LASHINGS AND TIES FOR SCAFFOLDING.
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.
[Illustration: Fig. 171.—Rope Lashing for Poles and Ledgers.]
[Illustration: Fig. 172.—Chain Lashing for Poles and Ledgers.]
[Illustration: Fig. 173.—Rope Lashing for Putlogs.]
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.
[Illustration: Fig. 174.—Poles Lashed and Wedged, with Footing.]
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.
[Illustration: Fig. 175.—Slinging Plank for use as Stage.]
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.
[Illustration: Fig. 176.—Boatswain’s Chair.]