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Foden/York 32-ton gcw artic on

25th May 1973, Page 82
25th May 1973
Page 82
Page 84
Page 85
Page 82, 25th May 1973 — Foden/York 32-ton gcw artic on
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FODENS are now standardizing on their new S80 grp cab and, having already tested a rigid eight-wheeler fitted with it (CM 2 March 73) we have recently had the opportunity of trying it over our long-distance route in artic form. The outfit was a Rolls-Royce Eagle 220-engined tractive unit coupled to a York tandem-axle semi-trailer. The Rolls engine produces 213bhp net installed to BS AU 141A: 1971 and was coupled to the Foden eight-speed gearbox.

This combination produced the best performance results yet achieved by a 32-tonner over CM's Scottish route, some 400 miles of which is motorway, and it is significant that the Foden could run at 60 mph without exceeding 2200 rpm. At the other end of the performance range the vehicle climbed the three steepest hills on the route (each has sections approaching 1 in 6) in second gear, the first gear was never necessary on the road.

The Loden not only achieved a very good journey time but also a very satisfactory average fuel consumption; this worked out at 6.7mpg over the whole test and is 0.5 mpg better than we achieved with the previous 32-ton Foden tested, which had a 14-litre Cummins engine. Acceleration, however, was not so good as with the American engine.

1 found the outfit easy to drive, and the handling — with light steering and a short tandem-axle trailer — was almost as easy as with a rigid.

Cab and controls The S80 cab is by now fairly well known; I described it in some detail on my test of the eight-wheeler, and it features in another article in this issue. We saw half a dozen or so on the road during the test — the cab is immediately recognizable by its 1 tin-diameter headlamps and th( familiar Foden bow-wave design.

Visibility from the S80 cab is ver3 good both to the front and the rear On the test vehicle the nearsidc mirrors were placed well ahead of thc cab screen and as a result remainec remarkably clear of rain and dir when we ran through some prettl dirty weather. The line of vision to till mirror is through the wiped area o the left-hand screen — unlike um situation on some trucks where z clean mirror is obscured by a dirt■ window and thus good rearwarc visibility was maintained even in bac weather.

The offside mirror position is a bi of a compromise because of titi unusual position of the doorpost However, placed as they were th. mirrors could be cleaned easily anc did not obscure vision when enterini a roundabout.

Instead of external ram assistance the steering on the test Foden was by the Burman integral power steering unit which, to my mind, has wiped out all cause for complaint about the vagueness which has sometimes afflicted Foden steering.

The steering is both light and precise, the number of turns of the steering wheel from lock to lock is only just over four, and the combination of high gearing with light steering makes manoeuvring easy at any speed. The short wheelbase (911 bin) and a good lock give the solo tractive unit a very tight (43ft) turning circle which is really more than can be used on occasions, when coupled, without straining the trailer; turning on really sharp lock has the effect of pulling the leading axle of the semi-trailer sideways before its wheels can move forwards.

At high speed on motorways the steering was light in the central position without being vague and the vehicle ran naturally straight without demanding undue concentration by the driver. On ordinary roads it was at first easy to "over-steer" on the approach to roundabouts, for example, but it took only a few miles to become completely at home with the steering.

From the driving point of view the new cab is well designed and well built but the ride suffers from poor springing and the short, 911 6in, wheelbase. The driver sits high, even by modern standards, and almost over the front axle, some distance from the centre of gravity, and therefore is subjected to considerable pitching movement. The cab and driver's seat are sprung but these springs seem to accentuate bumps rather than absorb them.

On smooth motorways or trunk roads the ride is reasonable enough but even a minor surface irregularity will upset the ride and a discrete bump makes the whole cab plunge.

The ride, then, which was below average for a two-axle artic, detracted from what is otherwise a very well thought out vehicle.

The cab itself, as well as being well laid out from a driving point of view, affords good maintenance accessibility. All normal servicing can be done through opening panels within the cab or through the hinged grille panel and for the bigger jobs the cab can be tilted by a hand-operated hydraulic jack. Before tilting the two bolts holding the radiator have to be undone and the radiator hinged down; also the bolts holding the spring-and-damper cab mounts have to be released. The cab tilt operation, including the undoing of the bolts, took about seven minutes to complete, which is not unreasonable as it would only need to be done occasionally.

