C&C 27 Association – Tuning The Rig, Mk V

Whether you race or cruise, it's worth taking some time over rig set-up. The boat will be quicker and easier to sail. If you race, you may want to use a tension gauge to check your settings, but a tension gauge is only a time-saver, not a necessity, because the whole point is to get the mast to behave a certain way on the water – basically to be straight and centred over the boat, with just enough rake to eliminate weather helm in your average sailing conditions – and this state can be achieved by trial and error on the water.

The following process description was submitted to the Forum by Steve Reid of Still Knot Working in Toronto (a Champion in the class). Steve mentions using a Loos Pro tension gauge and a tape measure (50 or 100-ft), but these aren't absolutely necessary unless you are racing. In lieu of a long tape measure, the site admin hooks a collapsible boathook into the main halyard, adjusting that to just touch the toe rail on one side, then adjusting out any variation on the other side, until the masthead is amidships. A small tape measure will be necessary to measure rake, which typically is done by hanging a heavy object from the main halyard, then measuring the gap between the aft face of the mast at the gooseneck and the halyard. As a starting point, shrouds should be tight on both sides in the winds you normally sail in.

Running your turnbuckles up this tight cannot possibly damage anything that isn't already looking for an opportunity to break, but it can cause galling of the turnbuckles if they're not greased or oiled when you work (saltwater sailors may prefer anhydrous lanolin). Slather on lots, then wipe away the excess when you're finished.

Mk V rig tuning

The first step is to print C&C's original Tuning Guide for the Mark V. I have found that we need the maximum amount of rake to get the boat to point, so I go with about 16".

The next issue is to get the mast centered in the boat (side to side). I add a spare sail slide in the mast track (put it on before you feed the slides for your main so it sits above the other slides), then I use the main halyard to hoist the slide, with a tape measure attached, up to the top of the mast. I do this because the main halyard does not exit the top of the mast at the centreline – it's offset to one side. I measure to a fixed point on each side (the deck at the toe rail is best) directly abeam of the mast.

I use the intermediates to centre the mast initially (they are in fact the first thing that I adjust) and because they are located so close to the uppers at the chain plates that it's really about the only way you can tighten them. I only tighten them more if I find that the mast is falling off to leeward between the spreaders and the masthead under sail. Tension your uppers to get the masthead in the centre of the boat and then adjust the lowers to keep the mast in column.

Once you have the mast in the centre, you will need to tension to get the correct load on the rigging. Make equal adjustments by counting the number of turns, tighter or looser on the turnbuckles. I use a Loos Gauge Pro (there is a difference between settings made on the standard model and Pro) and I'm at 28 on the uppers and 25 on the lowers. I don't have a value for the intermediates because they're so small. This tension will induce a good amount of pre-bend into the mast with a slack (hand-tight) backstay. Pre-bend is important to the boat especially if you have a fairly full mainsail. If your main is cut flat, then less pre-bend; if it's full, more pre-bend. The other thing you want to check (this will also affect pre-bend) is the arrangement of your upper shrouds and the intermediate shrouds (if your boat is equipped with intermediates – some of the early boats weren't). The uppers should be in the aft slot at the spreader ends, and your lowers should be in the aft hole at the spreader roots. If they are in the forward hole, they will inhibit mast bend.

Once you have the rig set up, you need to pay attention to how you have the boat set while sailing. It's sensitive to mainsheet tension and traveller car placement.

My boat has a solid vang and we "vang-sheet" the main. It's a fairly full sail with a maximum roach so we have to be very careful to not over-vang/sheet the sail or the leach acts as a brake. We set the vang to get the shape we want and then play the traveller to get the amount of helm I'm comfortable with in the given conditions.

Headstay sag is another factor that seems to affect the Mark V. We generally go with a very straight headstay (very little sag) in anything except very light (under 5 kts.) or very heavy conditions (over 15 kts. with big waves), in which case we slack the backstay off a bit to give the genoa a little more shape.

