Making a Super Maxi Mast

Tuning the rig was the easy part. Not simple, but when it was finally time to step and rig the 186-foot carbon mast on Esense, a 143-foot Bill Tripp-designed Wally Yacht, Hall Spars had been working on this particular piece of equipment 18 months. From "Grand Prix Sailing" in our August 2008 issue

Rolex/Carlo Borlenghi| |Esense racing in Porto Cervo, Sardinia, Italy| February 2005: Ben Hall is on the phone and he's explaining that Hall Spars is 25 years old, has a new plant in Holland and, more recently, put a new building up in Bristol, R.I., double the size of its old one. They've got a new, longer autoclave and paint booth. Not that they've built a mast that long yet, but as the company VP suggests, with AC masts on order from Alinghi and the superyacht market heating up, it's all about to happen. In fact, Hall is about to start a 186-foot mast in the spring. Would I like to watch them build it? Yes, please.

March 2005: Stephan Lavalle, of Bill Tripp Yacht Design, is on the phone, telling me about Esense, already under construction at Wally Yachts in Italy-the biggest Wally to date. It's a bit of a departure from previous Wallys, styled after America's Cup boats with bulwarks all around, and an all-carbon hull. Racy, but not a racer, he says. It has a lifting keel and the carbon Hall rig will carry a carbon Marten Leisure Furl boom. Composite rigging? I ask. We went a long way down that road, says Steve, but chose standard nitronic rod not for safety but for its lower cost (roughly a quarter million, I learn later). The rig will carry heavy loads and with its 25-degree aft-swept spreaders will remain static; no bending it to flatten the main.

A couple days later, round the table in Hall Spars' Bristol office sit Dave Moffet, the project manager; Phil Powell, chief engineer; Kenny Madeiro, laminating department foreman, and Jim Gagnon, pre-assembly chief. Considering it's the biggest mast the group has ever built, the discussion seems remarkably ordinary, although I detect a little tension in reviewing the engineering and production schedules. Nobody's saying, but some America's Cup masts they'll be building at the same time could be a factor. The conversation includes terms I know and others I can only imagine-mandrels, dry splices, patching, and wrap plates-and whether parts will be new designs, requiring new tooling, or modifications of successful older ones. Also, will they be built in-house or not?

"We always try to make parts ahead of time," says Madeiro, and suddenly I realize this isn't about the greater length of the tube they're going to be laminating (two tubes, actually, as this mast will be laminated in two sections and then spliced together). The challenge of this project is the rapidly multiplying number of parts-spreader tip cups, goosenecks, light brackets, lifting bars, conduits, water stops, vents, and more. In business terms, company president Eric Hall tells me later, it's not a question of our capability, but whether we can build it in a timely way.

One thing really confuses me. The department heads are discussing a ramp they're going to build for the mast, but they can't decide if they'll cut the frames for a female mold in-house, then send it out for manufacturing, or if they should spend $40,000 using a CNC router to make a male, foam mold. For me, the question is only perplexing because I have no idea what use a supermaxi mast will ever have for a ramp.

John Burnham| |A spreader gets "debulked"" in the laminating room.|

June 2005: In the laminate shop, a sixth layer of pre-preg carbon fiber (of an eventual 21) has been applied to a spreader (left), and Mylar film is being temporarily wrapped around it as the mandrel rotates. The clear non-adhesive plastic pushes air out of the laminate to compact the laminate with each new layer of carbon. (This may happen up to 130 to 150 times on mast sections.) All layers are unidirectional carbon except the first and last, which are woven to prevent splintering when drilled to add lights and brackets.

