There is ample equipment of fixed and movable staiths and cranes of various sizes up to 70 tons, the Lewis-Hunter patent cranes being largely used for shipping coal owing to their minimizing the breakage of coal and securing its even distribution.
Hoisting ropes are weakened by deterioration and breakage of the wires, due to corrosion and repeated bending.
Further, all the subsequent processes of cutting, moulding and annealing become increasingly difficult, owing to the greatly increased risk of breakage arising from either external injury or internal strain, as the dimensions of the individual piece of glass increase.
The headache-post is a vertical wooden beam placed on the main sill directly below the walking-beam, to receive the weight of the latter in case of breakage of connexions.
The mechanical operation is quite successful for thick sheets, but it is not as yet available for the thinner sheets required for the ordinary purposes of sheet-glass, since with these excessive breakage occurs, while the sheets generally show grooves or lines derived from small irregularities of the drawing orifice.