Integrated into the boat
and built to measure

Integrated into the stern of the boat, the CapeHorn Self-Steering System becomes virtually as strong as the boat itself.

A tube (called the Mounting Tube) is fibreglassed strongly to the transom; its forward end held by struts fastened up to the underside of the deck or down to pads glassed to the hull. Inside this tube, a smaller tube is allowed to pivot, linking the servo-pendulum trailing behind the boat, to a quadrant inside the lazarette.

(If this installation mode is not possible or desirable, a conventional installation mode, totally outboard, is possible. See: Outboard Models)

 

Contrary to all others, each CapeHorn unit is built to measure :

- the length of the mounting tube is made to measure  to use minimum space inside; 
- the windvane tower can be made taller to reach over a bimini or a dodger, or shorter to duck under a mizzen boom;
- the size of the servo-pendulum is proportional to the boat's rudder.

 

The CapeHorn can be integrated
into all types of sterns

 

Classic

 

Reverse

 

Canoe

 

               Open Cockpit or  Scoop

 

Jean-du-Sud or Spray?

Jean-du-Sud; for boats below 40'

Spray; for larger boats

The overall length of the yacht is only a rough guide in the choice between the lighter Jean-du-Sud or heavier Spray models. The main criterion is in fact the amount of effort required to turn the rudder.

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.

The determining factor in the choice between the two integrated models is the rudder dimensions (total area, type, aspect ratio), combined with the height of the horizontal axis above the waterline. The sail balance should be also taken into account. It is better in the final analysis to seek our opinion before making the final decision.


How to Integrate a Jean-du-Sud or Spray to Your Yacht

Each CapeHorn Integrated Self-Steering is custom built. In order to provide a perfect integration between a Spray or Jean-du-Sud (JdS) and your yacht, the ideal dimensions of its three main segments must be determined.  The length of the horizontal axis and mounting tube (LMT), the height of the windvane tower (HWT) are dependant on the specific shape of the boat's stern section. The length of the servo-pendulum is determined by the height of the horizontal axis above the waterline (HWL) and the rudder dimensions.

 

Length of Mounting Tube (LMT)

The horizontal axis that links the outboard steering oar to the inboard quadrant pivots inside a tube fastened to the hull, called the mounting tube. Its length (LMT) is measured from the aft face of the quadrant to the aftermost part of the hull or any of its appendages that could be in the way of the steering oar.. The aft end of the mounting tube should also clear the trailing edge of the rudder if it extends aft of the hull.

In order to determine LMT, one must first determine the optimum position of the CapeHorn quadrant inside the boat. This quadrant can be placed either in the lazarette or in the cockpit.

 

Dimensions of the Quadrant

Quadrant radius is 8" (205mm) for JdS and 11" (280 mm ) for Spray (if space is limited, an 8" quadrant can be supplied with a Spray.) For 360° quadrant movement, forward of the tube, a circular space ("CS") diameter of: 16" (410mm) for JdS and 22" (560mm) for Spray. JdS quadrant is 1" (25mm) thick, Spr quadrant is 1.25" (32mm). If space (inside the lazarette or in the cockpit) is limited to one half-circle below or above the horizontal axis, the gear will work just as well, but the possibility of swinging the pendulum up for storage along the windvane tower is lost.

 

Quadrant in Lazarette

If the quadrant is placed inside the lazarette, its ideal position is arrived at by taking into account both the space required for the quadrant itself, and the lead of the control lines. The quadrant can be mounted indifferently above or below the horizontal axis. In many lazarette installations, the top of the quadrant reaches a few inches below the underside of the deck and the turning blocks can be bolted to the underside of the deck.►►

 

Quadrant in Cockpit

The mounting tube can be made to go through both the transom and the aft cockpit bulkhead. This puts the quadrant inside the cockpit, against the bulkhead, often under a helmsman's seat. This provides an installation that is both simple to perform, and structurally strong.◄►

 


 Space for Autopilot

Since the autopilot only controls the steering oar, the smallest tiller-type units can be used, even on a large boat.

If space is limited, the autopilot can also be mounted elsewhere and connected to CapeHorn control arm through light control lines.

 

Height above Waterline (HWL)

If the U-shaped metal plate linking the teak steering oar to its stock is kept above the water, drag is kept to a minimum. This fitting extends 16" for JdS and 21" for Spray. below the horizontal axis and this height is considered as a minimum. If it is higher, the length of steering oar is increased accordingly.

