Iron Fairy 65ft jibs
Page 34
If you've noticed an error in this article please click here to report it so we can fix it.
• Additions to the Iron Fairy range of mobile cranes from the British Hoist and Crane Co. Ltd. (part of the 600 Group) include the Zircon and Cairngorm. Both are capable of lifting 10 tons. The Zircon is a truck-mounted crane-on a three-axle, twin-steer chassis ---while the Cairngorm is a two-axle mobile crane with four-wheel drive and at-wheel steering.
Features common to the two designs include the hydraulic jib which is 65ft long and is in four telescoping sections giving a height under the main hook of 69ft and 85ft under the fly-jib hook. The jib is fully-powered for its full length and is fast in operation with a single-fall line speed of 200ft per minute. An angle of 80 degrees to the derrick means that even when fully extended, a load can be handled only 4ft from the crane. As there is no counterweight, this allows both cranes to work in confined conditons that would be impossible for many designs.
The Zircon has a heavy-duty chassis designed specially for the model by Vickers All Wheel Drive. It is fully sprung and meets all regulations, including plating. Each of four hydraulic outriggers can be operated individually and they can be extended quickly for blocked duties. For free-on-wheels craning the suspension can be locked up.
The engine in the Zircon is a Bedford 466 cu.in, diesel giving 144 bhp gross (BS) and the drive is through a five-speed gearbox. Full air brakes are fitted with split circuits and there are spring brake units at the rear axle for parking. Running weight is 17.5 tons and a maximum road speed of 46 mph is possible.
The Cairngorm is completely manufactured by British Crane and Hoist and has Kirkstall front and rear driven axles. The engine and transmission are as the Zircon but kerb weight is 19.5 tons and the front axle is rigidly mounted while the rear is pivoted at the centre to allow 12in. articulation on each side. The driver can select four-wheel drive or rear-wheel drive or front-wheel drive only and he can select four-wheel steer, twofront-wheel steer or "crab" steer. In the last case all wheels can be turned in the same direction to their maximum angle of about 45deg and the crane moved sideways. With all-wheel steer a turning circle of 30 ft is claimed.
When blocked—with their outriggers extended—the Zircon and the Cairngorm have comparable lifitng characteristics. The maximum load of 10 tons is possible at a radius of 10ft, 4 tons can be lifted at 1-8ft radius to a height of 51ft and with fly fib and fully-extended main boom, 1.5 tons can be raised to a height of 83ft at 17ft 6in. radius. Free-on-wheels, the Zircon has a capacity of 4 tons at 10ft radius and 1 ton at 18ft 6in, while the Cairngorm retains its blocked capacity when lifting over the cab and has figures over the sides and rear of 6 tons at 10fit and 1.5 tons at 18ft 6in. radius.
Easy-access low-height cabs are fitted to both models and the list price for the Zircon will be under £12,000 with the Cairngorm costing under £13,000.