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A steam crane is a crane powered by a steam engine. It may be fixed or mobile and, if mobile, it may run on rail tracks , caterpillar tracks , road wheels, or be mounted on a barge. [ citation needed ] It usually has a vertical boiler placed at the back so that the weight of the boiler counterbalances the weight of the jib and load.
Quill stem classic single-piece type Threadless stem shown with cable hole. The stem is the component on a bicycle that connects the handlebars to the steerer tube of the bicycle fork. Sometimes called a goose neck, [1] a stem's design belongs to either a quill or threadless system, and each system is compatible with respective headset and fork ...
A level-luffing crane is a crane mechanism where the hook remains at the same level while luffing: moving the jib up and down, so as to move the hook inwards and outwards relative to the base. [ 1 ] Usually the description is only applied to those with a luffing jib that have some additional mechanism applied to keep the hook level when luffing.
The external lewis was originally shaped like a pair of scissor-tongs, and swung from a treadwheel crane. [3] This type of tong device has been known as dogs and the holes in the stone as dog holes for many centuries. Many old bridges and walls in the UK still have dog holes to reveal how the stones were lifted, particularly onto bridge ...
As the capacity of the crane was so obviously limited by its motive power, not its strength, they were an obvious candidate for steam power – as was later re-applied to the 60 ton crane at Keysham. There was even a proposal for a 120 feet (36.6 m) high crane, to replace masting sheers at Woolwich. A more typical size for most of these later ...
In 1959 crane expert R.H.Neal, hydraulics specialist F.Taylor, and design director Bob Lester, integrated all three and modernized cranes. The Coles Hydra Speedcrane appeared in 1962, further modified with the 10-ton fully telescopic hydraulic boom in 1966, followed in 1968 by the 30-ton "Husky" military versions with four-wheel drive. In 1972 ...
This was a rail-mounted steam crane, with a fixed horizontal jib carrying a movable trolley or 'crab'. The crane, including the steam plant, could slew on a central king post bearing. This represented all the main features of the fully developed block-setting crane, although at a small scale as yet.
A jib or jib arm is the horizontal or near-horizontal beam used in many types of crane to support the load clear of the main support. [1] [2] An archaic spelling is gib. [3] Usually jib arms are attached to a vertical mast or tower or sometimes to an inclined boom.