2.3.2
Hoisting Ropes
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NOTE: For LANTNAVFACENGCOM, add bracketed paragraph
section.
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FS RR-W-410. Hoisting ropes shall be 6 by 37 class construction, improved
or extra improved plow steel, with an independent wire rope core.
Maximum
hoisting rope fleet angles shall be 4 degrees for drums and 4.75 degrees
for sheaves. Hoisting rope end connections, other than drum connections,
shall be speltered sockets with forged steel terminals.
Provide proof of
wire rope breaking strength. [Provide wire rope minimum safety factor of 5
to 1 based on the ratio of actual minimum wire rope breaking load to the
calculated load on rope when hoist is assumed loaded to rated capacity.
Certification from rope manufacturer verifying provided wire rope breaking
strength, shall be submitted to Contracting Officer and approved prior to
final acceptance of hoist. No paint or coatings will be allowed on the
wire rope. Minimum length of the wire rope shall enable the load hook to
operate through its full hook lift range and still have a minimum of two
full wraps of wire rope around the rope drum.]
2.3.3
Sheaves
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NOTE: Select 16 rope diameters for a class A or B
crane, and 18 rope diameters for a class C crane.
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Provide steel sheaves. Minimum pitch diameters shall be [16] [18] times
the rope diameter for running sheaves, and 12 times the rope diameter for
equalizer sheaves.
2.3.4
Drum
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NOTE: For LANTNAVFACENGCOM, add the bracketed
sentence.
**************************************************************************
**************************************************************************
NOTE: Select 16 rope diameters for a class A or B
crane, and 18 rope diameters for a class C crane.
**************************************************************************
The drum shall be of steel construction. Design drum so that not less than
two dead wraps of hoisting rope will remain on each anchorage when the hook
is in its extreme low position. Drum grooving shall be right and left
hand. Minimum drum groove depth, shall be 0.375 times the rope diameter.
Minimum drum groove pitch shall be either 1.14 times the rope diameter, or
the rope diameter plus 3 mm 1/8 inch, whichever is smaller. Minimum drum
pitch diameter shall be [16] [18] times the rope diameter. [The surface of
the drum which comes in contact with wire rope shall not be painted,
coated, or galvanized.]
2.3.5
Wheels
Trolley and bridge travel wheels shall be double flanged and of
rolled-to-shape wrought or forged steel. Wheels shall be rim toughened to
SECTION 14636N
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