to the stern of a boat
ensures both a strong
and elegant installation,
part of the gear
remaining hidden inside.
It also allows to
lead control lines internally to blocks
on boat's steering quadrant,
then to jamming cleats in cockpit
for instant connect,
disconnect or trim.
Additional bonus :
when wind is unstable or inexistant,
a small tiller pilot
located inside the lazarette
drives the servo-pendulum
which still provides power
to move the rudder,
feeding on mere milliamps.
easier than it looks
- even afloat
and other hardware
needed to lead lines to boat's
are not, being different in type on
A hole saw held perfectly horizontal
and parallel to keel cleanly cuts
hole for support tube.
Glass laminate (or weld)
aft end of tube to hull.
Forward end of mounting tube
supported by two struts
(supplied with appropriate fittings)
at an angle between 90° and 120°,
to reach either underside of deck
or pads bonded to hull.
on stern platform.
Tube welded to steel hull.
Aluminium tube offered
for welding to aluminum hull.
to transom angle,
two halves bolted together,
both sides of transom.
Second pair of struts
if mounting tube extends
some distance past transom
Outboard rudder or boarding ladder?,
Only measurable effect of offset
felt if boom extends far aft, close to vane : boat could not sail
as close to wind when vane on leeward
side, wind received by vane being deflected by leech of sail
directly to windward ; other tack, or as soon as sheets are
eased, problem disappears.
Reduced paddle area when heeled has no effect because when
there is heel, there is most often speed. The force
generated by the paddle being proportional to the
square of speed through water, the paddle generates much more
power than is needed; paddle area is critical only at
low speed, which produces little heel.
All struts and braces adjustable.
Slip horizontal axle through tube.
Fasten quadrant to forward end,
wind vane tower aft.
Diagonal braces to deck
Control lines led through blocks
fastened to quadrant or disk
or short auxiliary tiller
(such as the tiller of a hydraulic system).
To ensure ideal 2:1 ratio
between CH quadrant tilt
and rudder angle
(for 10° tilt, 5° rudder),
from rudder axis
equal to CH quadrant radius.
From there, lines
to jamming cleats in cockpit.
for instant connect, disconnect or trim.
and adjusted for weather or lee helm
by pulling lines tight
and cleating them.
instantly disconnects vane
for hand steering.
Click here to see various
Internal connection impractical?
Control lines turn wheel
by going around stops
placed on wheel spokes
from wheel hub
ensuring 2:1 ratio
between quadrant tilt
on wooden wheel.
led through fairleads on tiller
located at a distance
the radius of CH quadrant
then forward to jamming cleats.
is inside and tiller outside,
Control lines are led out
through holes in sides or back of cockpit;
No room inside lazarette
for windvane quadrant ?
A tube extends
above horizontal axle,
to work as control arm.
On a boat with outboard rudder,
to back of rudder head
led to blocks on rudder head.
Since there are no lines to it,
tiller can be lifted to vertical
while CapeHorn is steering,
free of obstruction.
connected to back of rudder
through rigid control arm
To allow use of davits on boat with step stern,
windvane tower at forward end of horizontal axle
passing through the deck.
If your boat
presents a specific problem, send us photos showing its
stern and steering gear belowdecks.
We are not
without imagination and may suggest an original
for boats below 35'-40'
Spray ; for larger boats
Overall length of yacht
is only a rough guide
in the choice between
The main criterion is in fact the size of its rudder
and the amount of effort required to move it.
A 40 ft. plus
boat that is well balanced and easily steered, could
still use the smaller Jean-du-Sud model (provided
its freeboard is not too high). On the other hand, a
boat that is not so well balanced and that is hard to
steer, would need the larger and more powerful
Spray or Joshua, even if it is
shorter than 40 ft.
Determining factor in the choice
is the rudder dimensions (total area, type, aspect
ratio), combined with height of horizontal axis above
the waterline. Sail balance should be also taken into
Mounting tube (OD)
JdS 2.5" (62 mm), Spr
3.5" (89 mm)
Stock of steering oar JdS 1" (25
1.25" (32 mm)
Width of paddle
JdS 5" (127 mm)
Spr 6" (152 mm)
Paddle length proportional to boat's rudder
How to measure
custom-build a CapeHorn
four dimensions needed:
-LMT (Length of Mounting Tube)
-HWT (Height of Windvane Tower)
-HWL (Height of horizontal axle above WaterLine)
-Average height and width of rudder
Length of Mounting Tube (LMT)
Horizontal axle links outboard steering oar
to inboard quadrant
pivoting inside tube passing through hull
called Mounting Tube.
Its length (LMT) is measured
between aft face of CapeHorn quadrant
to aftermost part of hull
or any of its appendages
that could be in way of steering oar..
Aft end of the mounting
tube should also clear
trailing edge of rudder
if it extends past hull.
To measure LMT,
the optimum position of CapeHorn quadrant
in lazarette or cockpit.
Dimensions of Quadrant
-JdS : 8" (205mm) 1" (25 mm) thick
-Spray :11" (280 mm ) 1.25" (32 mm) thick
quadrant movement, circular space (CS)
needed at forward end of tube :
- 16" (410mm) diameter for JdS
- 22" (560mm) for Spray
If space (inside lazarette
or in cockpit) is limited to one half-circle below
or above the horizontal axis, gear will work just as
well, but possibility of flipping pendulum up
for storage along windvane tower is lost.
only a few inches short, a smaller quadrant is supplied.
Performance is not affected and ideal 2 : 1
ratio between quadrant tilt and rudder angle is
retained if blocks on steering quadrant (or aux.
tiller) are placed at a distance (from rudder axis) equal
to CapeHorn quadrant radius. Only load on control lines and blocks is increased.
Quadrant inside lazarette,
Ideal position arrived at
by taking into account
both space required for quadrant itself,
and lead of control lines.
Quadrant mounted indifferently above or below
In many lazarette installations, top of quadrant
reaches a few inches below deck
and turning blocks can be bolted under it.
and aft cockpit bulkhead,
(often under helmsman's seat)...
...ensures both simple and
both ends of tube
supported by a bulkhead.
Leave room for
to co-axial control mechanism
in front of quadrant.
only controls steering oar, smallest tiller-type
unit steers regardless of boat size, feeding on mere
If space is limited, autopilot can be located
elsewhere and connected to control arm through
blocks and light lines (with bungee pulling the other way).
Height above Waterline (HWL)
If U-shaped metal plate
linking steering oar to its stock
is kept above water,
drag kept to minimum.
Plate extends below
13" for JdS
This height is considered a
of horizontal axle
above waterline and dimensions of yacht's rudder
ensures steering oar provides adequate power
to move rudder in
with minimum drag.
Standard Height of Windvane Tower (HWT)
(above horizontal axle)
-JdS: 53" (135 cm)
-Spray:65" (165 cm)
In most cases
in clean air.
to reach over
to duck under
vane kept below,
Light air vane
24" (60 cm)
above top of tower,
heavy weather vane,
17" (432 mm)
See a complete installation of a Spray on a Valiant 40
Suite : Outboard Models