The picking-up machinery forward (Fig. 37) after the previous expedition was considerably strengthened and improved with spur-wheels and pinion-gearing. It had two drums worked by a{191} similar pair of 70-horse-power engines. This formed an exceedingly powerful machine, and reflected great credit on those who devised and constructed it.
Similar gear was fitted up on board the two vessels—S.S. Medway and S.S. Albany—chartered to assist the Great Eastern.
For the purpose of grappling the 1865 cable, twenty miles of rope were manufactured, which was constituted by forty-nine iron wires, separately covered with manila hemp. Six wires so served were laid up strandwise round a seventh, which formed the heart, or core, of the rope. This rope would stand a longitudinal stress of 30 tons before breaking.
In addition, five miles of buoy-rope were provided, besides buoys of different shapes and sizes, the largest of which (Fig. 38) would support a weight of twenty tons. As on the previous expedition, several kinds of grapnels were put on board, some of the ordinary sort, and some with springs to prevent the cable surging, and thus escaping while the grapnel was still dragging on the bottom; others, again, were fashioned like pincers, to hold (or jam) the cable when raised to a required height, or else to cut it only, and so take off a large proportion of the strain previous to picking up. Most of this apparatus was furnished by Messrs. Brown, Lenox & Co., the famous chain, cable, anchor, and buoy engineers, several of the grapnels being to their design, as well as the “connections.”
The propelling machinery of the Great Eastern had similarly received alteration and improvement in the intervals of the two expeditions. Moreover,{193} the screw propeller was surrounded with an iron cage, to keep the cable and ropes from fouling it, as had been provided for the Agamemnon and Niagara in 1857.
