No doubt many of you have either long since given up on setting up a jib on an AI, or coppied Sterling or Tom Rays incredibly innovative ideas. I have put one on my AI, and in winds up to 15mph it does assist performance, but trying to sail on just the jib alone is a no-goer, the centre of pressure is too far forward and consequently 'steers' the rudder, in other words it has a stronger effect on steering direcetion than the rudder can overcome...it has a mind of its own.
However as a gentle to moderate wind tool, it is quite useful.
I made a simple phone request for a jib for my Adventure Island to Danny Allen, Binks Marine’s sail-maker at Somerton in South Australia (firstname.lastname@example.org
). After tossing around a few ideas mainly from Tom Ray in Florida USA, Danny made up a beautiful jib to compliment the red and white mains’l of my Hobie Adventure Island which gave a total sail area of 7.8²m, ½ metre less than the larger Tandem Island.
Out on the water I found that the system I had suggested was quite practical if you are still in relatively calm conditions for raising and setting or lowering and retrieving the jib. Unfortunately, a life on the ocean waves is subject to quite unexpected change, and due to the sudden wind gusts we can experience in Darwin the task became awkward and difficult to manage if the wind suddenly turned on the fresh side of brisk. Twice, being caught between caution and ‘ah…she’ll be right mate’, a sudden strong wind was upon me by which time I had difficulty ‘luffing up’ to lower and haul in the jib in an efficient, sailor-like manner… my antics being more reminiscent of a one-armed paper hanger caught out at the top of a ladder about to hang some freshly wet glued wall-paper when somebody enters a room letting in a gust of wind to make things interesting!
It was time for an alternative plan. I made (rather than bought – since this was an experiment) a jib furler. Basically, I found a Royobi whipper snipper head from the dump…sorry, the recycling centre! The non-rotating part I attached to the bow eye-pad, the rotating part attached to the tack of the jib, with a swivel at the head near the top of the mast. Not being an innovative sort of bloke I amazed myself - the unit worked, well it was able to rotate freely without binding up – but hang on, if you’re handy with tools, (which I’m not) don’t race out to the workshop just yet…
I used the unit several times, but got my feet all tangled up in several metres of line from the furler and halyard floating around in the cockpit (I know - poor seamanship). Additionally after raising the jib the unfurling action became a frustratingly delicate and awkward production. This was apparently caused by the light 2mm luff line sewn into the jib not being able to hold anywhere near the stiffness of a wire fore-stay, nor was it designed to in the original plan. Consequently a kink formed in the furled jib due to too much pulling pressure applied in one spot when hauling on the jib sheets to unfurl it.
I remedied this by converting my jib furler to a continuous line type. This was achieved by wrapping a large size #109 rubber band around the free turning part of the furling spool, the idea being to give the continuous loop of 3mm line something to grip on. I then took two turns of the 3mm line around the spool so it would not slip and fed both ends out through an enlarged hole in the fixed cup of the furler…this line then runs back to the cockpit. Now, in a two handed action, pulling on the continuous line and following with the jib sheet, the operation smoothed out. I reluctantly tried it under real ‘at sea’ conditions, deliberately going out on a windy day (20kts) with waves washing across the fore-deck. After luffing up, I tried both actions and was relieved to find the operation of furling and unfurling difficult but manageable.
My next problem presented itself when the upper part of the jib was still not quite completely unfurled making it an inefficient ‘aerofoil’. Not intending to race (I have the only AI - and there are no TI's - in the whole Northern Territory of Australia)this was not a performance consideration, but onlookers in another boat would see what looked like the efforts of a lazy and/or incompetent sailor who didn’t bother to check the sail trim. This was due to twisting of the luff line in the jib despite the free moving head swivel.
To over come this I installed a luff spar (same fibre-glass material as used in the A I mains’l battens but a little thicker, about as thick as a pencil). The fibre-glass spar stiffens the luff thus allowing the jib to furl and unfurl evenly between the head swivel and the furling drum. The luff spar is drilled to secure it to the sail using ties at the tack and head which are tied into metal eyelets at those jib points. To prevent the possibility of splitting the spar at the tack which takes most of the load I added a five centimeter long 12mm aluminium tight fitting sleeve over the tack end of the spar as it had to be drilled to accommodate the tack-end shackle. Undo the ties and the luff spar can be removed from the jib for storing it in its bag. The luff spar also overcame the kinking problem when unfurling the jib, so it worked even better… Job done!
However…I then pondered the convenience of being able to reef the jib as well as furl it…I quickly learned that my furling system even with a stiff luff spar in the jib will not do both jobs.
The furling set-up needed to be ‘locked’, and the answer was as simple as fitting a cam cleat just ahead of the ‘rudder raising toggle’ to lock the continuous line to the furler drum. The jib can now be reefed as required and the jib sheets able to be used in the normal manner without the jib unfurling. If the jib is no longer required I can neatly furl and stow it down the port side. It is a great improvement to be able to reef the jib to whatever degree of sail area is required if wind variations on tacking headings dictate reefing as a more efficient course of action than having to completely furl for one tacking leg if the wind is too strong for the heading steered. Of course if conditions turn bad enough to require reefing of the main, the jib still has to be lowered, unclipped from the halyard and stowed first. With the system I now have rigged, even under stressful gusting conditions, the jib can be furled, lowered and stowed then the main reefed to take the strain off the mast all in a few minutes – no doubt faster for a younger bloke (I'm 72) with practice.
The first time I tried the finished set-up in what had been gentle conditions, I got caught out (again) by a sudden rough and windy change a few kilometres off shore with a wind blowing at 30kph and gusts to 46kph (anemometer measured) but was able to luff-up, furl the jib, lower it conveniently wrapped around its luff spar and stow it down the port side taking up no room at all…without the need to be folded and stowed in gusting conditions with waves breaking across the fore-deck and into the cockpit and so avoiding a repeat of the one-armed paper-hanger episode.
[quote] If it ain't broke, try modifying it anyway! quote]