Three More from Thornyeroft
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Swift 4-tonner, Trusty. Maximum-load Fourwheeler and Big Ben 6 x 6: Final Version of • Eight-wheeler: New Engine THREE new models will be featured by Transport Equipment -(Tharriyeroft), Ltd., at Earls Court this year. These consist of the Swift OL/JR6 7-ton-gross and the Trusty VLJNS6 14-ton-gross four-wheelers and the Big Ben SLDN/KRN6/S ' 6 x 6 normal-coritrol chassis. The Big Ben, which has a turbo-bloWn oil engine, is of such massive proportions as' to h' likened to a smaller version of the Mighty Antar.
In addition to the three completely new models, the final produetioo, version of the Trusty P.K/QR6 eightwheeler will be seen, together with a , . .
normal control left-hand-drive version „. ,
of the overseas Trident (PON/CR6/1) chassis and the Swiftsnre IIL/JR6 platforM lorry with a glas-fibre cab, The Swift will be exhibited in the denton7, stration park; together with a home model. Trident and a Swiftsure with Metal cab,
The Swift is a 4-tonner with a similar Mechanical specification to that ofthe Swiftsure. Its impending produc-' lion Was hinted at during the Scottish Motor Show last November and the Chassis is now in full production:• It is powered :-bythe JR6 six-cs„.lindered direct-injection oil • engine, which develops 80 b.h.p. at 2,600 r.p.M. with a maxiMum torque'-output of 184 lb.4t. at 1,600: r.p,m.
A 12-in.-diameter single-dry-plate clutch and four speed gearbox. arc ernploYed, and the fully floating sPiralbevel real axle has a standajd ratio of 5.857 to 1. An alternative ratio of 5.156 to 1 is offered. Two-leading-shoe hydraulic brakes are used, with by 21-in. units on the front 'wheels and 151-in. by 31-in, rear-wheel units. No servo is fitted.
The Swift has a wheelbase of I3_ft. 6 in and the recommended .maximum body length is 16 ft. 7 in. With the standard 7.00-20-in. (10-ply) tyres it has a grosS ladeTh weight. rating Of 7 tOns., In licensing condition the chassis and
cab weigh 2 tons 64 cssit. .
AS demonstrated at Earls Court, the Swift will have a plastics cab. This is built on to the standard all-metal cab base and consists of a one-piece roof
and rear panel and plastics doors. It is about 1 cwt. lighter than the standard all-steei cab.
The Trusty 14-ton-gross forwardcontrol chassis is additional to the VF 15-ton-gross overseas four-wheeler already in production. It has been designed from the start as a maximumload four-wheeler to suit the amended British weight limits and employs a new six-cylindered oil engine—the NS6— which_ is similar to the old NR6 unit, but has a higher power rating and a lower weight. • Thus, the NS6 develops 109 b.h.p. at 1,800 r.p.m. and 354 lb.-ft. torque at 1,000 r.p.m., compared with the 100 b.h.p. and 333 lb.-ft. torque of the NR6. Weight has been saved by the extensive use of aluminium alloys, but many components remain common to both units.
This engine has a new type of lubricating-oil pump drive, which is also found in the JR6, QR6 and KRN6 units. Instead of being driven through skew gears from the camshaft, the pump is now mounted on the lower face of the timing-gear cover, inside the sump, and is driven by helical gear from the front of the crankshaft.
Easy Removal This arrangement has the advantage that the pump can be easily removed in case of trouble, and the larger gears now used give a more positive drive with correspondingly less risk of the drive shearing in cold climates.
The engine of the VLINS6 chassis carries a I4-in.-diameter single-dry-plate dutch and is mounted as a unit with a new design of four-speed gearbox_ This has constant-mesh gears, with ratios of 6.91, 3.36, 1.64 and 1 to 1, the reverse ratio being 8.25 to.!. An open two-piece propeller shaft takes the drive to the overhead worm of the rear axle. This worm drive has 7f-in. centres and gives a reduction ratio of 5.5 to 1.