July 2005: Below, left, mounted on a slightly tapered aluminum mandrel is the upper section of the mast. The laminating crew puts down a layer of tacky carbon fiber at 0 degrees orientation to the mast (used for handling, the brown paper backing will be peeled off). Other unidirectional layers will be at 45 or 90 degrees. The pre-preg material is stored in a freezer until ready for use and will stay tacky for a month at room temperature. Engineering has provided Madeiro and his team with a layout depicting where the fittings and spreaders attach; at each of these points the mast is reinforced by an "isoplate," which is a stack of unidirectional carbon oriented at 0, +45, -45, and 90 degrees, topped by a woven layer. A layer of woven fiberglass is used where needed to provide insulation from aluminum. This section will take two weeks to be ready to "cook" in the autoclave.

John Burnham| |One of more than 100 layers of carbon goon the upper mast section.|

August 2005: Perhaps due to the America's Cup masts on premises, I wasn't invited to watch the mast sections go into the autoclave where they were baked overnight, first at 170 degrees F for 75 minutes and then at 255 degrees F for two hours. Vacuum-bagged, the carbon cooks with six atomospheres of pressure pressing it against the mandrel, which expands in the heat, but can be removed when it cools and relaxes. The cooling process takes place slowly, to avoid micro cracks in the laminate.

February 2006: In Gagnon's shop, the mast sections and parts are ready for dry assembly before painting. At left, parts awaiting placement include collars for mast-base turning blocks, the lid for the masthead, the lifting bar for the mast-base hydraulic tensioner, and the vang gooseneck. Inside the upper mast section, a pair of tracks hold Kevlar conduits with messenger lines for wires to be installed after the sections are spliced together.

John Burnham| |Tracks inside hod wiring conduits.|

Courtesy of Hall Spars| |**In the pre-assemble shop, Jim Gagnon drills a hole in the masthead assembly for a lightning rod holder. **| March 2006: The masthead crane has been glued into the machined opening at the top of the mast, then reinforced with extra carbon cloth wetted out with an aerospace-type epoxy. The backstay attaches to a pin that inserts through the crane near Gagnon's head. The main halyard sheave is pinned through the hole to the right of his drill and the 2-to-1 halyard is dead-ended at a pin through the hole by the Hall Spars logo on his t-shirt. Two masthead sheaves are available on the front of the mast (at bottom); the headstay attaches a few feet below the masthead.

Courtesy of Hall Spars| |**Another part gets fitted in pre-assembly: the ramp that will guide the mainsail luff from the mast groove to the roller-furling boom. **| March 2006: Here's the missing ramp being positioned on the back of the mast for gluing. It's a tapered, 45-foot piece that guides the luff of the mainsail away from the mast and smoothly into the roller-furling main boom.

Courtesy of Hall Spars| |**Shipping day in Bristol, RI **|

May 2006: Painted with a clear coat and prodigiously wrapped, the two mast sections load for the road, their last day in Bristol, R.I. They're headed now for a ship in New Jersey and delivery to Ravenna, Italy, on the Adriatic. The boxes around the mast provide protection to parts like the masthead crane (far left) and serve as lifting points and resting points while at sea.

July 2006: Spliced together with all parts in final assembly and rod rigging attached, the four-spreader rig goes skyward at Marina di Ravenna. The all-important splice was fitted "dry" in Bristol; an insert or splice piece that exactly fits the inner contours of each section and is drilled and screwed in place, then taken apart. Once in Italy, a Hall team led by Jim Gagnon reassembled the splice, gluing in the splice piece, then gradually tightening the screws to compress the bond. Finally, a layer of prepreg carbon covers the splice and it's clear-coated and buffed to appear as one seamless spar.

Courtesy of Hall Spars| |Rabenna, Italy: Filly assembled, Esense's spar is ready to step.|

September 2006: More than three years after the contract was signed with Hall Spars, and 18 months in building, at last, the largest Wally yet is ready for a classic Wally photo shoot. Esense struts its stuff and demonstrates that fast, push-button sailing can be had on a yet-again-larger and more dramatic hull. Meantime, about the time we went to press, a five-foot longer Wally and 10-foot taller Hall Spars mast set sail in Esense's wake. For a photo gallery of Esense's surprising interior and its larger younger sister, see www.sailingworld.com/0708esense.