Genoa sheeting on my boat is to the cockpit coaming track for the #1 & #2 and to the deck track (about 4 -5 holes back from the front end) for the #3.

Keeping the crew out of the cockpit is good, but where you place them on the deck is critical also. On my boat, the only people allowed in the cockpit most of the time are my jib trimmer who lives on the primary winch and works the trim constantly (she weighs about 130 lbs.). My main trimmer/traveller person (about 140 lbs.) sits on the deck as far forward as possible while still being able to work the sheet and traveller controls. The helmsman (I'm a big guy – 230 lbs.) sits to windward with my forward thigh right up against the aft side of the primary winch. If it's light (under 5 -6 kts.), then I'll often sit to leeward in the front corner of the cockpit.

In general upwind, the boat likes to have the weight centered on the rail more aft than forward (use the cabin windows as a reference or keep the crew stationed between the 2nd and 3rd lifeline stanchions). As the wind lightens, move the crew forward and inboard, but the furthest forward anyone should be is the shrouds. As the wind increases, move the crew aft and outboard. Downwind, weight in the back of the boat is deadly. You have to keep the bottom edge of the transom out of the water, especially in light to medium conditions (if you hear gurgling, you are slow). When the wind picks up, the boat needs weight aft to keep the stern down and prevent it from rounding up under spinnaker and broaching, so I start moving people to the stern rail until I have good control and the rudder will keep the boat steering.

Choreographing the cockpit

First of all a bit about equipment: the traveller system on my boat is a Harken Windward Sheeting system – not cheap but worth every $$$$ in my opinion. With the Harken system, there is no need to release one side as you tack to be able to adjust from the new windward side. The device does it automatically for you. When the boat tacks and the load on the traveller car changes from one side to the other, the old windward side cam cleat opens and the new windward side cam cleat closes. The previous owner installed Harken 18 self tailing winches as primaries and I bless him every time we are sailing.

So now to the choreography:

The Main Trimmer sits on the windward side on the deck with her forward butt cheek resting against the aft cabin bulkhead. When I call for a tack she gets ready to move but doesn't move till I say "ready about". As I say "helms-a-lee" the Main Trimmer moves to the companionway (centre of the boat). As the bow crosses head to wind, the Main Trimmer looks up (she's facing aft), makes sure that the leach of the main has cleared the backstay, grabs the new windward side traveller control line, moves to the new windward side position and adjusts the traveller.

The Jib Trimmers: In light wind (<8 kt.) the Jib Tailer sits on the windward rail/deck, just forward of the Main Trimmer and the Grinder is sitting to leeward constantly adjusting the Genoa. If it's blowing (10> kt.), the Grinder sets the Genoa and sits on the windward side immediately forward of the Main Trimmer with the Tailer now sitting just forward of the Grinder. When I call for a tack, the Grinder and Tailer get ready to move (get the blood flowing in their legs) but they don't move till I say "Ready about". When I call "Ready about", they both move. If the wind is less than 8 kt., the Grinder has simply to move across the cockpit to the windward primary. The winch has already been preloaded with turns of the lazy sheet so the Grinder needs only to the Windward Primary and insert the winch handle. The Tailer moves to the leeward forward side of the cockpit, her forward thigh just aft of the traveller, where she grabs the lazy sheet and pre-tensions it. As I call "Helm's-a-lee", in light winds, I simply move aft just before the tailer moves into her position. In stronger wind, I move across the cockpit and release the genoa sheet from the leeward primary. As the boat comes head to wind, the genoa is released and trimmed in on the new tack, while I oversteer slightly to allow the boat speed to build as the Genoa is trimmed in. Also, I preload the new windward primary and move into my steering position – under 8 kt. from the forward lower corner of the cockpit, and above that, from the windward side cockpit coaming just aft of the primary.

– Steve Reid, Still Knot Working, Toronto