Hull Mounted Gennaker Bowsprit 595-318-E Date 090401

Home , Bobstay, Bowsprit, Mast (sailing)

Standard Layout with full length launch tube

Through tube sheavebox supplied & fitted by OEM

Launch rope

Launch tube outer flange bush. Rubber retraction cord Fitted in place after the bowsprit is inserted into the launch tube Standard arrangement : A plain bowsprit with an external block at the outboard end.

Operation: The bowsprit is extended by a launch rope running from the inboard end collar, forward through a sheave box and then aft to the cockpit. As the bowsprit extends, the rubber retract cord stretches. When the launch rope is released, retraction is automatic. The rubber cord inboard end is attached to an eye on the aft launch tube plug. To adjust retract tension, the plug must be removed from the tube. It is held in place with self tapping screws.

Hull Requirement: Bowsprits are housed in an E-glass & vinylester tube bonded into the hull. The tube is supplied either overlength or cut to a custom length. The support structure must be strong, and placed as stated. The DBS (Distance Between Supports) dimension is critical, as this influences the bowsprit laminate design.

DBS Tapped ½” BSP (Distance Between Supports)

Drainage. The inboard launch tube end plug has a threaded water drain hole as standard. A drain tube can be fitted.

Launch Rope Arrangement The Launch rope must exit the launch tube just ahead of the bowsprit’s inner collar when in the fully extended position. The exit may be positiond around the launch tube to suit the internal layout. If fitted within ± 45° of the lower centre line, water in the launch tube will leak out. Optional Layout with retracting bobstay (waterstay) and full length launch tube

Bobstay (waterstay) fixed near waterline

Arrangement The bowsprit is fitted with a bobstay (waterstay) which is attached to the bow close to the waterline. This shares the vertical loading, and may reduce the required bowsprit diameter. The bobstay automatically retracts into the bowsprit when it is stowed.

Operation The bowsprit is extended by the launch rope. As the bowsprit moves forwards, the bobstay is pulled out to its limit The pole forward movement is stopped when the bobstay’s internal ball reaches the inner face of the outboard end. The position of the ball requires careful adjustment to ensure that the bobstay is tight when the bowsprit is fully extended.

Alternative Layout with short launch tube in bow well The bowsprit retracts into the self draining bow well or deck trough. Extension is by a launch rope which may be connected directly to the bowsprit inboard end (1:1) or routed through two sheave boxes and attached inside the bow well (2:1). When the launch rope is released, retraction is automatic.

Launch rope

DBS Self draining bow well (Distance between supports) Launch Tube. The tube is made from Epoxy-glass. It is usually supplied cut to length, to suit the bowsprit arrangement.

Bowsprit Size Launch Tube Flange Bush

GC076 ø108 ø109 Launch Flange G088, GC089 ø121 ø121 Tube ø bush ø GC100, GC101 ø131 ø130 GC120 ø156 ø158 GC137 ø171 ø175

The outer flange bush is usually supplied with the bowsprit. It is attached to the launch tube with self tapping screws. When fitting the bowsprit, temporarily remove the inner sleeve and flange bush. Slide the flange bush into the launch tube and fit the screws. Then remove the screws and refit the flange bush and inner sleeve to the bowsprit. Tie a messenger line to the rubber retract cord, and lead it to the inner lube end plug. Fit the launch rope, slide the bowsprit halfway into place. Using a hook, catch the launch rope and lead it through the exit box. Continue to slide the bowsprit into the launch tube, and refit the flange bush screws. If a retractable bobstay is fitted, adjust the knot position now. Hold the messenger line, and carefully extend the bowsprit to its operating position. Pull the bobstay out and attach the shackle to its position near the waterline. Remove any slack, and mark the bobstay where it enters the outboard end. Retract the bowsprit, remove the shackle and attach a messenger line to the loop. Pull the bobstay back into the bowsprit until the ball and knot can be reached at the inboard end. Adjust the knot position, and pull the bobstay out. Readjust the knot until the mark is correctly positioned at the outboard end. Adjust the bobstay retract rubber cord. Finally tension the main bowsprit rubber retract cord.

Standard arrangement Launch rope

Messenger line