AT THE HEART OF THE ROAD TRANSPORT INDUSTRY.

Call our Sales Team on 0208 912 2120

The mechanical aids to vehicle recovery

8th May 1982, Page 30
8th May 1982
Page 30
Page 31
Page 30, 8th May 1982 — The mechanical aids to vehicle recovery
Close
Noticed an error?
If you've noticed an error in this article please click here to report it so we can fix it.

Which of the following most accurately describes the problem?

Bill Brock casts his eye over the range of electric winches, hydraulic pumps and inflatable cushions that recovery operators can bring to immobilised vehicles

VEHICLE recovery operators have done much to improve their image in recent years. They formed a professional association in 1977 (the Association of Vehicle Recovery Operators — AVRO), and many have made a large investment in the latest recovery equipment.

These moves have been well received by the industry. The last thing any transport operator wants is to have his vehicle damaged while it is being recovered and then suffer the indignity of having to pay for the privilege. And as the proposed heavier weights are bound to make some accident recoveries even more difficult for the inexperienced or ill-equipped recovery operator, these people will become all the more appreciative of AVRO,

The C. F. Holmes Corporation of America is one of the best known manufacturers of vehiclemounted recovery equipment.

In Britain, Crane Fruehauf, the Norfolk company better known for its manufacture of trailers, is the sole distributor of C. F.'s range of both mechanical and hydraulic units. These can recover and tow the smallest private car or the heaviest commercial vehicle.

Each installation can be tailor made to suit the size and type of chassis, and may include bodywork with storage compartments and lashing points. Additional items such as beacons, suspended towing attachments and dollies can also be specified.

Typical of the C. F. Holmes heavy duty range is the Victor 1801 model, rated at 45 tons. A single, hydraulically powered boom provides both elevation and extension with loadings up to the maximum imposed.

The single-stage extension, powered by a 139.7mm (5.5in) diameter hydraulic ram, gives up to 8ft movement while a 60° angle of elevation is provided by two 152.4mm (Gin) diameter cylinders fitted with a counter-balance valve for added safety.

At the light end of the Holmes range, the Cadet recovery unit will match small chassis such as Land Rover or the Ford Transit and A-Series and enable them to recover cars or car derived vehicles. The electro-hydraulic boomlift system and electric winch has stylish bodywork.

Bodywork on all vehicles is designed with short rear overhang to maximise on towing capacity while angled rear bumpers improve clearance for close towing articulation. Non-slip material is provided in all floor walk areas while ancillary items such as lamps and operating handles are recessed for protection.

For the large fleet user, the C. F. Holmes fifth-wheel-mounted tow unit readily converts a maximum weight tractive unit into a useful recovery unit.

The Bulldog Dominator, designed and manufactured in England by Wreckers International of Hertford, claims to combine the versatility of the twinboom recovery unit with the advantages of hydraulic power.

A pair of hydraulic pumps, driven from the pto from the vehicles gearbox, allow individual control of the two winches. Alternatively, they may be used as a pair working in either of two directions.

The air-operated controls are said to be light to use even with the heaviest loads. The mainframe supports the booms so that all winching forces are distributed through the subframe which attaches the system to the vehicles mainframe and is designed to withstand winching loads of up to 300 kN (30 tons). Maximum power can be applied through an angle of 180°.

180mm (71n) square section booms incorporate a 100mn (41n) diameter inner sectior equipped with a square heavl duty end plate. When entered the base of the undrilled inne boom rests on the location pin ir one of the three positions. Full) extended, they can be used to ether or singly to the rear or ide up to maximum height, ontrolled by the boom support ables.

Side stabilisers fitted on either ide of the mainframe can be sed individually or together to rovide a solid base for side perations.

The body forms an integral art of the overall design.

There are Bulldog models to uit chassis from 2 to 30 tons. ;ulldog 10, based on the 12-16 an gvw chassis, comes in the Addle of the range and is said 3 be capable of handling gross /eights of up to 25 tons. Overall, le design follows the pattern et by the larger models incor'orating twin booms, separate winches and out-riggers.

Under ideal recovery condions, the twin 187mm (5in) quare section booms are used s a pair for maximum strength; ndividually, they can move lutward through an arc of 120°. hsconnection of the cables for he boom end pulley allows 230° winching from the mainframe.

A reinforced tail gate incorpoates tow loops for winching hrough snatch blocks, brackets or suspended tow, as well as ow jaw, airline and electrical :onnections.

Air bags have been sold by Vreckers International over the ast 10 years. They have been of )articular benefit in righting !elides containing hazardous, rr delicate loads.

The Safelift air cushion system lives a further option for the re;overy operative. It is claimed hat in 90 per cent of cases it is aossible to right a vehicle with out unloading it or inflicting further damage.

The Safelift range contains three types of square-based units. The "starter" cushion has an inflated depth of only 305mm (12in); a wedge shaped cushion is designed to be used in conjunction with a conventional recovery vehicle; and the full size cushion can be used to complete the vehicle righting process.

Top and bottom surfaces are covered in a high grip rubber and the two large bags contain internal reinforcing so they remain rigid when inflated.

Inflation rate should be less than 50 cu ft per minute at less than 30 psi with internal pressure of each cushion restricted to a maximum of just 7 psi. The three types, SQ1, SQ7, and SQ10 have individual vertical lifting capabilities of 6,300 lb, 16,128 lb and 16,128 lb respectively.

There is often more than one solution to the recovery problem of an immobile vehicle, as is demonstrated by the truck and coach recovery system manufactured by Brimec UK Ltd of Bristol. The system, consisting of a tipping body mounted to a rigid or semi-trailer chassis, does not suffer the same speed limitations as a tow and allows the vehicle to be recovered in the direction of traffic flow.

The step frame semi-trailer with a low departure angle of 7°, provides particular advantages for vehicles with long overhangs such as coaches, which can be winch-loaded without damage to expensive bodywork.

Brimee's lift and tow system for car recovery has recently been improved to give a better load angle so as to clear the spoilers now fitted by many car manufacturers.

The Brimec towlift is powered by electro hydraulics. A main beam containing a spectacle frame lifts and tows a car or light van by its front wheels.

Tags

People: Bill Brock, Bulldog
Locations: Bristol

comments powered by Disqus