Knowing the height of the horizontal axis above the (dynamic) waterline, and also the dimensions of the yacht's rudder, allows to optimize the length of the steering oar and make sure the CapeHorn provides adequate power to steer any size yacht.

 

Height of the Windvane Tower (HWT)

Standard height of the top of the windvane tower above horizontal axis is 53" (135 cm) for JdS and 65" (165 cm) for Spray. In most cases, this places the windvane in clear air above the stern pulpit. This dimension can be increased to reach over a pilothouse or bimini,

or reduced to duck under a mizzen boom.
 



The light air windvane reaches24"(60 cm) abovethe top of the tower,and the heavy weather
vane, 17" (432 mm)
(all models). (H)

 

 

Metal hulls

The mounting tube can be welded to a steel hull. An aluminium mounting tube can be supplied for welding to an aluminium hull.

When welding is impractical, a Delrin collar is used to bond the mounting tube.

 The collar adapter is cut to the angle of the transom, the mounting tube is bedded through it and the two halves are bolted together, on either side of the transom.

 

Forward End of Mounting Tube

The forward end of the mounting tube is held in place by two struts (supplied with appropriate fittings) bolted at an angle between 90° and 120° on the tube, and cut to reach either the underside of the deck above, or a pad glassed to the hull below. A reasonable distance between the tube support at the transom and the struts forward ensures a strong installation.

 

Open Cockpit or Stern Platform

Instead of being inside, the struts can be placed outside on boats with stern platform.

 

Second Pair of Struts

A second pair of struts (extra) can be provided to ensure adequate strength if the mounting tube extends some distance past the transom.

 

 

 

Special Models

 

If there is no room inside the lazarette for the windvane quadrant but an integrated installation is still desired, (to allow control of the servo-pendulum by a small autopilot), it is possible to replace the quadrant by extending the tube housing the servo-pendulum stock above the horizontal axle so that it works as a control arm.▼►

 

 

 

 

I

Windvane Tower Forward

On boats with step stern, or to allow the use of davits, it is possible to locate the windvane tower at the forward end of the horizontal axle instead of its aft end.

▼▼▼

 

 

 

 

 

 

 

 

If your boat presents a specific problem, ask us : we are not without imagination and may suggest a solution to your specific problem

 

 

 

 

 

How to measure
to integrate a CapeHorn into a boat

 

In order to build a CapeHorn to the ideal dimensions for a given boat, we need four dimensions :

LMT (Length of the Mounting Tube)

HWT (Height of Windvane Tower)

HWL (Height – of horizontal axle – above WaterLine)

Boat’s rudder average height and width

 

LMT

Before you measure, you need to determine the exact location of the CapeHorn quadrant.  The dimensions of the  quadrant are :
                - 11”, 1 ¼” thick – 280 mm, 32 mm - for Spray
;
                - 8”, 1” thick – 203 mm, 25 mm - for JdS).
The quadrant needs to be allowed to pivot through 360 degrees. Cutting a cardboard disk 
                -  22 in - 560 mm . dia. for Spr
               
- 16" 460 mm for JdS
makes it easier to materialize the space needed for the quadrant.

In locating the quadrant, you need to take into consideration the lead of the control lines and the location of the first pair of turning blocks, which need to be in line with the groove in the quadrant.

Once the location of the CapeHorn quadrant is determined with precision, you can start measuring, using a plumb bob.  Since one end of the mounting tube is inside and the other end outside, you will need a baseline which is accessible both from the inside and outside by dropping your plumb bob through an opening in the deck (the hole for the emergency tiller is often convenient).

1 : Measure inside (horizontally and parallel to the fore and aft line) from the aft face of the quadrant to the baseline (plumb bob)

2 : Measure outside from the aftermost point of the hull (or its appendages) to the plumb bob.

3 : The sum  (or difference if the baseline is located forward of the quadrant)  between those two dimensions is your LMT.  Measure again, to make sure.

HWT

Ideally, the windvane tower should be tall enough to allow the vane to receive an undisturbed wind.  If the boat has a dodger or a bimini, the tower can reach that level.  Measure vertically from the level of the horizontal axle to where you want the base of the vane to be.  (The light air vane itself extends 24 inches – 610 mm above the top of the tower, and the heavy weather vane, 17” – 432 mm for all models).

