LOWER PLATE
H
~J
TYPE A-1
UPPER PLATE
TYPE A-2
LOWER AND
UPPER PLATE
TYPE A-3
FIGURE 8.3: ADDITIONAL CHAFE PLATES FOR TYPE A FAIRLEADS
Care must be taken when installing fairleads on sloping bulwarks, such as those in the bow area, lO
avoid Line chafing at the upper outboard edge of the frame. Type A-2 or A-3 of Fig. 8.3 would be
sui table for t hi s case.
Apart from line leads, (he following considerations apply when selecting universal fairleads:
- Roller diameter. A small diameter will reduce the strength of the line (refer to Section 6.2.4).
For use with wire rope with independent wire rope core, the roller diameter should be about
12 times the rope diameter. - Opening size (dimensions WI and W2 in Pig. 8.2). The ml.ntmum size is determined by the
space required to pass the eye of the line or end fittings {such as those requ ired for tails)
tlrrough the fairlead. The following minimum dimensions are recommended, provided that
the roller diameter is 12 times the diameter of the wire rope and four times the diameter of
a synthetic rope:
Width = 1.00)( roller diameter
Depth = 0.65 x roller diameter - Slrenglh. Strength should be the main crilerion. The recommended strength criteria is shown
in Table 4.3 of Section 4. Many existing designs do not com ply with these criteria. Oft en Ihe
frame is not strong enough to resist longitudinal forces such as those applied to spring lines.
Proper frame strength can be provided by fitting flat bar reinforcements to the outer edges
of the frame, as indicated by t.he letter 'K' in Fig. 8.2.
5-ROLLER TYPE - LEFT
5-ROLLER TYPE - RIGHT
6-ROLLER TYPE
FIGURE 8.4: UNIVERSAL FAIRLEADS WITH ADDITIONAL INBOARD ROLLERS