Cranes driven by shafting, or by mechanical power, have been largely superseded by electric cranes, principally on account of the much greater economy of transmission.
The driving power is applied by shafting through a number of cams. In the Royal Mint both light and heavy coins are returned to the melting pot.
The combination of ductility, which lessens the tendency to break when overstrained or distorted, with a very high limit of elasticity, gives it great value for shafting, the merit of which is measured by its endurance of the repeated stresses to which its rotation exposes it whenever its alignment is not mathematically straight.
The alignment of marine shafting, changing with every passing wave, is an extreme example.
C. Greenhill treated the problem of the centrifugal whirling of an unloaded shaft with different supporting conditions in a paper On the Strength of Shafting exposed both to torsion and to end thrust, Proc. Inst.
The independent system of motors is generally adopted, because it is found more economical and better for driving purposes, besides dispensing with the overhead shafting and belting, always unsightly, and dangerous to the workpeople.
The stationary engine at the workshop entrance powers the line shafting.
The unit would, of course, have required suitable ancillary drives--from overhead line shafting for example––to accomplish this.