Entries | Portfolio

Beach Cruiser - Reloaded

The Beach Cruiser sketch from last March has progressed into a 3D model - my first 3D project in a long while - a good vehicle for relearning the ropes. To recap, Beach Cruiser is intended to be a multihull version of the popular "open boat" style of camping cruiser. Over the years, small cats have become somewhat the victims of their own success - evolving into pure race boats. It's a bit of a shame really, considering their roots come from the ocean crossing voyaging canoes of the Polynesians. Why not a beach cat "voyaging canoe"? A small trailer boat that maintains (much) of the performance of its race bred cousins, but with considerably more storage, comfort and seaworthiness. A boat for really going places... quickly!

continued...

Old School

Beach cruisers are single gear bicycles with upright posture and balloon tires that put more emphasis on ride comfort and style than ultimate performance - the alternative to the ubiquitous road and mountain bikes. In that spirit, I present Beach Cruiser, the alternative beach cat. 19' LOA by 8'-6" beam, Beach Cruiser fits nicely on any beach cat trailer. The sail area of 220 sq. ft. also means that any beach cat rig can become a suitable power plant. However, that is where the similarity to the usual beach cat ends.

I found inspiration in the 1960's design work of C/S/K - the California based team responsible for classics like Aikane, Patty Cat II and Polycon. Beach Cruiser has narrow and boardless asymmetrical hulls, which while not the ultimate in efficiency, are beach friendly, and these deep and narrow hulls also deliver a terrific ride. The hulls taper into integrated rudders at the stern that should leave a clean wake and equally important, gains style points. The reverse sheerline sweeps forward to wave cutter bows, giving a nod to the Polynesian roots of the craft, and of course, everyone onboard wears Aloha shirts and boardshorts.

Beach Cruiser has actual raised seating and a solid bridgedeck between, which will make it an order of magnitude more comfortable than the typical beach cat. The wing area forward of the main beam will help keep spray down, as will the high 18" bridgedeck clearance.

The seats have big hatches to access the storage lazarettes in each hull, with more storage fwd of the main beam. Plenty of room for everything a beach cruiser could need (including tiki torches) with enough space to sleep a couple under a boom tent in the cockpit. Hang loose!

Rozinante II

A considerable amount of credit/blame for my love of small boats goes to L. Francis Herreshoff and his book 'The Compleat Cruiser'. I fell in love with his ideas about a simple yet refined cruising lifestyle, epitomized by Mr. Weldon and his whaleboat type ketch - Rozinante. Rozinante is beautiful, fast, seaworthy and handy, and I was musing recently about how a proa version of Rozinante might work out.

Rozinante Il is a mono-proa - a bilaterally asymmetric monohull. Her dimensions, style and intent are all within the ballpark of the original. She's the Rozinante from the alternative proa-centered universe.



LOA: 28' | LWL: 25' | BOA: 6'-10" | Draft: 2'-10" | SA: 285 sq. ft.

She's a lugsail schooner, which gives us a well-balanced rig that is easily handled, reefed and shunted, and the character is in keeping with the small gaffs of the original ketch. The cockpit is 8' long and deep enough for comfortable seating, yet the floor is above the waterline which allows it to be self bailing (unlike the original). Also unlike the original, Rozy II does not have a weighted keel and her draft is 8" less, though the keel is still sharp and deep for good windward ability. Rozy II's ballast is in the form of a water ballast tank to windward, beneath the cockpit seat.



Rozinante II's most startling feature is the pronounced hull asymmetry. It looks daft, but there's good reason for it. A traditional monohull's waterplane becomes more asymmetrical the more it heels, with the lee side bulging out, creating wave drag and a weather helm, usually counteracted by a large rudder (creating more drag). Rozy II follows the Micronesian practice of keeping the "flat" side to leeward, which creates a leeward turning force (and balancing the windward turning force of the schooner rig). The flatter lines create less drag, and best of all, the waterplane shape becomes increasingly symmetrical as the boat heels, not less. Heeled to 14 degrees, the yacht's waterline beam shrinks from 53" to 44", yielding a 7.6:1 Length:Beam ratio. I expect considerably better speed from this finer and much lighter Rozinante when compared to the original.



Accommodations are spartan below, as was the original. A single berth with sitting headroom and storage locker in one end, and an enclosed head in the other. Though L. Francis would prefer a cedar bucket, I'm including a marine toilet and holding tank as a concession to modernity. The galley box is in the cockpit, running the length of the leeward side.

