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| Operation |
| To set the Gear in
use: 1. Pull the appropriate snaffle line to feather the vane upright (or mid-way in its travel) with the high side of the vane pivot (or lead weight end) facing into the wind. 2. When the vane is upright engage the chain in its tiller clamp (or clutch pin in the wheel drum). 3. The vane should now be steering the yacht. 4. Most course alteration are made by simply pulling on the appropriate port or starboard snaffle line. The most important thing to remember is to keep the vane working approximately upright or mid-way and you must adjust the tiller clamp chain (or wheel drum clutch) against the main helm to achieve this. I feel this point is very obvious when using the gear and any further elaboration is unnecessary. 5. Disengagement of the tiller clamp or drum clutch enables instant manual steering and the servo rudder trails quite happily in the water without steering the yacht at all, even with the plywood vane blown over to full deflection. 6. If motoring for long periods it is a good idea to hinge the servo rudder up vertical out of the water (also when hove to). 7. Avoid extreme tension on the steering lines. Have them just tight enough to take out the slack. 8. Apply a good dose of oil to all moving parts (light engine oil but almost anything will do rather than nothing). 9. I would suggest oiling every 24 hours under continuous use. Pay special attention to the main rudder spindle (stainless tube) running vertically from the lower bevel gear through its casting down to the second servo rudder. |
| Performance |
| The Gear should steer the
yacht on all points of sailing (including downwind) to a standard
equal to a helmsman paying reasonable attention to his course.
Under normal cruising rig I fell my customers should never
have to steer by hand. The time when manual steering has
to be restored to is entering harbour, Flat calm/ motoring etc. The power developed by the servo rudder is proportional to the water speed and the gears control of the helm increases as the wind and water speeds rise. In a strong wind the pull on the steering lines is very high and it is impossible to prevent them moving by hand. In very light winds the vane and the servo rudder develop low forces which of course is all that is required under these conditions. |
| Design Comments |
| I feel the servo rudder design
such as the Aries (and other makes on the market) offers the
bets chance of achieving good self steering on all types and
sizes of yacht under virtually all conditions. The main rudder
of the yacht is remarkably efficient in that it only needs a
low human effort applied to the tiller or wheel to control a
vessel weighing perhaps 20 tons. I feel that any vane gear
system that does not operate on the main rudder but attempts
to steer the yacht directly ( direct acting type - helm lashed)
is tackling the problem in a very hard way. The servo rudder design requires more engineering in that the servo has to swing sideways and pull the steering lines with an appropriate framework to accommodate the rope pulleys, and the ropes have to be led forward to the tiller or wheel. However, this aspect is very easily dealt with and the rope and pulleys are basic yacht equipment that is very reliable and easy to replace. The basic design of the Aries was established in 1968 using a little theory, common sense and lots of experimentation and prototype building. Repeated attempts since have failed to offer any performance gain ( not even a trim tab on the servo rudder - but this was too complicated anyway). The gear does not rely on any high technology design or materials and could have been produced using timber , leather and lashings since the earliest recorded times ( if anyone wanted one). The design philosophy of the Aries is - " if it exists - the sea will smash it." No attempt has been made to calculate the stresses on the gear - it relies on brute strength and simplicity. |
| Specification |
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Aluminium castings grades AC5
(LM5) 33lb (15.08k). The weight of the mainframe overhanging the stern is 50lb (22.85 kilos). |
The mainframe structure is
of aluminium tubing and aluminium castings. The same tubing
is used for the deck tubes and servo rudder stock. It
is grade HT30, anodised and specially made in the hard drawn
as possible condition which makes the tube tremendously strong
(most aluminium tube is not as hard as this). The servo rudder is glass fibre with a foam core, with the rudder stock moulded in foam. The wind vane is 6mm marine ply - clear varnished (ply is much lighter than aluminium or plastics for this purpose and replacements are easily made on board). The servo rudder spindle (runs from the lower bevel to the rudder coupling) is a seamless tube, grade 316, polished. It runs in pure teflon bearings each 1" (25mm) long 11/2" (38mm) bore x 2" (50mm) O.D. |
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