Overview

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This section of the Maintenance Guide gives a full description of the Xenon Dinghy Jib system. It provides the specification of many of the components and describes how the components are linked and how they operate. It is intended to be useful to anyone replacing  / repairing or renovating the Xenon Jib System.

Apart from the essential function of supporting the mast when sailing, the Xenon Jib System plays two important roles; the Jib Sail provides a significant improvement in the efficiency of the main sail and manoeuvrability of the dinghy and, just as importantly, the flexibility of the Jib System enables a suitable mast rake and rig tension to be selected for the prevailing wind and water conditions. The Jib tension cannot (should not) be adjusted whilst afloat.

The Jib System has 5 main components;

1.  Jib Wire (runs up the Luff of the Jib Sail)
2. Wire Jib Halyard (inside the mast, used to tension the Jib wire)
3. Soft Rope Tail (necessary to rig and derig the Jib sail)
4. Jib tension system (applies tension to the Jib wire and mast shrouds)
5. Jib Furling system consisting of the Furling drum and Top Swivel

The Forestay is not part of the Jib System but is used to replace the Jib System whenever the Jib is derigged, eg supporting the mast when In the boat park.

Description of Component links
The Jib System starts with the Furling drum fastened by two heavy machine screws into the bow of the dinghy. The Tack (lower) end of the Jib wire is fitted with a ‘hard eye’ and is connected to the top of the Furling drum with a ‘D’ shackle and clevis pin. See photos below.

The ferrule needs secure taping to avoid any possibility of snagging damage to the Gennaker sail. The retaining strap prevents the Jib sail from riding up the Jib wire.

           Tack (lower) end of Jib wire fully taped                                                    Tack end of Jib wire – note essential Sail retaining strap

The Head of the jib wire is also fitted with a ‘hard eye’ and this is connected via a Bow shackle to the lower fork of the Top Swivel. The upper fork of the Top Swivel connects to the ‘hard eye’ in Jib halyard wire. The Head of the Jib sail also has a retaining strap to prevent the Jib sail from sliding down the Jib wire. The webbing strap is clearly visible in the photo below left. If you are proposing to replace the Jib wire make sure the new ‘hard eye’ can be fed down the Luff past the Jib sail Tack cringle. The Jib halyard wire / Jib wire connection is shown in the middle photo and is taped when in service. The static portion of the Top Swivel and the clevis pin and ring are shown fully taped – again to avoid potential damage to the Gennaker sail.

The end of the halyard wire then disappears into the Jib Box over the 35mm sheave (photo above right) and travels down inside the mast section and emerges as a long 'soft loop' at the back of the mast, ie there is no stainless steel thimble or ‘hard eye’.  (Photo above right). The halyard wire has a long soft rope tail, spliced into the wire loop. The photo below left shows the link from the jib halyard wire and the soft rope tail.

The purpose of this arrangement is to enable the join between the rope tail and wire halyard to travel easily over the sheave in the Jib box. The Jib wire can then be dropped to the deck level to enable the top swivel to be rigged and derigged for each sailing session. Using the long rope tail, the soft wire loop can then be pulled back and forth into the Jib Box and to permit the main Jib tensioning hook to be attached to the wire loop ready for the full tension to be applied.

Care must always be taken to avoid trapping the rope tail between the wire loop and the tensioning loop (See photos below).

Trapped rope in danger of being cut through when tension applied                                 Correct hook connection, clear of rope

 The Jib Tensioning System

The Jib tensioning system consists of a single 2.5m length of 4mm Dyneema rope arranged as a 4:1 block system.

The Jib tensioning rope is anchored using a Larks Foot knot situated approximately 60cm from one rope end (See diagram above). The short end is fed through the main 25mm pulley block and tied to the loop on the loose 20mm block using a Bowline knot.

The other end is then fed through the loose 20mm pulley block, down by the cleat and through the lower block fastened to the bottom of the mast. The end is terminated in a bobble or large knot to prevent the rope from being pulled through. The position of the Larks Foot knot may need to be adjusted to ensure that when normal tension is applied the position of the main and loose pulley blocks allow for further tension to be applied in circumstances when maximum tension is required.

Many Xenon owners place a position sticker on the mast, alongside the Jib Halyard slot, so that the position of the main tension hook can be noted, enabling a particular rig tension setting to be repeated in the future.

Jib System Specifications