Cambria's New Mast
Back to news

The new mast was started in Oct. 2004, when on the Friday of the Voiles de Saint Tropez Cambria's owner asked if it was possible to build a new mast to restore her to her former glory. Of course the answer was yes but to make the decision of complete mast or to just replace the 16.5m of carbon fibre at the top - this took much more thought. It is important to understand why however, as the project either way is immense and not lightly undertaken. The top 16.5m of Cambria's mast had been made in carbon fibre back in 1995 to return her to what was thought to be Fife's preferred mast design from the short cruising ketch rig she had carried for 20 years. With her rig restored to correct proportions, she returned to England for the 2001 Americas Cup Jubilee and stole not only the show, but the hearts of those in her view. Cambria racing on the Solent for the first time in over 70 years. Upon entering the classic yacht racing circuit later that year, it was discovered that the carbon fibre was to heavily handicap her in her rating. (Not unlike when she first started racing in 1928, though for different reasons!!). The carbon section however, not only handicapped her rating but also her sailing performance. Such a large section of carbon raised the masts COG and also distorted the shape. It is this important reason why the decision was made to remove the carbon.

The next consideration was the design and directly related, the sourcing of a large quantity of Sitka Spruce for the project. Initially we had wanted to scarph a new timber top onto the original mast though now thirty years old still in excellent condition. Harry Spencer visited Cambria in Cannes that October to carry out a mast survey and discuss ideas. It was a memorable sight. Harry at 79 years of age in the bosun chair taking core samples in a torrential autumn rain 40m off the deck! Following a particularly memorable weekend with Harry we still favoured scarphing old to new, similarly as Harry had previously done with Creole. We also discussed timber. At this time Cambria was moored next to Eleanora in the old port of Cannes. It was mentioned that should we require any further spruce to contact the supplier of the spruce used to build Eleanora's substantial rig. One phone call later to Touchwood BV and its proprietor (JLVB) a tree (sitka) in Alaska recently felled to make way for a road construction, was put aside for the project. Rough sawn 12m boards of 75mm thick up to 700mm wide of aircraft grade Alaskan sitka spruce. Such boards accommodated the initial design which was to follow as closely as possible to the old mast in cross section. By February of 2005, we had decided to use Touchwoods' Spruce because of its scantlings and following the kiln drying it would be available in March/April. Enough quantity was shipped to build a complete mast. Though the core survey was positive, we still wanted to get the old mast out and horizontal for a closer look before making the final decision.

Having chosen a yard to work with, Cambria headed for La Ciotat in April for further preparations. Classic Works is a relatively new yard within the old ship building facility in La Ciotat, on the south coast of France. A small group of local shipwrights and joiners with a passion for classic yachts fronted by Alex Laird and Butch Dalrymple Smith who certainly won favour by claiming Cambria to be the most beautiful of her era. Whether a shrewd business comment or not, the love for these yachts was soon apparent after talking with employees. Within days the old mast was out and stripped naked of all rigging and fittings. Harry again visited for a closer, somewhat dryer look. After much discussion we decided it would be more efficient to build a complete mast. This also had the advantage of a clean slate for Cambria - a mast for the next thirty years. By this stage the Spruce was being held by Dutch customs under threat of being burnt due to an overnight change in EU regulations, and the Yard was backing up with Spring work load. Whilst dealing with the obstacles Cambria was lifted and a number a past rumors and survey requirements were laid to rest. The crew completed a perfect topside paint job, praised by the resident painters. The end of April saw customs give the Spruce back, unsinged, and together with JLVB we hand selected the boards to become Cambria's mast. These boards, all individually named (!!), were selected on the following criteria; defect free (no or limited knots, shakes, sap pockets), clean straight grain with no run out and density (measured using sound resonance). Obviously in the largest size we could find. After sifting through approximately 30 m3 with the help of a couple of other Dutch barge spar builders (who were getting second choice) we had selected 15m3 in which was contained the 12 m3 we required. From sketches and initial drawings by H.S, Aurellien Lebas the Classic works naval architect completed the design and drawings of the mast. Devising a scarph plan so as to stagger the scarphs (of which there are 192 in the main structure), and utilize as much of the wood as possible minimizing wastage and off cuts was no easy task. The main difference to the eye with the new mast design is in its form from the top spreaders through the jumper fitting to the mast head. This was the carbon and carbon/wood join of the old mast. By taking a fair curve from below the old scarph to the mast head, the new masts form was drawn. By maintaining a wall thickness ratio of 20% of the masts diameter the structural strength is achieved.

The Spruce arrived in La Ciotat by early May, as we were now one month behind schedule the decision was made to return the old mast and get Cambria ready for cruising in August and the Autumn racing carnival in the Western Med. Other work being carried out by Classic Works such as a new bunk berth in keeping with Fife drawn by Theo Rye was installed in the guest cabin whilst the dog house, which had been removed to treat a water ingress issue, was carefully reinstated, following repairs to the original yellow pine deck.

Cutting out the jigsaw pieces to create the puzzle to build later was further food for thought. The design had the scantlings of each board which was also numbered and lettered. The rough sawn boards then had to be organized, labeled, cut and milled into planks to match. The philosophy behind the project has been to minimize waste of this beautiful timber, thus extra time was taken so as to limit the wastage which in projects like this can be 40%. At completion we had over 130 individual boards ready to be scarphed and glued together into 48m planks to form the structure of the mast. We used a 13:1 ratio for the scarphs.

