Boat test from Boating New Zealand

Clissold’s first design was a Viper 5 which he sold several years ago to relative obscurity in Lake Taupo. He has designed three 5.5m International A-Class catamarans, and his TC790 design, Hard Drive, based in Auckland. Other boats of his design are under construction around the North Island. Local legend has it Clissold will argue his theories of multi design late into the night, against similarly determined, local multi maniacs, although you wouldn’t pick such feisty determination on early meetings. He has the engaging friendliness of a rural dwelling Kiwi and looks younger than his 36 years.

Pulse designer Tim Clissold, right, and regular Pulse crew Rowan Halkyard often sail the boat two-handed.

Consider then he has been able to leave boatbuilding to design full time and has put his money, his mouth and five years of his after hours time into creating a boat which puts his distinctive design strategies where they belong on the water. Enter a 10m catamaran named Pulse. Clissold built the TC 10 in a farmshed he rented for $25 a week. He expected it would take two years; the time constraints of having to earn a living meant it took five years around 2500 hours and $100,000 in materials. Even three years after its planned launching, Pulse stands out as innovative in the fast moving world of multihulls. Had Clissold given himself a brief for this boat, it would have included accommodation for six people, large friendly cockpit, lightweight construction, and fast performance.

2) The hatches in the transom open straight onto the aft double bunks, providing good air flow through the boat at anchor and an easy check on the anchorage.

3) Tim Clissold designed the boat to keep crew weight out of the after end of the cockpit; all con-trols including the helm are well forward.



4) Having no boom to worry about makes for relaxing sailing.

5) The cockpit is well clear of equipment, with controls placed on the central pod or at the mid-point either side of the cockpit.

6) Control lines to raise the rudders run through carbon fibre tubes in the tillers.

Looks were important. “I wanted it to be very organic,” says Clissold, “with soft lines instead of hard edges, but without compromising the practicality of the boat. You still need to be able to walk around it easily without losing accommodation. The hugest call was the transom, but I’ve got away with it. I didn’t want another ugly cat. “If someone had come to me and asked for all that,” he admits, “I would have said, ‘No, it can’t be done.’” Pulse has proved otherwise over 1,000nm sailing since launching. Most of it was during an 11-day cruise to Coromandel, the Mercury Islands and Tauranga, which included facing large swells from Cyclone Waka. Much of the trip was sailed two-handed. I met Clissold and his friend and regular crew, Rowan Halkyard at the Sandspit wharf. Curves, blessed with effective non-skid, greeted my first steps over the starboard hull and into the cockpit so bare, it resembles the scene of a burglary. But bare, in a good way, bearing out the designer’s wish to provide generous seating and safe, clutter-free sailing. Initially it appears the burglars have stolen the steering but just aft of the mast is a console which houses the outboard motor and provides a base for the halyard/headsail winch and engine control. Just aft of this is a whipstaff, last heard of by me as a means by which mariner David Lewis steered his yacht Icebird from inside the cabin in Antarctic waters. For those young-timers among you, a whipstaff is a vertical form of a tiller; pushing it to starboard turns the boat to port, and vice versa, as you would expect. Beneath the cockpit floor, a system of Spectra ropes and blocks controls the twin rudders. Why the whipstaff? It keeps the crew weight, estimated for design purposes as 270kg of movable ballast, out of the stern, particularly beneficial since catamarans tend to trim down by the stern anyway. All heavy items, such as the 80amp/hr, deep-cycle battery, fuel, anchor and sails are stored in the middle of the boat. Twin wheels would be an option on the TC10 but would detract from the wide open space. It is possible to steer by the tillers and linked rudders but that puts the helmsperson’s weight back at the transom.

Out from the wharf in front of the new Sandspit Yacht Club, poles define the limit of the deep water. Manoeuvring Pulse out to the channel with the 15hp Honda mounted in the central pod had its challenges; twin outboards on either stern would give better steerage but, again, put weight aft. Clear of the wharf I tried the whip-staff steering as Clissold and Rowan Halkyard set about hoisting the mainsail, which has three reefing points. I had noticed that beneath its cover, the mainsail seemed to represent a fairly ordinary flaking job – it soon became clear why: no boom. Those burglars again. Clissold’s prime motivation for dispensing with the boom was crew safety. “The most lethal part of a boat is usually the boom and if it does knock some-one overboard they usually have a head injury,” he reasons. It also saved the weight and cost of a gooseneck, boom vang – rare on mulithulls and associated boom fittings.
Throughout the day and evening I spent on the boat, it was nice never having to dodge the boom, especially since the whipstaff steering places the helmsperson well forward beneath the mainsail. Clissold says getting his head around the boom-less mainsail was a major until he had the reefing sorted. “You don’t have a boom on a jib,” he reasons, “so why have one on a main? If you get your sheeting angle right, you don’t need a boom.” When lowered, the mainsail rests in its hammock-like cover with webbing beneath for drainage, and supported by

He lives in the small town of Warkworth, north of Auckland. The Sandspit harbour nearby is a multihull mecca: Impreza, Razzel, Sonic, Slime. If you wonder why, check out their moorings at low tide: shallow draft city. An oval in the cockpit floor raises up, ironing board style, to provide al fresco dining.

