MKT V-22/HP-380T4, Руководство по эксплуатации, техническому обслуживанию и каталог запасных частей

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VI. OPERATING INSTRUCTIONS (CONTINUED)
B. OPERATING THE V-22/HP-380T4 SYSTEM - EXTRACTING MODE
1. A pile is extracted by merely tensioning the V-22 hammer hoisting
line. The amount of pull which can be exerted on the V-22 hammer
and extraction is limited by the rating of the suspension assembly and
the tensile strength of the pile.
CAUTION: DO NOT PULL IN EXCESS OF THE RATING OF THE V22
HAMMER'S SUSPENSION ASSEMBLY OR EXCESS STRESSES
WILL BE PUT ON THE SUSPENSION ASSEMBLY DAMAGING
ONE OR MORE PARTS. EXTREME CARE MUST BE TAKEN
DURING THE EXTRACTION PROCESS DUE TO THE HIGH LINE
PULL FORCE APPLIED BY THE PULLING CRANE. THE
REACTION DUE TO A SUDDEN LOSS OF LOAD MAY CAUSE THE
CRANE BOOM TO FALL BACKWARDS ACROSS THE CRANE
CAB. A SUDDEN LOSS OF LOAD COULD BE CAUSED BY A
PARTED CRANE LINE, UNEXPECTED LOSS OF CLAMPING
FORCE, OR SEPARATION OF THE PILE AT THE AREA HELD
WITHIN THE CLAMPING JAWS. ("BITTING THE TOP OUT OF
THE PILE")
CAUTION: A SECOND CRANE LINE SHOULD BE ATTACHED TO AN
ADJACENT PILE ("DEAD MAN") AND DRAWN TIGHT AS A
PRECAUTIONARY MEASURE AGAINST A SUDDEN LOSS OF
LOAD. CRANES USED FOR PILE EXTRACTION APPLICATIONS
SHOULD ALWAYS BE EQUIPPED WITH BOOM STOPS.
2. The ability of the V-22 hammer to switch instantly from driving to
extracting mode by merely pulling on its hoist line, has evolved a pile
driving procedure exclusive to vibratory usage. A hammer hanging on
the number one crane line is swung into the air. A sheet pile, for
example, is lifted from the ground on the number two crane line so
that the head of the pile is pulled between the clamp jaws of the
hammer. The jaws are then closed and the number two line is
slacked. Both hammer and pile are then held by the number one line.
The pile is stabbed in its location with the hammer. The hammer is
then turned on and the pile is worked into the ground. Usually out of
plumb at the outset, the pile is alternately driven and extracted until it
penetrates the soil sufficiently to be self-supporting. It is then pulled
far enough to be straightened plumb and quickly driven. (Sheet piles
are usually driven only a few feet and the adjacent pile is set.)
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