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 TB 55-1900-232-10
There are two methods for correctly unreeling synthetic line. These are identical to the methods used for wire
rope and are discussed in Appendix B, Section B-6.1.
C-8 STOWING
Stow synthetic line away from strong sunlight, heat and strong chemicals, and cover it with tarpaulins. (Nylon is
also sensitive to fluorescent light.) If the line is iced over, thaw it carefully and drain it before stowing. If
feasible, store on appropriately treated wooden damage. Nylon is susceptible to a rapid reduction m strength
when exposed to rust. Ensure that it is not exposed to rust-prone bare steel surfaces.
C-9 INSPECTION
Regular inspection is essential to ensure that synthetic lines remain serviceable and safe.
It is also emphasized that no matter what has weakened the line, the effect of the same injury will be more
serious on the smaller sizes than on the larger sizes of line. Consideration should therefore be given to the
relationship of the surface area of the line to its cross section
Examinations of about one foot at a time may prove to be convenient. The line should be turned to reveal all
sides before continuing. At the same intervals, the rope should be untwisted slightly to allow examination
between the strands of three-strand and plaited rope.
Synthetic lines should be inspected after each use. Look for broken fibers m the outer layer and for
discoloration or appearances of melting. In examining between the strands look for these same evidences of
wear and, in addition, look for any appearance of a powdery substance between the strands. Broken outer
fibers may indicate that the line has been dragged over sharp or rough surfaces. Discoloration or melting may
indicate excessive frictional heat from either dynamic loads or from rubbing over smooth surfaces. Internal
wear, sometimes indicated as a fuzzed or fused condition between strands, may indicate fatigue damage from
repeated or cyclic loads and overloading. If after examination, there is any doubt about the safety of the line, it
should be discarded It is again emphasized that the effects of wear and mechanical damage are relatively
greater on smaller lines which, therefore, require more stringent standards of acceptance
The following section on types of wear should be helpful during the inspection of synthetic lines.
C-10 TYPES OF WEAR OR DAMAGE
The usual types of wear exhibited by synthetic lines are briefly discussed in the following notes.
a. General external wear. External wear due to dragging over rough surfaces causes surface chafing. In the
extreme, the strands become so worn that their outer faces are flattened and the outer yarns are severed In
ordinary use some disarrangement or breakage of the fibers on the outside of the line is unavoidable and
harmless if not extensive. Generally, nylon and polyester filament lines have a very good abrasion
b. Local abrasion. This abrasion, as distinct from general wear, may be caused by the passage of the line
over sharp edges while under tension and may cause serious loss of strength, especially if accompanied by
fused areas signifying high heat generated by rope surges under heavy load. Slight damage to the outer
fibers and an occasional torn yarn may be considered harmless but serious reduction in the cross-sectional
area of one strand or somewhat less serious damage to more than one strand should merit rejection When
such damage is noticed, protective measures should be taken. 'Typical protective steps are to smooth and
round off all rough or sharp areas on the surface which are chafing the line and apply chafing gear such as
rubber or plastic sleeves or cloth material secured by small stuff around the line.
C-4
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