The clew of the mainsail has a carbon clewboard, similar to a mainsail headboard, which provides a base for clamcleats for reefing, the topping lift and the mainsheet this tensions onto the curved traveller which runs across the rear beam. The controls for the mainsheet and traveller are directed to winches either side of the cockpit, next to where the helmsperson sits when using the tiller extension. Placement of controls and the clear cockpit make the boat ideal for short-handed sailing. The boat has a cruising mainsail, high cut to keep clear of heads, and perhaps a bimini top in the future. Clissold plans to add a lower-cut racing mainsail. The main and jib are Dimension Polyant cruise Mylar.
The lazyjacks tend to foul the mainsail’s full length battens during the hoist often a problem with lazyjacks. When first hoisted, the mainsail looks dreadful without the weight of a boom to pull it down and requires significant cunningham tension to set the luff. Clissold hasn’t labeled the controls but their placement is so logical that even newcomers quickly work them out. The self-tacking jib, with one reefing point, has a power head to help twist the sail in gusts. “I don’t think overlappers go faster and it is better to have height than overlappers,” Clissold says. “You have better reaching with a self-tacker as you still have ideal sheeting positions to the jib.” Clissold hoisted the outboard motor clear of the water on a 3:1 purchase. It rests in its pod a generous metre clear of the water, raising its fairing with it to preserve a clean line to the bridgedeck and protect the motor from spray.

As we headed out to open water I battled with the whipstaff steering. I wasn’t particularly sold on it although Clissold says this was the mark four version and there would be more development yet. In principle it works and makes a lot of sense, but is stiff to use. “I’ve tried out so many new things on this boat,” he says, “there are bound to be some problems.” We had 15kts north-easterly, sunny skies and a slight chop. Pulse’s top speed upwind has been recorded at 12kts but our highest Pulse rate upwind was 11.3kts, with the skipper on the helm. A reach clocked a top for the day of 19.4kts although the boat has recorded 22kts. The boat tacks through 90 degrees with a determined shove to the whip-staff from the helmsperson. Like all catamarans it is important to keep the speed up; let them stop and they take a while to get started again. Which brings us to hull shape. Clissold developed his design theories

LEFT: The whipstaff steering borrows from an older style concept to become an innovative feature on this modern multihull. RIGHT: As the self-tacking jib tacks, the windward traveller tail pulls on the mast spanner at the base of the mast to help rotate the rig.

Tims opinions on hull shapes having sailed on most of the Auckland racing multihulls, and smaller cats such as Paper Tigers and Tornadoes. Unlike planing monohulls, he believes, most older multihulls fail to use their speed as lift, relying solely on buoyancy to keep the bows up. “I like to have a shallow forefoot to encourage the water flow under the hull to lift the bow,” he says, “while a wide transom helps to carry the inevitable crew and gear load that accumulates aft, as well as suck the stern down. But a pure round hull form underwater is painful upwind as it pounds, which shakes the rig and sails.

So the hull is vee-shaped forward, and flattens on the run aft, which makes for a softer ride.” As he points out, the crew can quickly tire from excessive spray at fast speeds so the hulls have spray rails to deflect spray down, while providing lift. In flat water the boat can be sailed fast without driving spray onto the crew. During our sea trial, we sailed upwind in about 16kts true wind speed and two-sail reached at speeds up to 19.6, with nary a lick of spray over the bow. Any catamaran driven hard enough in choppy seas will eventually go through the odd wave. Pulse’s rounded foredecks shed water quickly. A low profile windscreen is to be added to reduce wind chill on the crew. Clissold drew the hull shapes on MaxSurf software. They are symmetrical below the spray rail, but flare into a chamfer panel on the inboard side to reduce the connection angle between hull and beams, reduce the beam length, and provide more accommodation in the hulls. Not surprisingly, the 92kg rotating flexible wing mast has been the most challenging part of the commissioning process. As with every other part of the boat, Clissold designed and built it with inspiration from Frank Bethwaite’s book, High Performance Sailing. The mast has what its builder calls a chopped off trailing edge, which encourages the flow to change from laminar to turbulent, and remain in touch with a larger area of the sail. It is Double sealing more power! Simrad Tillerpilots with double sealed electronics Simrad CockpitPilots TM combine attractive styling with storm proof weather protection. These Autopilots are characterised by high thrust, low power consumption and quiet operation.

