226
N. A . ISOLME
sampler) and a turn of rope put on it. With a compact grab like the
Petersen thcre is nothing to hold on to, and one must just get out of
the way (Fig. %9). The boom should be swung out so that the grab
comes up just touching the sidc of the ship. In this way i t ha5 less
chalice of swinging oiit of coiitjrol arid may bc pulled in without swinging
the boom when it, is e h v e tlw mil. Unlcss spccisl equipment is avtlilable
it will not, I)(. possibblo to swing the h o r n inboard when the grab is to
Fxa. 30. Working deck of Veleto I V showing the pneumaticdy-operated A-frame
with orange-peel grab open and lowered into ita receiving tub. The Campbell
grab is seen on the right. (From Hartman, 1955. Pholo: Allen Hancock Foundation
of the University of Southern California.)
be lowered on deck. Probably the best way of handling both dredge
and grabs is to have a swinging gallows or A-frame (Fig. 30), operated
by hydraulic or pneumatic equipment. Under this system the grab is
011 a short scope, where it is easily controlled, and it may be rrwung
inboard and lowered to the deck without difficulty. An alternative
method of handling a grab is shown in Fig. 18.
Thorson (1962) illustrates the working of a dredge from a davit
placed o w r the stern, which may be a convenient arrangement where
the rail can be cut away in the manner shown (part of the davit, is
visible in Fig. 9, right).
N. A . ISOLME
sampler) and a turn of rope put on it. With a compact grab like the
Petersen thcre is nothing to hold on to, and one must just get out of
the way (Fig. %9). The boom should be swung out so that the grab
comes up just touching the sidc of the ship. In this way i t ha5 less
chalice of swinging oiit of coiitjrol arid may bc pulled in without swinging
the boom when it, is e h v e tlw mil. Unlcss spccisl equipment is avtlilable
it will not, I)(. possibblo to swing the h o r n inboard when the grab is to
Fxa. 30. Working deck of Veleto I V showing the pneumaticdy-operated A-frame
with orange-peel grab open and lowered into ita receiving tub. The Campbell
grab is seen on the right. (From Hartman, 1955. Pholo: Allen Hancock Foundation
of the University of Southern California.)
be lowered on deck. Probably the best way of handling both dredge
and grabs is to have a swinging gallows or A-frame (Fig. 30), operated
by hydraulic or pneumatic equipment. Under this system the grab is
011 a short scope, where it is easily controlled, and it may be rrwung
inboard and lowered to the deck without difficulty. An alternative
method of handling a grab is shown in Fig. 18.
Thorson (1962) illustrates the working of a dredge from a davit
placed o w r the stern, which may be a convenient arrangement where
the rail can be cut away in the manner shown (part of the davit, is
visible in Fig. 9, right).