Ketch or Yawl
   If the boat is ketch or yawl rigged and the mizzen boom extends much past the rail, the tower is made short enough to allow the vane to work under the boom.  However, if this does not allow the vane to receive a clear wind, all is not lost.  The tower is made tall enough to clear the rail; the consequences in that case is that when you tack or jibe, the mizzen boom will tilt the vane out of its way, and the wind and counterweights will bring it back up.  Of course, performance when hard on the wind will be affected, as the mizzen may deflect the wind received by the vane.  But as soon as the sheets are eased and the wind moves towards the beam, this problem disappears.  (Hard on the wind, most ketches or yawls steer themselves anyway or do not use their mizzen.) Alternately, the horizontal axle can be made longer to allow the vane to clear the end of the boom; the only consequence is to make the boat longer and the vane harder to reach.

 HWL

Measure from the level of the horizontal axle down to the waterline.  This dimension, combined with the average height and width of the boat’s rudder, allows to make a servo-pendulum proportional to the boat’s rudder area so that it provides adequate power to steer each boat.

 

 

Installation of the CapeHorn Integrated Self-Steering system
is easier than it looks - even afloat.


All necessary fittings are supplied.

 

A hole saw is used to cleanly cut an opening for the support tube.  Glass laminate (or weld) the aft end of the support tube to the hull. On metal hulls (when welding is impractical), the support tube is run through a Delrin collar. The collar is sliced to match the transom rake and the two halves are then thru-bolted together.
 

 Fasten the forward end of the support tube with struts running up to the deck or down to the hull. All struts and braces are fully adjustable.  Slip the horizontal axis through the support tube. Connect the quadrant to the fore and the wind vane tower to the aft end. Braces are run from the tower to the deck for support.
 

To avoid cutting a chainplate gusset or to share the transom with a boarding ladder, the CapeHorn can be mounted off-centre. Top performance is maintained even when the unit is offset far enough to allow a transom mounted rudder to swing.

The only measurable effect of an offset installation would be felt on a boat with a long boom, extending far aft, close to the vane : the boat could not sail as close to the wind on the tack which places the vane on the lee side. because the wind that reaches the vane would have been deflected by the sail; on the other tack, or as soon as sheets are eased, the problem would disappear.
    The reduced paddle area when heeled has no effect because when there is heel, there is most often speed and the force generated by a paddle is proportional to the square of speed through water and the paddle generates much more power than is needed; paddle area is critical only at low speeds, which produce little heel.
 

 Connecting the Control Lines:

The control lines can be connected directly to the yacht’s steering system, while retaining the possibility to connect, disconnect or trim from the steering position, without going below. This greatly reduces cockpit clutter.

 

The lines are led through blocks fastened to the quadrant or to a short auxiliary tiller (such as the tiller of a hydraulic system) and then back to fairleads placed close to the last turning block. From there, they are led to jamming cleats placed within reach of the wheel.

 

The vane is connected by putting the lines in tension and cleating them. It is adjusted for weather or lee helm by pulling one line shorter than the other. Releasing the lines from the jamming cleats instantly disconnects the vane and allows manual takeover►►►

 

Click here to see various connections

 

Wheel steering

If a direct connection to the quadrant is impossible, The control lines turn the steering wheel by going around stops placed on the wheel spokes, then to jamming cleats. These stops can be placed closer or farther from the hub, so the ideal ratio of 2:1 between rudder angle and quadrant tilt can be easily arrived at.

A teak drum can be supplied for wheels made of teak.

 

 

 

 

 

 

Tiller Steering

The control lines coming from the CapeHorn quadrant (or control arm) are led through turning blocks on either side to the tiller. The control lines are usually led out through holes drilled in the sides or back of the cockpit; then (through additional blocks if needed) through fairleads on the tiller, and forward to jamming cleats. The distance between fairleads and rudder axis is usually  twice the radius of the quadrant or control arm (2:1 ratio).

See a complete installation of a Spray on a Valiant 40

Suite : Outboard Models

CapeHorn Integrated Self-Steering

An image is worth a thousand words
and sending it by E-Mail is so easy :
send us pictures of the stern of your boat,
the cockpit and lazarette area,
its steering gear,belowdecks if needed.

We will suggest a model and its installation,
and tell you what and where to measure
to build a gear that will fit your boat perfectly.

E-Mail

Withness how some of our customers have, on their blog or website,  described their installation and use of the CapeHorn

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