An air-hydraulic braking system is employed. The front wheels have 16fin. by 4f-in. brakes and 151-in. by 6-in. units are fitted at the rear. The Merles cam-and-double-roller steering gear has Clayton Dewandre hydraulic
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assistance. The Plessey hydrauliapump which provides the power for this.steering gear is driven from the timing gears in tandem with the dynamo.
A 16-ft. 6-in.-wheelbase chassis will be seen on the Show stand, but a 12-ft. 6-in-wheelbase version is also available. The frame is substantial, with six cross-members, • The side members have a maximum depth of 10411-in., and 3-in.-wide flanges. The top of the frame is flat.
• The standard tyre equipment is 10.0020-in, (14-ply). The approximate cab and chassis weight in licensing condition. is 4+ tons, which will allow an 8+-9-ton payload, according to the type of body fitted. The maximum recommended body length on the Show chassis is 21 ft, 6 in.
The Big Ben exhibit marks the introduction of a new series of these vehicles. The many variations are too, numerous to describe, but briefly consist of normal and forward-control 6 x 4 and 6 x 6 load-carrying and tractor chassis, which may be powered by turbo-blown or normally aspirated oil engines.
A normal-control 21-ft.-wheelbase 6 x 6 with blown engine will be exhibited at Earls Court. This has a maximum gross weight rating of314tons as a solo machine, or 50 tons with trailer. The large Kirkstall rear bogie has double-reduction axles with hypoid primary gearing and epicyclic secondary reductions. The front axle has a spiralbevel and epicyalic double-reduction unit and the common axle ratio is 10.18 to I. Semi-elliptic springs are employed at front and rear, the bogie springs being inverted.
The KRN6/S engine develops 200 b.h.p. at 1,900 r.p.m., and the-maximum torque output at 1,000 r.p.m. is 625 lb.-ft. The turbo-blower is an Eberspacher design. The engine carries an 18-in.-diameter single-dry-plate clutch with an air-pressure servo. The main gearbox is a four-speed unit with ratios of 4.80, 2.73, 1.66 and I to 1, and a three-speed auxiliary and transfer gearbox is incorporated in the transmission. This gives ratios of 2.52. 1.33 and 0.84 to I. Hydraulic power assistance is provided for the steering. Clayton Dewandre equipment is used and the power ram acts on a steering relay lever
forward of -the steering box. Airpressure braking is employed.
. The Big Ben is fitted with 14.00-20-in. (18-ply) tyres.' Optional extras include two power-take-off gears, a 50,000-lb. winch and towing attachments, and airbrake -connectiOns for trailer working.
A PKQR6 eight-wheeler will be shown in 8'x4 form, but an 8x 2 version is .available. The chassis specification has altered little from that of the chassis first seen at the Scottish Show last year, but a new five-speed gearbox is fitted, as opposed to the four-speed main and
two speed auxiliary units used ureviously. " An additional overdrive ratio is available as an optional extra on this five-speed gearbox.
A maximum power output of 130 b.h.p. at 2,000 r.p.m. is specified for the QR6 9.83-litre six-cylindered direct-injection oil engine, and the peak torque output of 430 lb.-ft. occurs at 1,200 r.p.m. Twin oil-bath air cleaners are mounted directly on the induction manifolds, where they obtrude less into cab space and are less 'noisy.
RockingBeams
Rocking-beam four-spring suspension carries the rear bogie and the centre bearing i of the beams consist of triple Metalastik rubber bushes. These allow a maximum deflection of 20°, although each bush is limited to a 10° deflection, The overhead-worm driving, axles in double-drive bogies have 71-in. centres, but when a single driving axle is employed, an 8f-in.-centre final drive is fitted.
Steering effort is reduced by power assistance, and the air-pressure brakes operate on all four axles—an unusual feature in British eight-wheelers.
The QR6'engine fitted to this chassis and the KRN6 and KRN6/S units have a spring-loaded pinion which can be pushed into mesh with the starter ring on the flywheel and turned by a spanner to time the engine.