They counteract in some measure what may be regarded as the dead weight of the wing, and are especially useful in giving it continuous play.
Rankine proved (Applied Mechanics, p. 370) that the necessary strength of a stiffening girder would be only one-seventh part of that of an independent girder of the same span as the bridge, suited to carry the same moving load (not including the dead weight of the girder which is supported by the chain).
Imported column is given the weight of fresh (frozen) mutton and lamb imported, plus the estimated dead weight of the sheep imported on the hoof for slaughter.
Nay, every attempt at genuine amendment was frustrated by the dead weight of a powerful opposition, and when the first captivity came it was precisely the best elements of Judah that went into captivity and were scattered among the nations (xxiv.
The merit of the simple suspension bridge is its cheapness, and its defect is its flexibility: This last becomes less serious as the dead weight of the structure becomes large in proportion to the live or temporary load.
It is largely replacing brass and copper in all departments of industry - especially where dead weight has to be moved about, and lightness is synonymous with economy - for instance, in bed-plates for torpedo-boat engines, internal fittings for ships instead of wood, complete boats for portage, motor-car parts and boiling-pans for confectionery and in chemical works.
In Koepe's method the drum is replaced by a disk with a grooved rim for the rope, which passes from the top of one cage over the guide pulley, round the disk, and back over the second guide to the second cage, and a tail rope, passing round a pulley at the bottom of the shaft, connects the bottoms of the cages, so that the dead weight of cage, tubs and rope is completely counterbalanced at all positions of the cages, and the work of the engine is confined to the useful weight of coal raised.