Deck Progress on the Expedition Cruiser.

Last month I introduced the aluminium expedition cruiser that is being built by John Dearden in British Columbia. At that stage the hull had just been turned upright. Now the cabin is taking shape and the cockpit has been started. I will let the photos and captions explain the boat.

How she will when look heeled over under sail. The very sleek bow will present little resistance to water flow. A colleague has said that her bow will peel veneers off the logs that she encounters. John Dearden has done a nice job of building fair lines with our experimental chine detail.

John Dearden working on the small trunk cabin. Ahead of this is a sunken foredeck with hinged hatch to an anchor locker. The sheer is trimmed all around with a pipe to soften the edges and to form a catchment area for rainwater.

View along the cockpit, with the side decks installed. On centreline there is a trench full length of the cockpit, with a perforated plate over it. This trench is open to the top of the swing keel casing and aft into the outboard engine well, providing copious drainage in the event of taking a large amount of water into the cockpit.

The aft end of the cabin is sloped for comfortable lounging under the partial protection of the dodger when under sail or anchored. It also gives room for the forward oarsmen to pull a full stroke without colliding with the cabin. The forward rowing thwart (there are 4 each side) is starting to take shape aft of the cabin.

General Arrangement drawing, showing cockpit layout, interior and the swing keel.

Watch this blog for more about this project. To see more of our other designs, go to our main website or our mobile website.

Aluminium Expedition Cruiser

I am working on an interesting commission, have been for a few months and it is nearing the end of the design work. The boat is being built in Gibsons on the gorgeous Sunshine Coast in British Columbia, Canada. This is the first metal design commission that I have had in a long time, with metal boatbuilding being in somewhat of an hiatus for a few years. That part of the world has a massive logging industry, with logs floated downstream in the rivers in huge rafts. Logs are like cattle being herded to market by cowboys; occasionally one or two get away from the herd.

In the case of wayward logs, they can drift around for a long time before going ashore on a beach, where they become handy seats on which to picnic with the family. Until they are washed ashore they are navigation hazards for boats, particularly when they become deadheads i.e. floating vertically. In that position they present very little above the water to be spotted from a boat but they have tremendous inertia, capable of doing substantial damage to a boat that collides with them. It is no surprise then, that aluminium boats are more popular in logging waters than elsewhere. They have more chance of bouncing off the log with no more than a dent that could fracture a fibreglass or wooden hull.

Owner Tom McPherson with his aluminium hull

This new boat was commissioned by Tom McPherson for adventure cruises in the protected waters between the mainland and Vancouver Island. Although these cruising waters are protected from Pacific Ocean swells by the 285 mile long island, the channels and fjords are well-known for strong currents and eddies. Thick fog is also very common, so careful navigation and attention to obstructions and depths is necessary to stay safe.

The intended customers for the adventure cruises will be teenagers, learning about the wilderness through which they will be moving, the creatures that inhabit it both on land and in the water, and the flora of the dense forests. Man is doing so much to mess up the beautiful blue marble on which we hurtle through space, so teaching the next generation about stewardship of the wilds and our fragile world is an important issue.

This is not just a holiday cruise for the young crew; they will learn the skills of boating and earn their way with aching limbs and calloused or blistered hands. With only a small outboard motor for propulsion into and out of harbour the crew will sail her some of the time and row her at other times. She has thwarts for 8 rowing positions. This is no luxury cruise, the crew will sleep in the large cockpit under the stars or a cockpit tent when needed. There is a small cabin in the bows, with a pair of V-berths, galley and enclosed heads.

For stability and windward ability, she has a ballasted swing keel. The cockpit has a long covered channel full-length, draining through the keel casing and outboard engine well.

This boat has to be able to carry a relatively large live load of 10 teenagers plus two adult crew, in addition to stores (which can be replenished as needed by occasional stops along the way). There is a benefit derived from the live load, of course, of considerable portable ballast that can be moved around the boat for best trim and stability.

With the intended use of gliding along with minimal disturbance among and past the wild animals of this wilderness, a boat of easy lines was needed, one that creates minimal waves and is very easily-driven under oar power. For sailing, she has a gaff schooner rig that can carry a reasonable spread of canvas with a low centre of effort, very versatile in a range of sail combinations to optimise area and helm balance to suit wind conditions. The spars are sealed carbon tubes in tabernacles, easy to raise and lower. The boat is legal towing width for transport on land, so the masts can be folded down horizontal and left in their tabernacles to simplify the process.

