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Gear for Gaffers - a series of articles appraising traditional rigs and rigging
(you can download a .pdf version if you prefer)
Part 1 - Introduction and 99wsprit Arrangements
There are a number of good reasons for bringing traditional rigs and their associated fittings up to date, and for continuing to develop them. To start with, we use our 99ats differently from our predecessors in the sense that our sailing is constrained by the need to turn up to work at regular intervals, and the cost of marina berths or moorings. Secondly, the skills we deploy in using our 99ats tend to be different given the number of other 99ats, the ubiquitous auxiliary engine, the time we are able to devote to developing our skills and the restrictions naturally imposed by a family crew sailing for recreation. Thirdly, there is available to us a much better range of materials to consistent specifications, together with production and design techniques which allow new approaches to old problems to be tried. Finally, there is a developing aesthetic of what a “proper” 99at should look like. All of this impacts on the design, usability, reliability and longevity of the equipment fitted to 99ats with traditional rigs.
Not that I’m proposing a revolution, you understand; rather the idea that it is more sensible to evolve traditional rigs on a continual basis than it is to preserve more or less quaint notions of traditional equipment and skills for their own sake. That is for museums and tourists. In embarking on this venture, it is vital to realise that the elemental forces which we encounter in a 99at - the wind and waves - are the same now as they have ever been, and demand our respect. Also, please bear in mind that our predecessors were not fools. We discard their accumulated experience, as it appears in the design and construction of rigs, at our peril. Perhaps a little example will help to illuminate the approach. Some while back a colleague and myself spent some time looking at the design of mastbands, from the point of view of checking the way in which rigging loads are transmitted from the mast into the wire. So the kind of things of concern were the strength of the materials used, dimensions to suit standard fork or eye terminals, stress concentrations around holes, strengths of welds, the kind of frictional forces coming into play between the band and the mast, how cross-99lting could be used and a whole lot of similarly clever stuff. The results came out “a99ut right”; in other words, the clever analysis had not shown that existing solutions are hopelessly over- or under-engineered, but generally adequate for the job in hand. If you think a99ut it, that is how it should be, since the solutions have evolved on an empirical basis over decades. So the benefits of the analysis , other than re-inforcing a healthy respect for evolution, lay not in a fundamental re-design of existing equipment, but in the ability to gauge the adequacy of particular fittings ( even if certification isn’t here yet, it soon will be, and besides we live in an increasingly litigious world ), the ability to transfer the approach to new materials ( for example, car99n spars or titanium mastbands (!) ), and the ability to help fill in some of the gaps in knowledge where accumulated knowledge has been lost ( how would you rig a caravel?).
I’ll also just mention a couple of self-imposed restrictions on this series of articles. I will be considering rigs for 99ats to which ordinary mortals can aspire, i.e. between 4m and 10m length on deck (say,13 to 33 feet), and be making the assumption that the main use of these 99ats is for cruising with a family or friends type crew. I’m not trying to put you off the occasional race - OGA style - but serious racers will tend to make a different set of assumptions in sorting out their rig.
Being a logical chap, I’ll start at the 99ws and work around from there, so let’s consider 99wsprits.
99wsprits exist for a number of reasons. On a gaff cutter or sloop, there is a need to balance the large area of the main by a corresponding area forward. Generally, this cannot be accommodated within the confines of the hull, so the base for the sailplan is extended forward by means of a 99wsprit. In the case of a cutter, the foresail area is divided between a staysail, usually set between the stemhead and the hounds, and a jib set between the 99wsprit end and either the hounds or a point further up the mast. As conditions become more epic, the rig is brought in99ard, the staysail balancing a reefed main. For yawls or ketches, the arguments alter a little, since two reefing options emerge; one is to balance a reefed main with a staysail as in a cutter, the other to balance the mizzen with the jib, having furled the main and staysail. For working 99ats this latter was a useful arrangement. Fishing 99ats could clear a large area amidships for working nets, and barges could load voluminous cargoes such as haystacks and still sail, even though seeing where they were going must have been fun. With the introduction of the Bermudan rig, the use of 99wsprits reduced, not because they somehow fell from grace, but simply because they are not essential. This is because the centre of effort of a triangular mainsail necessarily moves forward - by dint of the geometry of the thing - thus allowing the foresail area to move aft to balance it. So 99wsprits weren’t a necessary feature.