Following the testing at the Delft University of different glues on the market including Epoxy and Resorcinol, we chose MUF (Melamine Urea Formaldehyde). Though the glue requires substantial pressure when clamping, for ease of use, weathering characteristics and open time (that time between spreading the glue on the two surfaces and closing them together) MUF is an excellent product. To use the glue correctly, as with most glues, a freshly planed surface is required. Thus before glueing, surfaces would be prepared to within a millimeter of the final dimension. The wood was also to be at no less than 15 degrees C ambient temperature to fulfill specifications. As the project had now become a winter exercise Classic Works built a 55mx5mx3m tent (tunnel), over 14 laser set trestles for our base reference, within which we could control the temperature. Once the temperature was correct and the surfaces freshly cut and cleaned the pieces were glued together!!

Following a magic season on the water, Cambria returned to La Ciotat mid-October. The tent was complete by the end of October and the process of joining over 130 individual planks into a mast begun. Using routers and scarph boxes set at 13:1 the surfaces were prepared. Glueing always occurred within 24 hrs of preparation and all prepared lumber was stored within the tent for the correct ambient temperature. The mast was to be built as a box - an aft face, two sides and a forward face. The largest scantlings of the mast are 600mm x 400mm. To organise and plan the process was Joacquim De Oliveira, head shipwright of the project. The project immediately captured Jo as it has with everyone who has been involved.

First the aft face was built. This required five 48m individual planks to be made, three to then be edge glued together, to form half of the required wall thickness. The other two are also edge glued together to form the other half of the wall thickness required. By building this way no glue joints are in line. Once the two halves are individually glued together the joining 48m face are then planed, cleaned and glued together to form the aft face; the straight face of the mast carrying the mast track. Locating dowels were positioned along the center line of the two faces to stop sliding when clamping. Clamps were placed at every 250mm, thus requiring 200 clamps for the procedure. This initial glue took 20 people; it was the only face we could physically manipulate.

The aft face, once cleaned up was the left as a reference point and fixed into position. Space was an issue as the next step was building the two sides, at their largest section over 600mm wide. These walls were composed of four individual 48m planks, which then once glued together had a triangular section (48m) glued to each internal edge. The triangles were to add surface area for gluing the box together. Once all six individual components of the side were completed, they could then be prepared for the solid and hollow sections of the mast. Cambria's mast is solid at points of load bearing lateral compression, ie at the mast head, spreaders, jumper, gooseneck, deck, and heel. Between is hollow so as to reduce the weight. The solid sections taper to the hollows so as to avoid any point loading, and each taper was carved out by adze and hand plane and painted. Over one m3 of off cuts was used to fill the solid sections. The taper of the masts front face was cut into the forward edge of the mast sides. To glue these two massive sections together, crane arms were built on every second trestle, each with a one tonne chain block. The two sides were glued together on top, but not to, the aft face. It is enough to glue two 48m sections weighing over a tonne each at once let alone three! Tape prevented the sides bonding to the base. Once the sides were together, they were lifted off the aft face which was then carved out in the hollow sections, planed and painted ready to have the sides glued on top. Once this was achieved, space was at hand to build the forward face of the mast. A similar method as the aft face was used. The last scarph was cut at the end of February, and the last clamp joining the completed box section together was early March.

Next; shaping and rounding: Following the construction of the mast in its rectangular form, the next challenge was shaping and rounding. As the sides had been built with taper, and the aft face is essentially straight, the shaping involved, before rounding, was to remove excess wall thickness in the forward face. The wall thickness is reduced so as to reduce weight aloft. Thus wall thickness decreases from 120mm to 60mm. The majority of the timber was removed using power planers to within 1mm, then finished by hand plane. Tapers were marked out using the aft face as a reference and then twelve meter plywood straight edges to fair in the line. With the mast now square and all final dimensions within the square it was time to start rounding. After much discussion with spar gauges, both 8 and 16 sided gauges, we decided to use the same proportions but with a custom made gauge with one marker.

With lines marking out the timber to remove, two of the team would drive a 14 inch circular saw, one pushing and one pulling, along the 48m length. This was within 5mm with the remainder taken off with the power plane, and then hand plane. The forward face was first, once we had achieved 14 sides the remainder of the face was done by eye. With as much hand planning as possible achieved the remainder of rounding was completed using 2m torture boards and starting at 40 grit paper, through 60, 80 120 to 150 grit paper. Once the forward face (other than final sanding for coating) was finished, the mast was turned over to round off the aft face. As no taper is cut on this face we could start immediately to mark out for rounding. However, as the forward face is now tapered and curved, new supports were constructed so as to keep the aft face straight once turned. Rotating the mast was achieved using chain blocks, attached to a steel girder running the length of the roof above the tent. Once turned and checked the circular saw was soon out lopping off the sides at 45 degrees, again to within 5mm. Following the same process we rounded the aft face with the exception of leaving a 42m straight flat for the mast track. With the exception of the Jumper fitting we have reused all fittings from the old mast, including the mast track. Thus the dimensions had to be accurate to accommodate all the through bolts and curves and angles. The fittings, including the spreader cheeks, have now all been fitted and the construction of the mast is complete. We have oiled the mast for protection. Rigging is also now complete and pending weather the mast will be stepped on Wednesday 19th of April in the dry dock at the Chantier Naval in La Ciotat. This marks the end of a busy, challenging and rewarding winter for Cambria and her crew. The opening regatta for us will be the 'Voiles d'Antibes' at the end of May, prior to that Cambria will be sea trialing in the bay of Cannes.

Back to news