11
2.5 Calculating the length of the forestay wire.
(The following is valid for a yacht with the mast stepped.)
1. Slacken the backstay as much as possible, but make sure that any rigging screw is not unscrewed so far
that the threads are no longer visible ”on the inside”. The forestay setting should not be adjusted. If there is
insufficient adjustment in the backstay, and the forestay rigging screw must be adjusted to allow removal,
first mark its thread with adhesive tape.
2. Pull the masthead forward using the genoa halyard. Secure the halyard using a ”D” shackle or tie it to a
strong deck fitting. For safety reasons, do not use the halyard snap shackle. Secure the opposite end of the
halyard properly.
3. Go up the mast. Connect a free halyard to the forestay. Then detach the forestay and lower it using the free
halyard. Bring the stay down and place it on a flat surface. If the forestay rigging screw was slackened,
adjust it back to the tape mark
4. Measure the forestay length (FL) with just enough tension to keep the forestay straight on the ground
Forestay length (FL) is the distance between the hole in the swaged top terminal and the hole in whatever
lower part that was attached directly to the hole in the chain plate. Enter the measurement into ”Table 2”
below, in the row marked FL
If a Sta-lok terminal (with or without rigging screw) is included, the wire is supplied over-length. The wire has
a swaged eye terminal on one end while the other end is open (= without terminal). If your Furlex is supplied
with a fixed-length forestay, with a swaged eye on one end and a swaged stud in the other end, skip this part
and go directly to 2.6. The same apply for rod stays.
If a stud-terminated stay is to be manufactured by a local rigger it is important to note that WL in this case
equals the length of the finished stay, from eye to end of stud, see page 13. WL is calculated in table 1.
Before assembly, an over-length wire (for Sta-lok) must be marked and finally cut to the correct length to fit
the boat’s actual forestay length. To find out the correct measurement, follow the steps below. If the mast is not
stepped, you can jump directly to step 4 stepped, you can jump directly to step 4.
Table 2. Calculation of forestay wire length
Your
forestay
Example
304TD 10mm
with rigging screw 50%
extended
FL
Existing forestay length including rigging screw, no tension.
16070
CH
Add the distance between the hole in the chainplate and deck level, along the
direction of the forestay.
40
FLD
FLD=FL+CH
16110
TDH
Deduction for the level of Furlex TD above deck. 204TD: 125mm
304TD: 145mm
145
NFL
New forestay length NFL=FLD-TDH
16110-145=15965
T
Deduction for wire t toggle:
150
WL
Cutting measurement.. WL=NFL-T
The new forestay wire is to be marked at this point
(For forestays with swaged stud, WL equals the length of the finished stay
from the upper eye terminal to end of stud. See fig 2.6.1 page 13.
15965-150=15815
WIRE
Without rigging screw:
With rigging screw 50% extended:
204TD
Ø6 mm wire:
Ø7 mm wire:
Ø8 mm wire:
40 mm
Ø6 mmwire: 125 mm
Ø7 mmwire: 125 mm
Ø8 mmwire: 120 mm
304TD
Ø 8 mm wire:
Ø10 mm wire:
45 mm
Ø 8 mm wire:
Ø10 mm wire:
150mm
ROD
Without rigging screw:
With rigging screw 50% extended:
204TD
Rod -8
Rod -10
Rod -12
Rod -15
40 mm
Rod -8
Rod -10
125 mm
Rod -12
Rod -15
120 mm
304TD
Rod -15:
Rod -17:
Rod -22:
45 mm
Rod -15:
Rod -17:
Rod -22:
150 mm
