The Drop Keel and Rudder
Page updated 6 April 2009
The Keel Plate
The steel keel plate that forms the lifting part of the keel on the SeaHawk is "L-shaped" and supported at the two extremities. At the forward end a substantial bolt acts as a pivot so that the keel can be retracted into the ballasted moulding in the hull. At the aft end it is supported on a steel strop. When raised the tip of the keel rises through the cabin threshold. The keel can then be secured in the raised position with a short rod passed through a hole in the tip of the keel.
The Pivot Bolt
One reads reports about some boats where the hinge pin on keels has failed. No one has yet reported such a problem with a SeaHawk. Below are pictures of of a typical keel bolt, in situ. The first, viewed from starboard, shows the nut and washer. The second, from port, shows the bolt head. Both pictures showing the substantial plates through which the bolt passes that reinforce and prevent wear to the pivot.
The Keel Strop
The strop is a simple length of multi-strand steel cable one end of which is attached to the tip of the keel plate. At the other end there are two basic designs of handle. The design used does not appear to relate to the age of the boat, suggesting that it depended on what was in stock when the boat was built rather than a conscious design change decision.
The Aluminium Keel Handle
The first type of handle is of cast aluminium and locates in a matching socket mounted on the cabin threshold step. The length of strop with this type of handle has been measured on several boats at 14". With this type, each end of the cable is spliced into a loop. These are then held in place by a simple countersunk bolt passing through a slot in tip of the keel and the handle. The pictures below show the detail of the aluminium handle
The Alternate Keel Handle
The second design, with examples varying slightly, is cruder. A threshold plate, rather than a purpose made socket, includes a narrow slot to the rear of the main aperture. When the keel is lifted, the cable pulled backwards and the ferrule immediately under the handle is used as a stop within the narrow slot preventing the keel dropping again. The example below, on the left, is a was faithfully copied, including the builders mark, when the owner restored his boat.
The length of strop with this type of handle has been measured on several boats at 16".
Rudder
The standard rudder hangs on pintles on the transom. It is not designed to lift as the fixed part of the keel draws more than the rudder, so the keel will always touch the bottom first, unless the boat is being launched from a heavily sloping lee shore.
Essentially, it is made of three planks of one inch thick mahogany, although the central one is "split" into two parts creating a socket near to the top through which the tiller is passed. The tiller is then secured by a pin dropped through a hole as it protrudes all the way through the head of the ruder.
(The rudder shown here shows signs of a repair as, when new there should not be the bolts that can be seen in line with the lower gudgeon. Damage to the rudder blade through contact with an outboard propeller is also common.)