Jib Sheeting Trial

23 January 2019

 

TANSW gets approval for improved jib sheeting trial.

 

Following a presentation by Brad Stephens to the Measurers meeting held at Largs Bay Sailing the ATC have given approval to TANSW to conduct a trial of an improved jib sheeting system for the Tasar.  Initial trials will be conducted at Balmoral Sailing Club using the Club Tasar with TANSW reporting to the ATC on a regular basis.  Once Brad and the team have worked through the initial program the boat with the modified system will be made available to sailors to test and offer feedback.

 

The following outlines the rationale for the proposed system.

 

Changing the Jib Sheeting System on the Tasar.

 

If there was an off the shelf replacement part for the jib fairlead/cleat on the Tasar that offered the handling advantages of a ratchet block it would already have happened and Tasar crews would have benefited from the same improvements that have seen ratchet blocks replace the simple blocks for the mainsheet and traveler.  That there is no off the shelf replacement part has always made improving the jib sheeting system on the Tasar problematic. 

 

• Adult female crews are generally strong enough to pull the jib sheet on as hard as necessary but controlled release in strong or gusty conditions can be problematic and active trimming (as helms do with ratchet blocks on travelers) represents some difficulty for the typical female crew of average to good strength.

 

• Any modified sheeting system must protect the geometry of the existing fairlead with respect to sheeting angles (vertical and athwartship) although practically there was a minor change moving from the original Ronstan fairlead to the Holt-Allen, now Allen system.

 

• A 2:1 purchase system can be (and has been) used from the standard fairlead position although it creates some handling issues with additional sheet length to take-up and keep clean (no tangles). A 2:1 adds mechanical advantage which fix's the issue in 1) with respect to controlled release of the sheet but adds complexity and is not a universal solution for all.

 

• Adding a ratchet block at the fairlead position ( assuming current sheeting geometry is retained ) is unlikely to create enough wrap around the ratchet block to provide good holding power.

 

• Boats that were similarly rigged to the Tasar in 1975 such as the NS14 have all moved to turning blocks (ratchet) and deck mounted cleats and other similar sized boats (470 & Fireball) have been able to introduce ratchet blocks into their jib sheeting systems.

 

• Practically, the solution to an improved jib sheeting system for the Tasar, that is of universal benefit, is to mount a ratchet block (cheek block) and cleat on the side deck at the outboard end of the track and change the track/fairlead to a style that will protect the sheeting geometry. The attached jpg shows the proposed layout. Note, a ratchet block allows for a controlled release and active trim through its holding power, but it does not provide mechanical advantage, which is considered unnecessary (see point 1.).