Gaff schooner rig, carbon tube masts folding down on tabernacles.

The hull is a big sister to my Cape series of designs that started with the Cape Cutter 19 and has spread over the years up to 32ft. But those are beamy boats and this one has been stretched out to give the slim and easily driven hull needed for her intended use. It results in a boat of very graceful lines and proportions, with fine, hollow bow at waterline and clean stern. She will slip through the water easily under sail or oars.

Slim, sleek, easily-driven hull with fine bow and clean stern.

Yes, the Cape designs all have lapstrake plywood hulls. This new boat (we really must give the design a name) has the lapstrake shape but done in aluminium. To get that right, I was pleased to be working with an experienced builder with whom to figure the best way to get the shape needed, without distorting the hull plating from excessive welding. John Dearden is that builder, having built the aluminium centre cockpit Dix 43 "Namo" as a custom build for her owners about a decade ago.

Owner Tom is working with John Dearden on the build. They turned the hull over a few days ago and report that it has turned out fair and is very pretty. Planned to be in service in the coming season, the launch is targeted for March.

Turning the hull happened a few days ago.

Tom McPherson shows the project and his cruising grounds on Instagram at Seaforth Expeditions. He has photos and time-lapse videos of the turn-over and videos of his cruising grounds.

Aluminium Boatbuilding

This post was prompted by me receiving the photo below from a client who is building one of my aluminium designs. I have posted about him before, his name is Brian Russell and he is building in Tennessee. The reason for the post? Well, the photo is just so gorgeous in its composition and shows up the framing system of the boat so nicely. And, of course, there is his pretty wife right in the middle of it as well, to add interest.

Brian Russell's Dix 43 Pilot. The black surfaces are

insulation, which highlight the framing system of

longitudinal stringers and transverse frames.

Brian is a professional sculptor, so he obviously does beautiful work and has a great eye for aesthetics to show it all off. Brian's website is at http://www.odysseyyachts.com/ .

This design is the Dix 43 Pilot, originally drawn for steel construction. Many have been built by professional and amateur builders from steel and a few have been built by professionals from aluminium. One of them, "Blue Pearl" was built by Jacobs Brothers in Cape Town and has cruised many thousands of miles, including voyages to both the Arctic and the Antarctic.

"Blue Pearl" in the Antarctic

Aluminium is a great boatbuilding material and well-proven in use. It is also a much nicer material with which to work than steel. It is relatively light, so it is easier to manhandle pieces by yourself than with steel, with less need for heavy-lifting equipment. It is also easily worked with woodworking machinery like power saws, power planes etc and it is a lot quieter to work than steel. It also has the advantage that it is not necessary to paint it above the waterline, so the increased cost of the material is offset to large extent by the savings in fairing and painting.

OK, so what is the problem with it that blocks most amateur builders from using it? Aluminium is a material that can result in an unsafe boat if the builder does not properly educate himself before starting construction. That education is needed in two areas, which are proper choice of alloys and correct welding techniques. Get these two things right and you will have a good boat.

Proper choice of alloys is important because incorrect alloys will result in corrosion problems that will seriously shorten the safe life of the boat. The aluminium must be marine grade, from the 5000 and 6000 series of alloys and they must be selected for their strength, welding and corrosion characteristics.

Correct welding technique is much more important for aluminium than for steel because it is a more difficult material to weld successfully. Correct preparation of the weld zone and cleanliness of the work area are needed because any contamination in the weld will adversely affect weld adhesion and strength. Aluminium welding is also badly affected if the inert gas is blown away, allowing oxidation of the molten metal. That means that there must be no wind or other air movement where the welding is going on.

So, any amateur who is prepared to take courses at the nearest Community College should be able to build a good boat in aluminium. You don't want to find out in 60 knots of wind and 50ft seas in the Southern Ocean that your welding techniques were not up to scratch. Do it right and you will have a boat that can take you anywhere in the world that you want to go.

See our full range of designs and much info on boatbuilding at http://dixdesign.com/.