Harken XD control systems – Outhaul (with 16mm “Airblocks”)

Description

Harken XD control systems – Outhaul (with 16mm “Air” blocks)

This is essentially the equipment level originally introduced as the XD (Extra dimension) in 2001. They are by far the most widely used outhaul system proving to be efficient, reliable, robust, durable & cost effective. It remains the bench mark by which other systems are judged.

ILCAdirect has thus:

Retained the outhaul arrangement as originally supplied, because it has proved to be so effective.

Offers a choice of hook or shackle for the clew attachment.

Offers the XD outhaul in either:

1) Kit form – parts & lines only:
Comprising: 3 x Harken single 16mm “Air” blocks, 1 x Harken single with becket “Air” block, 1 x Clew hook or shackle, 1 x twisted shackle, 1 x Plastic hook (for shock cord retraction system), 1.Xm 3mm Dynema D12, 0.5 x 4mm Dynema D12, 6.0m 4mm Dinghy Control line, Shock cord (for retraction system), Tie lines.

2) Complete – parts list as above with “Prepared” lines:
Prepared primary line – Spliced Dynema D12. (Spliced primaries are the most effective securing method with eye sizes to allow the blocks to be “looped” on & off making for quick & easy line change.)
Prepared secondary line – Knotted 4mm Dinghy Control (DC) or 4mm Continuous Control (CC).(Knotted secondaries are the most effective securing method whilst also allowing for quick & easy line change.)

Note 1) ILCA4 – The ILCA4 sail has a shorter foot so a slightly different arrangement is required to accommodate this. There are a number of ways this can be achieved but  ILCAdirect recommends an additional strop is added to the sail. This means that when switching to & from the ILCA6 no change to the outhaul system is required.

Note 2) There are seemingly so many different lines from different manufacturers on the market utilising many different fibres each with  different advantage that the choice seems difficult. However a number of the different products are actually commercial names for the same thing & if the right questions are asked it simplifies the choice between the various advantages.

On the ILCA control lines are short & loads comparatively low so extension/stretch whilst important is of lesser importance than it might be on say a super yacht. Similarly chaff & heat resistance whilst important on a boat using winches is less important on an ILCA where the blocks & lines are often wet whilst carrying comparatively little load. However on an ILCA the blocks are comparatively small so line flexibility is more important.

Dynema is strong & flexible with little extension together with a low friction coefficient (i.e. its slippery). In its SK78 version it is moderately priced. That would seem to tick all our boxes for primary lines.
Therefore Dynema SK78 D12 – Single braid is used for primary lines.

Polyester is moderately strong, has good wear resistance, moderate heat resistance, has a moderate friction coefficient (i.e. is not slippery), is moderately priced & flexible. That would tick most of our boxes for secondary lines but mixing it with Dynema would seem to tick them all.
Therefore lines with a mixture of Dynema & Polyester are used for secondary lines.
Dinghy Control (DC) – Dynema core & polyester cover.
Continuous Control (CC) – Polypropylene core with a blended Dynema/polyester cover.

Note 3) Whilst many sailors use a laced handle on both the Outhaul & Cunningham/downhaul that seems to encourage tangling between the two systems. A better option would seem to be a simple loop on each. (The size of the loop being a further fine tune on the system.

Retraction system – Many sailors have problems with their retraction system. The ILCA direct system is simple, effective, reliable, cost effective & can be used in one of two ways. The ILCA class rules are permissive (i.e. the rules say what may be done)  & prior to 2018 attaching the shock cord to the travelling block was not permitted.

Method 1) The shock cord is lead from the cleat under the boom (& also under any control lines) though the clew of the sail & through the in line eye in the primary beside the traveling block with a knot in the shock cord keeping it in place. This has the advantage of directly pulling the travelling block back, maintaining it in the right attitude & keeping the secondary line taught. It also allows the cleat to be used to tension the shock cord as required whilst the spare tail is wound around the boom & hooked back on itself.
Method 2) In stronger winds it might be more difficult to rig Method 1) in which case undo the spare tail & hook the knot in the shock cord onto the hook.

For replacement primary line:

For replacement secondary line:

For replacement retraction system: