successful. It was also an early example of an engine with smaller displacement but a robust structure more in line with those hitherto used for the larger engines.

Cummins was not alone in not doing too well with its high-speed vee engines. The Perkins V8 had a patchy record, although here operator expectations may have been less. In fact by historical Perkins standards, established with the P6 and R6, it might have been a relatively god engine. The AEC V8-800 was another failure, although allegedly with a lot of get-up-and-go when it was working.

Regarding the Roadliner driveline, there is certainly evidence that the close-coupled form of the fluid coupling and epicyclic gearbox combination could be troublesome when subjected to continuous high loads and perhaps inadequate air flow exposure. This was the case with the “Two-Pedal Beaver” and “Mandator V8” trucks. But with the Cummins V6 set at the lower, “bus” rating, it shouldn’t have been a problem.

When all is said and done, though, the total market for the British rear-engined single-decker chassis (i.e. not including the National) was not all that large, particularly when compared with the underfloor variety. One can debate the relative merits of the Bristol RE, Daimler Roadliner and the Leyland “Swanther”, but the evidence is that all were comprehensively eclipsed by the Mercedes Benz O.305.

Cheers,

[RK215]

Can you explain how the 760 Swift chassis came about.It was the last AEC offered on the Australian Market .Around 60 entered service with the gov't buses in Adelaide in 79 (the year of AEC's closure)and the rest went to various private operators. I am not aware of any other country that ran them,England included.
I have heard they were diverted from Durban ,South Africa but that is all I know to date.Any details of how that model came about would be appreciated.

The Swift 760 superseded the Swift 691 around 1972-73, about the same time that the Reliance 760 superseded the Reliance 691.

The Swift 505 and Reliance 505 were also withdrawn in the same time period, due to the cessation of production of the AH505 engine.

The A691 and A760 formed a pair of engines, released late in 1964, that were the dry-liner successors to the A590/A690. Apparently the AV691 didn’t do too well in truck applications, partly due to its relatively thick liners impeding hear dissipation, and was quickly dropped from the heavy truck range (Mandator and Mammoth Major) in which the AV760 became standard, although typically derated somewhat. The AH691 was usually set at reduced power output for bus applications, so presumably fared better than the AV691. By the early 1970s, bus production at Southall was in the minority as compared with truck production. The switch from the AH691 to the AH760 was essentially a standardization activity.

Although the Swift was withdrawn from the home market in favour of the National fairly early on, it did remain available for export. This is in contrast to the Panther, which was withdrawn altogether. I suspect that the Swift was built only sporadically from 1972 until the Southall closure in 1979. Durban was an early user of the Swift 760, but I do not know the circumstances of the later order, or its apparent cancellation and diversion of the chassis to Adelaide. However, Durban was the location of the AEC South Africa ckd assembly plant, predating AEC’s acquisition by Leyland. One of its main products was the Kudu bus chassis. Given that through the 1970s, AEC was sending Swift running units to UTIC in Portugal for building into integral buses; it just may have been easier to send units to Durban for assembly than to build a big order at Southall.

As a sidebar, the Perth Panthers were built pretty much at the end of Panther production, but it was an order that really could not be turned down. That might explain why this group had a rear-mounted cooling system. It might have been more convenient to fit the Swift cooling system, particularly if parts were already in Southall stock, than to specially build another lot of Panther components. It would be interesting to take a close look at the chassis, to determine whether they were modified Panthers or effectively Swifts with O.680 engines. And also, whether Perth’s 1960’s experience had determined that the Leyland 680 engine was a bit better than its AEC counterpart, which I think is the typical conclusion, and if so would have pointed away from simply buying the Swift 691.

Cheers,

[tbc1983_]

^^^Herb', take note of that (regarding RK215's post on "blunderbus") in any future edition of "Shake, Rattle & Roll", please!

RK215, thanks for that invaluable info!!!


Cheers!

[Herbert]

Great stuff once again RK215.

MTT records show No 10's engine to be VIM200 model. Is that in accord with information available to you?

[Swift]

Totally fascinating reading as usual RK215.Thankyou for demystifying the origins of the Swift 760 and other AEC models as well.
On that Cummins L10.Did Cummins actually design the L10 engine specifically for the British market and was it all done in America?
Am I reading it right that Cummins looked at the Gardner's economy when they came up with their engine?
The Gardner was always seen as a premium engine yet was always eclipsed in the power figures by the Cummins L10 in the MCW Metrobuses.
Was the L10 just as durable as the venerable Gardner product?
I understand that the Gardner range were a very old design being carried on by the 1980s whereas the L10 would have been much more recently designed altogether I assume.
What about the Rolls Royce diesels used in some MCWs as well.Why weren't they as prolific as Gardner /Cummins??

[RK215]

Great stuff once again RK215.

MTT records show No 10's engine to be VIM200 model. Is that in accord with information available to you?

Yes. Actually, I had forgotten about the "VIM" bit, as this engine was often simply referred to as the V6-200, just as the "big" V8 was referred to as the V8.300.

