Volvo F86-50 8x4 tipper at 30 tons gvw
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AILSA TRUCKS first introduced the Volvo 30-ton eightwheeler nearly three years ago, but it has taken until now for them to settle on a final specification and start serious production.
In those three years the specification has been modified: the major changes are the replacement of the Watson-designed rear bogie by Volvo's own "T-Ride" bogie; the use of the frame from Volvo's new N-Series bonneted truck range; and the change from Hydrosteer ram power-assisted steering to integral power. The steering unit is now remotely mounted between the front axles. Otherwise the eight-wheeler uses already well-proven components from the popular F86 truck range.
Bare chassis-cab weight of the F86-50 is 8.4 tonnes (8.3 tons), though when fitted with the heavy duty all-aluminium rock-body, built by Edbro, unladen chassis weight is pushed up to 10.4 tonnes (10.3 tons). Specification of a lighter body would reduce unladen weight by as much as 0.5 tonnes and payload capacity would be increased to over 20 tonnes (19.7 tons).
The front bogie is plated to 12,2 tonnes (12 tons), the rear bogie to 19.3 tonnes (19 tons), so there is a full 1 tonne weight distribution tolerance across the bogies at 30 tons gross. Compared with many other makes of eight-wheelers the Volvo, with its compact design, is relatively small and from the environmentalist's viewpoint it has a less forbidding appearance. As tested, the eight-wheeler returned good fuel consumption at satisfac tory overall speeds; the vehicle is easy to drive and the cab comfortable.
Performance
The Volvo's small —6.7-litre (409cuin) — TD7OE turbocharged engine produces just over 200bhp (BS AU 141a: net installed) and the success of its marriage to the eight-speed range-change synchromesh gearbox is already well known.
In test trim the Volvo easily maintained average motorway speeds in the low fifties and on the flatter stretches it could hold its 55 mph plus maximum. Adjustments to the fuel-injection pump to correct the governor cut-in speed from 2,300 to the engine's rated speed of 2,400 rpm were carried out after the first day's tests. So slightly higher maximum speeds than those achieved by us may be expected.
Some operators may prefer to opt for a vehicle offering either more power, lower gearing or a larger clutch, espe cially if their vehicles are engaged on heavy work on sites with steep gradients. The Volvo's clutch needed firm but gentle coaxing to restart the vehicle on a I in 5 gradient in first gear, while in reverse a restart could not be accomplished at a single attempt. The climb would probably have been overcome by a series of restarts, gaining a few feet at a time before the engine stalled. All the hill restart tests were carried out with the incorrectly set fuel injection pump, but I doubt that correct setting would have made any difference.
• The 5.43 to 1 axles fitted to the Volvo are the only ones listed for the eight-wheeler and as there are no gearbox ratio options either, some operators may find the specification marginal. However, for genera: work the specification is well up to the required standard.
Operational consumption
Fuel consumption readings over CM's Midlands test route were consistent with the type of terrain covered, the highest 32.1 lit/100km (8.8rnpg) con sumption being achieved on motorway where the engine was kept at maximum revs so making full use of the turbocharger.
To get a typical operational consumption we completed g run from a gravel pit in Staines (near London Airport) to a drop at Rickrnansworth, about 20 miles away. On the outward leg the Volvo was loaded to 29.4 tonnes (28.9 tons) gross with ballast for the construction of London's North Orbital Road; the return leg was run unladen. The overall 31 lit/100km (9.1mpg) consumption achieved for the round trip included about one hour of idling and shunting time at both the pit and construction site clueing the loading and tipping.
One of the F86's best features is the ease with which it can be driven, and I believe the F86 is a suitable vehicle for training the novice driver. The basic four-speed gate of the gearbox is well defined and the range-change toggle switch conveniently mounted in the gear:ever knob.
Ride and handling
When fully laden I found it easier to pull away in first and then skip out second in the up-change sequence; and when unladen a comfortable restart is made on flat roads from fourth gear. Each ratio step accounts for about 400 engine revs and any lack of power on hill climbs is easily compensated for by taking two, or on rare occasions three, gears at a time during the down-change sequence. Provided the driver is sufficiently used to the vehicle to gauge the correct revs and vehicle speed When taking two or three gears, then optimum performance is certain.
Steering is pleasantly light regardless of whether the vehicle is loaded or not, and initially one could be misled, by the light control, into taking corners faster than one normally would.
Vehicle ride is also exceptionally good and even when travelling unladen over poorly surfaced roads. the driver is insulated from road bumps and vibrations.
Braking with the fully laden 30-tonner is a bit of an anti climax; even when completing an emergency stop from 64km/h (40 mph) the Volvo gently came to a dead stop in just over 100ft without any tendency to swerve and only the rear bogie brakes locking.
Cab comfort
By now the merits of the F86 cab are well known. However, for tipping work its one main advantage is that it is set low to the ground. And this, together with the large step, makes continual alighting and boarding much less fatiguing than with other cabs. Also the excellence of the Volvo rear-view mirrors pays off when you consider how much time is spent reversing, often into tight corners, to tip. The biggest disadvantage of the cab for tipper work is the absence of any useful footholds to gain access to the body, say to trim the load or to shovel off any excess. The body was not supplied with a ladder so the only way to reach the load was to climb on to the hydraulic oil reservoir between body and cab.
Tipping
Inside, the cab is trimmed to the usual Volvo standard and provided the floor covering stands up to the heavy wear from constant buffeting by wet boots and gravel there should be no problem in keeping it clean. The tipping controls are mounted just below the dash in the middle of the cab and though they are too far away to be reached without stooping from the driver's seat, there does not seem to be any room to put them any closer. The cab rear window is useful for keeping an eye on the load as it is being tipped.
The body tailgate was secured by threaded clamps, one at each side of the body and the conventional, lever operated, locking bar across the bottom edge. Once these were released it took just over Imin 30sec to tip the load and restore the body to the normal running position.
Summary
The Volvo F86-50 is built from components already well proven in service and apart from its hill restart performance, which some may consider to be marginal, it puts up a good all-round performance. It is easy to drive, the cab is comfortable and quiet and the vehicle payload capacity matches that of competitors.
As tested the Volvo chassis costs £15,068 plus a £250 currency surcharge which is added after discount. The price of the Edbro body including gear and pto and fitting is £3,159.