The mast is built from stressed plywood and cedar, with carbon fibre vacuumed on. All fittings are carbon; the terminals are Vectran, easily adjustable. Since it has no spreaders, the mast has large panels, that is, areas without direct support, so the tension of the stays is crucial. Even on the day of our sea trial, the mast had its moments of doubt about staying upright, a result of the Spectra lower forward sidestays stretching and compromising their support. The Spectra will be replaced with Vectran; wire rigging wasn’t an option due to the shockloading. Topmast stays may be added. I was impressed with how easily the mast turned during the tacks, due to help from the self-tacking jib. Very nifty: as the jib self-tacks, the windward traveller tail pulls on the mast spanner at the base of the mast, bringing it round. The mast’s rotation is also helped by the absence of a boom, which would apply compression to the mast. The boat has been built to survey, although is yet to undergo the final certification. We hoisted Clissold’s self-made 3 /4 oz nylon gennaker, high cut but still needing work in the leech to stop flapping. Trimming was easy, perched on the hull behind the winch, and dropping the sail was a breeze, on the trampoline. Speeds under gennaker were 10 - 13kts; in the light breeze at the time we did better two-sail reaching.

There is also a Mylar screecher on a custom carbon endless furler and an orange storm jib, all made by Clissold. We headed over to Vivian Bay, Kawau for lunch as the wind increased to around 20kts on a tight reach. By this time, Clissold had brought out the tiller extension – a piece of aluminium pipe with a piece of string looping it over the whipstaff. Obviously a temporary make-do but it did mean I could sit on the hull, right next to the mainsheet, to steer. The blast reach home was the best and in a stronger breeze, I had a better feel for the boat through the whipstaff but multihulls require their own brand of handling and I’m the first to admit I still haven’t got the knack in terms of boatspeed. But this was fun and gave us the fastest averages for the day, consistently around 16kts.

One thing I noticed about Pulse at speed: she’s quiet. The mast doesn’t squeak, the rudders and centreboards don’t hum, the structure doesn’t groan the sign of a well built multihull. The rudders and centreboards are kauri-cedar-carbon-glass, laminar flow foil sections and are retractable for shallow draft areas. The centreboards have sacrificial crash boxes on their lower portions and lift on a 2:1 ratio of pulleys. The rudders raise through a nifty Pink, as in Pink Floyd: the accommodation is surprisingly spacious.

The photograph to the left looks forward past the galley in the starboard hull; the other view is aft from the galley.

system, coutesy of a cord through a carbon fibre tube in the tiller. When we arrived back at Sandspit, someone had pulled the plug, on a low spring tide. We raised the rudders and boards as much as we dared and, with little steerage as a result, managed to make the wharf safely with only the occasional tap of a rudder on the mud.

An hour later, we were joined by friend Margie Baker and motored out to Shark Bay for a barbie. A stingray, the ultimate shallow draft design, erupted as we closed the shore. An oval in the cockpit floor rises, ironing board-style to become a table admittedly with a lot of grunt and Halkyard served dinner from the galley. The stereo sang, the sun set, the Chardonnay was nicely chilled. Supposedly, TC stands for Tim Clissold, but, just as apt: Top Cat.

Construction Four weeks before the Lindauer Coastal Classic race last year, Clissold had two hulls, two beams and a fore-beam. Massive efforts from friends and family made the five pieces, plus appendages, into a catamaran in time for the startline although stretching stays resulting in a wobbly mast saw them pull out in the early stages. In deciding on the construction method, Clissold wanted to keep it simple enough for an amateur builder, with perhaps a little help the forebeam, for example, is a complex composite structure. The build also needed to be modular since the finished boat would not fit in the building shed. He began with vertically split female frame and stringer moulds, set up on their sides. The foam was bent in strips approximately 300mm wide athwart-ships and trimmed off between cedar rails at the centreline and spray-rail. The hulls are effectively planked with a sharp knife and straight edge. The interior skin was added later.

Some decisions were financial: the cockpit floor in foam would have cost $1200 but only $300 in ply just 20kg heavier. The hulls are foam rather than cedar because it saved 200kg. There is 9mm ply running athwartships and four girders in the bridgedeck. The hull materials are: 760gm/m 2 Triaxial E-glass on the outer skin, 300 gm/m 2 Kevlar below the waterline, 10mm Herex PVC foam core, and 650 gm/m 2 Biaxial E-glass inside skin.

There is carbon reinforcement in the ring frames and chain plates. draft 0.40-1.6m mast height 14.8m upwind sail area 63m 2 gennaker: 72m 2 screacher: 38m 2 dry weight 2000kg water capacity 250L price materials $100,000 finished boat $250,000

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