Transmission As I have already mentioned, the Foden revealed an unusually good combination of high-speed running and hill climbing during the operational route trial. Checking its climbing powers at MIRA we easily restarted on the 1 in 5 gradient in first gear, and only just failed to restart on the 1 in 4. The fully laden vehicle climbed the 1 in 4 hill in first gear at 2150 rpm without undue fuss. This amazing range of performance results from the ratio spread of the gearbox.

Bottom gear is 12.25 to 1 and top gear is 0.77 to 1, giving a spread of 15.9 to I. Many 32-ton-gcw artics today are using gearboxes with a spread of only 10 or 11 to 1 and as a result either top speed or bottom-gear hill-climbing ability is limited.

Such a large range can mean a large number of gears and this box is still available in its original 12-speed form for tippers and truckmixers but Foden have standardized on an eight-speed version for haulage models. The name eight-speed is a bit of a misnomer as in fact all 12 speeds are still in the box and it is not long before, either by design or accident, the driver finds them.

In fact the power of the Rolls engine suits the choice of the eight gears very well and under normal conditions. the only "extra" gear worth using is third overdrive, which gives a speed of 43 mph. On motorways when approaching a long slope the driver can change down to seventh gear at 48 mph which is very useful for maintaining speed on gradients, but then sticking strictly to the eight speeds he would have to wait until 33 mph before being able to use sixth gear. By staying in the seventh gear position and simply flicking the range-change lever, however, the "missing" third overdrive gear gives a very handy 43 mph. This gear also proved useful on normal trunk road use.

The constant-mesh gearbox gives a fast change which requires very little lever effort. The lever movements are short and precise and give the driver a feeling of confidence in its use. On hills, gears can be missed out with accuracy and, in the underdrive range, gear changes can be made without double-declutching — making progress very good indeed for such a heavy vehicle.

In America and in the UK drivers have tended to prefer the constant-mesh gearbox but on the Continent synchromesh is becoming increasingly popular on heavy trucks on the basis that they require less skill to use. I would be the first to agree that the old Foden 12-speed box with the remote range-change lever was too difficult for the average driver but I rate this new one-stick eight-speed box as being as pleasant to use as the majority of synchromesh designs.

As stated earlier, consumption with the Rolls was a little better than with the Cummins, but acceleration was down compared with the Cumminsengined vehicle — which was also rated at 220 bhp gross — and below average for a 32-tanner. From rest through the gears took 77.8 sec whereas some 32-tonners have bettered 60 sec. I felt that the poorer acceleration might be due to the fewer number of gears and by repeating the acceleration tests using the most advantageous gears we achieved two runs of 70.6 sec and one of 64.4 sec so obviously the use of third overdrive in particular does produce an improvement.

Braking performance was virtually the same as achieved on the previous Cummins engined Foden, and 0.39g average deceleration from 30 mph and 0.42g average deceleration from 40 mph are about average for a 32-ton-gcw attic.

Until June last year four-axle attics running at 32 tons gm had to use a 40ft trailer but since then the introduction of revised C and U regulations has permitted 32-tonners with an internal axle spread (rear tractive unit axle to leading bogie axle) of 4.4 metres (14ft Sin). The test vehicle was fitted with a 10-metre version of York's Lo-deck LD 34 semi-trailer. This type is a platform semi-trailer but has twistlocks recessed into the deck to accommodate one 20ft or one 30ft container. The weight of the container is spread over the platform and the twistlocks are there to give security rather than carry the load, as they would on a platform skeletal.

To sum up, the RollsRoyce-engined Foden has an excellent performance and a good fuel consumption. Used as an eight-speed, the gearbox is a big improvement on the original 12-speed gearbox but I cannot see the point of calling it art eight-speed since all 12 gears still exist. The list price of the Foden tractive unit is £7,000, the radio is £60 extra and the 5th wheel, a York big "D" in the case of the test vehicle. is available factory fitted at £124 extra which is competitive considering the high standard of the specification to which the Foden is built and the length of service it will give.

Enquiries as to the price of the semi-trailer should be made to any York dealer or direct to the factory at Northampton.

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Locations: York

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