Lashings are seizings of rope for heavy work, such as scaffolding; and the lashing of poles, ledgers, and putlogs may be now considered with advantage. Heavy scaffolding is best lashed with chain; and it should be noted that, while a rope lashing is hove taut by the steady strain of a heaving bar, a chain requires different treatment, and must be jerked tight with little tugs—an action similar to that used when shaking out a mat—assisted by an occasional rap with the heaver.
The rope used for lashing all parts of scaffolding should be fairly new, sound, and in size not more than 1½ in. The average length required will be about six yards, and it must be so put on that each turn of the lashing takes its share in the support. To this end the tackle supporting the ledger must not be released until the lashing is completed, otherwise the first turns will be subjected to undue strain.
Fig. 171 shows the lashing of a ledger to a pole; if chain is used a different method is necessary, and it is lashed as in Fig. 172.
Putlogs should be square, or at any rate flat on the upper and lower sides, to prevent any chance of rolling, one end being squared down in size to enter the building in the place of a header brick, the other end being lashed down to the ledger as in Fig. 173. The planks forming the stage are not lashed to the putlogs, and there is great danger in allowing them to project at one or both ends.
Poles are generally about 30 ft. long, and for high buildings it is necessary to lengthen them by lashing on an extra pole. The safest plan is to lash a half pole to the lower part of the first erected; this resting on the ground will form a footing, upon the upper end of which the lengthening pole will stand, being kept in position by three plain lashings (see Fig. 174). Should the lengthening pole be only light, and a footing not be considered necessary, a chain racking should be put on besides two rope lashings.
It is usual to wedge scaffold lashings tight, and, provided the wedges are well shaped, it is a convenient way of tightening the work after change of weather. Badly-shaped wedges are apt to cut the rope and sometimes work out.
Stages for painting, or small repairs on a building, may be quickly rigged up by slinging each end of a plank on the bight of a rope. For this make a marlinespike hitch (see Fig. 40, p. 40), and let the end of the plank take the position there occupied by the marlinespike; the double part will be below and the single part above the plank (see Fig. 175). For single-handed work a boatswain’s chair, of which an illustration is given by Fig. 176, is convenient.