Harken 477 Small Boat underdeck furling User Manual
Page 4
4
477, 478, 493 Small Boat Underdeck Furler
Hole Saw Size – Refer to information below and choose hole saw for deck plate.
Deck Plate Ball Ø
Recommended Hole Saw Ø
A
B
Requires Some Beveling
Requires No Beveling
Unit
in
mm
in
mm
in
mm
in
mm
477
2.6
66
2.7
68.5
2.5 or smaller*
65 or smaller*
2.75
70
493
3
76
3.25
83
3 or smaller*
75 or smaller*
3.25
85
478
4.25
108
4.5
114
4.25 or smaller*
110 or smaller*
4.5
115
* A smaller hole than listed may be used to fashion a socket in the deck to conform to the ball shape. This can improve the
appearance and reduce the amount of sealant required. See drilling template in Appendix.
Planning Installation
Hoistable Halyard Swivel
Tools/Parts You Will Need
A
B
C
An optional hoistable ball bearing halyard swivel can be installed
on your headstay so you can raise or lower the sail without removing
the headstay. Hoistable halyard swivels are independent of the head-
stay, allowing you to tension the luff separately from the mast rake.
Hoistable swivels work along with your standard Harken Small
Boat furler.
IMPORTANT! Hoistable halyard swivel must be loaded on stay before
terminals are made. Make sure the end with circlip is facing up.
When using Hoistable Halyard Swivel adapter tangs provide
a “Y” attachment to connect both stay and sail tack to the
lower unit. A Sailmaker Eye may also be used. The eye
consists of a swage marine eye with a hole designed
for lashing or shackling the tack to the terminal.
Hoistable swivel
Upper swivel
Halyard
Furl
Unfurl
1. Hole saw
5. Deck sealant
2. Center punch
6. File for beveling
3. Scissors
7. Wrench for deck plate bolts
4. Rigging or black tape
8. Power drill/drill bit for pilot holes
3
4
2
1
5
7
6
8
Fasteners for Mounting Unit to Deck (Not Supplied)
Unit
Fastener Ø
C–Deck Plate Thickness*
477
5 mm
1
/
4
" (6 mm)
493
5 mm
1
/
4
" (6 mm)
478
6 mm
3
/
8
" (10 mm)
*Add deck thickness to this measurement
or
Sailmaker Eye
Adapter Tang
Sail Tack
Securing Points
End of halyard
swivel with
circlip faces up
Circlip