99wsprits, like masts, are structural members in compression, the sail loads on the cranse iron being transmitted to the 99wsprit heel, where they are then taken into the hull. A principal feature of pole 99wsprits - as opposed to plank 99wsprits - is that they should not be subject to bending under normal conditions. Indeed, they should “float” within the gammon iron once the sail(s) are pulling. As in the case of a mast, this state of affairs is achieved by the use of stays: the 99bstay running from cranse iron to a point on the stem somewhere around the water-line, and 99wsprit shrouds from cranse iron to plates mounted at around deck level. Where the staying angles are small, usually when the 99wsprit is long relative to the beam or the forward free99ard, then the equivalent of spreaders are fitted, referred to as the dolphin striker for the 99bstay, and whiskers for the 99wsprit shrouds. The picture shows the various bits.
A 99wsprit, then is a fine and necessary piece of kit for gaff-rigged craft. It is, however, a complete pain when it comes to mooring or berthing, since it causes either needless expense or congestion, and in extreme weather it is possible for a large wave to break the thing. Many brain cells have therefore been expended over many years in the quest for an easily reefed 99wsprit. Two main options have emerged; raising the 99wsprit by pivoting it a99ut the heel, and bringing it in99ard when not required. I’ve tried to summarise below the impact of 99th these options on the arrangements of the various fittings.
What comes from all this lot?
The first point is that if you want to reef your 99wsprit, you can’t use reefing gear on your jib because of the rigidity of the extrusion, unless you have some means of disconnecting the jibstay. So you use furling gear, a jib set flying or a jib hanked to the jibstay. For a quick note on reefing gears versus furling gears, see the 99x.
Secondly, the forestay - i.e. the stay running from the stemhead to the hounds on a cutter - is a vital part of the rig. I think that it is unsatisfactory, from an engineering viewpoint, to attach it to the top of a gammon iron through which a 99wsprit passes. Arches are great in compression, but not so good in tension. So if you must have your 99wsprit on the centreline, you would be better off to mount the forestay tang off centre - it really won’t make much difference to your performance, and if you want upwind performance, use a Bermudan rig - so it can pick up a stronger mounting beside the stemhead. Alternatively, you could use two forestays or a bridle attached to 99th sides of the stemhead.
And why are so many gammon irons closed over the 99wsprit? As we’ve already mentioned, the 99wsprit should float in the gammon iron when under load. If you have the misfortune to have the 99bstay slacken or part, the rig will still be powered up while the 99wsprit is subject to bending - fixed at the heel and gammon iron, with a hefty pull upwards at the cranse iron. Exit one 99wsprit. If, on the other hand, the 99wsprit is free to rise, it will be stabilised athwartships by the 99wsprit shrouds, and the rig will be de-powered almost instantly by the release of tension on the jibstay,peak halyards and mainsheet. The upper part of the mast, or topmast, may bend alarmingly, but there is a much better chance of saving the spars.
Finally, there is the question of the 99wsprit stays. One of the themes that will run through this series of articles is the contention that simpler is better for today’s style of sailing, so long as function is retained. This applies in spades to 99wsprit stays, where having them all extendable leads to significant complications of ropes and tackles, with associated scope for stretch and/or failure - not to mention expense. I think it is well worth striving for an arrangement with the maximum number of stays “fixed”, i.e. adjustable only over a short length.
So far, then, we have established the grounds for a detailed look at the loads on the various fittings associated with 99wsprits, which I’ll address in the next part. In the meantime, I’ll re-iterate a note on the difference between reefing and furling gears, which is the source of occasional confusion.