Thirty gears for a dual role Atkinson
Page 20
If you've noticed an error in this article please click here to report it so we can fix it.
• The driver of a new Atkinson six-wheel tractive unit, which has lately entered service with Cambro Contractors, of Clay Cross, near Chesterfield, has 30 gears from which to choose. This is because the unit has two distinct types of job to do. Sometimes it has to provide the power for a 60-ton transporter; other times it is operated as a general-haulage tipper at the normal 32 tons.
The Atkinson has an eight-cylinder Gardner 250 hp engine driving through a 15-speed Fuller Roadranger gearbox to two Eaton two-speed rear axles.
The low-loading tri-axle trailer which it uses for the heavy-haulage duty under Special Types Regulations is the first example of a new range of King low-loaders expressly designed for heavy wheeled or tracked loads whether the primary requirement is a long deck or a low deck.
When coupled to the low-loader, the Atkinson is used to carry Cambro's earth-moving motor scrapers, weighing up to 45 tons, between sites. This work calls for a wide selection of low gears, and the lower gearing of the two-speed axles is then used. For running empty between sites the high axle-speed is selected and the outfit can then attain normal traffic speeds. The higher axle speed also affords the correct match of engine and transmission for normal haulage.
The big motor-scrapers 'which the outfit has to carry are used on Cambro's own sites, and as part of the firm's civil engineering plant-hire operation. The trailer for this duty is the new, three-axle low-loader specially produced for such jobs by King Truck Equipment Ltd, of Market Harborough, Leics.
This trailer, weighing 10 tons and grossing 55 tons, has been evolved to meet construction-industry needs for a long low-decked vehicle capable of carrying either motor scrapers or heavy crawler equipment. A low main deck, 24ft long and 2ft high, is married to a 12ft 7in. long deck, 35in. high, over a tri-axle bogie on small wheels. The bogie has its axles at only 44in. centres to keep it compact, avoiding undue tyre scrub and keeping the trailer reasonably manoeuvrable. The wheels have 7.50-15 Michelin X tyres.
The gooseneck at the front is detachable so that plant can be loaded or unloaded over the front end. Later, Cambro intends to have the King Hydroneck fitted. With this the driver can hydraulically raise or lower the front-end of the main deck.
When not required for hea+iyduties, the Atkinson is used as part of Cambro's general haulage fleet of 30 vehicles. Coupled to a tipping semi-trailer, it can carry a payload of about 19 tons within the legal gross weight limit of 32 tons. With the two-speed axles it then has a potential maximum speed of 65 mph. On this work it carries Cambro's own products, which include graphite; limestone, open-cast coat and sand and gravel.