In this series there was VALE, VIM, VINE, etc; I'd really have to think to match these designations to the engines, although VALE was probably the small V8.

Something I haven't retained in the memory bank is whether or not the V6 had a balance shaft or shafts to offset the inherent strong pitching motion that a three-throw crankshaft engine has. (Like an in-line three in that respect.) Even so, the uneven firing intervals incurred by the 90 degree vee/three-throw combination would create severe torque oscillations, and I now wonder if these were antagonistic to the fluid coupling and Wilson gearbox combination. I must admit I hadn't thought of that before. It's amazing how thought-provoking these forums can be.

Cheers,

[RK215]

Totally fascinating reading as usual RK215.Thankyou for demystifying the origins of the Swift 760 and other AEC models as well.
On that Cummins L10.Did Cummins actually design the L10 engine specifically for the British market and was it all done in America?
Am I reading it right that Cummins looked at the Gardner's economy when they came up with their engine?
The Gardner was always seen as a premium engine yet was always eclipsed in the power figures by the Cummins L10 in the MCW Metrobuses.
Was the L10 just as durable as the venerable Gardner product?
I understand that the Gardner range were a very old design being carried on by the 1980s whereas the L10 would have been much more recently designed altogether I assume.
What about the Rolls Royce diesels used in some MCWs as well.Why weren't they as prolific as Gardner /Cummins??

You know, many years ago I did read about the development history of the Cummins L10, but I don't recall enough of the detail other than what I have already said to do justice to your questions. (Maybe I need to eat even more salmon than I already do to improve an ailing memory - goes well with a good Margaret River cabernet, strictly for its antioxidant content of course.) I'm not sure that I've retained much in my library on the L10, either, but I'll check when I'm back home and post again, and also comment upon Gardner and Rolls Royce.

Cheers,

[Dennis96]

Come to think of it, the MTT's Daimler Roadliner's engine was extremely rough, especially at idle. The vibrations may not have helped the longevity of the ancillary components.

And those components do often suffer from excess vibration. For example, the Western Australian Government Railways found this to their detriment with their Crossley V8 engined X class diesel electric locomotives. Identical electrical components that rarely gave trouble in other classes of locomotive with different engines were yet another cause for trouble with the X's. Radiators cracked and leaked and the vibration caused joints in air, oil and coolant pipes to chafe and leak where they passed through bulkheads etc.

[tbc1983_]

Weren't the Crossley V8s meant for submarine use, rather than for land transport use? You hear that all the time with sub/marine diesels being used for land purposes...the damn things overheating, leaking with oil, etc. A lot of post WW2 diesel locos from would-be loco builders (the not so good builders, I mean), trying their luck in the respective market, tried powering locos with submarine diesel engines and usually not with favourable results. I think it's because of the fact that the working environment is far different, that is, instead of using the surrounding water as a heat sink, you only have a closed system (i.e. a heat exchanger) available for cooling, resulting in engine failures, e.g. seizures from overheating, expanding moving parts, plus the leakage of overflowing oil; everybody forgets that lubrication oil needs clearance when heated, even during a "normal" working load, so the tolerances and fittings will have be selected to suit.

Lube oil has 4 uses:

1. Lubrication
2. Cleans (the parts)
3. Protects (parts against corrosion)
4 Cools (the parts)

Enough of my chatter...

Cheers!

P.S. I've walked from one end of an XA to the other, since they'yre bi-directional, at the ARHS at Basso and bloody hell, there's next to no room inside, even in the cabs and I'm only 180cm (5'11'').

[RK215]

Whilst the submarine connection is often quoted in connection with the Crossley HSTV8 engine, I don’t recall seeing anything to substantiate this. It could be that the WAGR X was in fact its first application of any kind. I have the Crossley brochure on the CIE A class, but it doesn’t give any clues to the origin of the engine. Nor does the MetroVick brochure on the X, or any of the trade periodical articles that I’ve seen on the HSTV8-engined locomotives. When I get a chance, I’ll check through “Diesel Railway Traction“ for the 1950s just in case there is an article on the engine itself that I’ve previously missed.

Talking of internally cramped locomotives, try “walking” through an NZR Dg class. And the KTM 22 class isn’t that much better. To a large extent it’s a loading gauge issue. However, in contrast, Sulzer took pains to make its CMT gauge designs as uncluttered as possible within loading gauge constraints, and I gather that the CR NSU was a good example of this approach.

Another relatively rough locomotive engine was the EMD 8-567CR, even though the “R” suffix indicated the rebalanced version. The NZR Db class (EMD G-8 model) was really bad for noise and vibration, especially when operated in MU pairs. In this case I don’t know if there were consequential effects. Those electrics by “Flashover Inc.” might not have noticed the difference, anyway.

Regarding the Cummins V6.200, although the Daimler Roadliner brochures generally don’t give too much information, I found one French language version (for the Belgian market) that includes a cutaway drawing of the engine. There is no obvious evidence of a balance shaft or shafts, although absence of evidence is not evidence of absence. One would need to find some Cummins original literature to be sure on this point.

Cheers,