Fig. 91
It is claimed that no wedges are required for tightening wire rope lashings, as they do not shrink or swell; on the other hand, owing to their small circumference, they cannot be pulled very tight by the workmen, and it is questionable if they would bear being twisted round the scaffolder’s hammer without injury.
Accidents also might happen if the poles shrank at all after being fixed.
Tests have been made from which it has been estimated that each lashing will carry a direct load of 6 tons.
A chain and bracket arrangement for tying ledgers to standards is shown on [fig. 92]. It is easily and rapidly adjusted, and is tightened by means of screw nuts at A and B.
Fig. 92
Permanent injury might, however, be done to the standards by the cutting in of the brackets when screwed up, especially after regular use. The possible loss of the parts and their weight and consequent disadvantage in transport are against their general adoption.
Tightening Screws.—Tightening screws or coupling links ([fig. 93]) are fixed in the length of chain that connects the guys of the Scotch cranes to the base of the queen legs.