Rozy II is steered via trimming the sheets and adjusting the two centerplate "trim tabs". In this, she follows the practice of Yakaboo, the record breaking sailing canoe of Frederick "Fritz" Fenger. She won't be "multihull" fast, but I think she'd make for a fun and rewarding boat to sail, and the looks she would get at the dock would be absolutely priceless.

Note: This is a sketch, a cartoon only. No plans are available.

Changeup

The slider is the best pitch in baseball. --Ted Williams

Changeup is a riff on Ray Aldridge's brilliant beach cruising cat, Slider. I hesitated to publish these drawings at first, since they are an obvious take-off on Ray's design, but imitation is the sincerest form of flattery, so I hope Ray takes them in the spirit intended, which is one of respectful admiration.

Slider answers almost every single desire of my beach cruiser fantasy: Twin hulls, shoal draft, simplicity, dock-like stability, ease of launching, usable space, cargo capacity, sailorman rig, and an aesthetic that reaches deeper than the latest multihull fad. The only problem - and this is ONLY a problem for my testosterone/adrenalin driven ego - is that it tops out at 7 knots.

OK, I admit I want it all - a beach cruiser that will outshine the Mona Lisa and outpace the Enterprise. But given my economic and scientific station, breaking warp (knot) 12 would suffice. The only way I can see to break that barrier is to get the whole crew behind the initiative, so when the breeze kicks up, all hands to windward!

Changeup is designed to accommodate both crew in the windward hull, when conditions merit. The idea is that sailing in light air (the predominant condition in my sailing range) will see each of the twin crew within their respective hulls. But if and when the need for speed arises, then both bodies may be accommodated in the windward cockpit, thus providing the potential energy required.

The rig is the sliding gunter w/ curved gaff, a scaled-down version of Manu Kai. Mast height is a manageable 19', and the 190 sq. ft. rig may contain up to three reef points.

The hulls are asymmetrical, and happily do without boards. Leeway resistance is provided by the hard chines, enhanced by chine-runners (see Matt Layden's Paradox and Bernard Kohler's KD860). The asymmetrical hulls position the buoyancy as far outboard as possible, gaining a few more inches of righting moment, and with a beam limited catamaran, every inch counts.

Changeup is 8'-6" wide, which is the only choice for a small boat that expects to be kept on a trailer - and used often. That said, I might be tempted to make a pair of 10' beams to fit when the boat goes for a cruise of a week or more. The extra trouble would be worth it.

Teh Pookie

Tepukai are singularly amazing proas from the Santa Cruz Islands that take the usual South Pacific parsimony with building materials to the nth degree. The boats stretch out over the water’s surface like a gigantic water spider, covering the most area with the minimum mass. Tepukai employ slender, submersible wave-piercing hulls, centrally located mass for low pitching moments, and excellent bridge deck clearance - all very M3K (millennium three thousand).

Jim Shanahan approached me with an idea for a tepuke inspired beach cruiser, and Pookie is the result. The boat stretches itself out to a 28’ LOA x 15’ beam, without weighing much more than a Hobie Cat. In the Oceanic tradition, the boat is made mostly of woven materials: Polyester, Nylon, carbon fiber, Kevlar and Spectra.

The basic configuration is a carbon fiber space frame which supports inflatable tube hulls, trampoline deck, shelter and rig. When folded and deflated, the contraption fits inside a 4’ x 8’ x 14’ box - a sailing version of George Jetson’s flying car in a briefcase.

continued...

Samwise - Part 3

Some fairly dramatic changes since Samwise Part 2 (Part 1 is here). The biggest change is that Sam is now a balls out Atlantic proa - rig placed in the windward hull. No faux Pacific, "weight to windward" sham, an Atlantic proa is Sam I am. Larger pics after the jump.

continued...

Samwise - Part 2

I fleshed out a few scale drawings of Samwise last week. In keeping with the minimalist theme, I'm doing the minimum of calculations. As you can see, proportions have altered a bit - but form follows function. The goal was to make the hull sides from straight ripped ply - 2' wide - easy as pie. The straight ply goal meant the crossbeams buried in the hulls had to go, so now they're lashed or bolted to the deck in beach cat style. The cabin has comfortable sitting/laying about headroom, 2' beam on the bottom. I'm debating whether I need a solid cabin or not. I could see small dodgers fore and aft, and making him into an open sailing canoe.

Still no rudders, as you can see. I'm quite certain the boat will self-steer as if on rails on most courses, and it would be fun to steer the boat by sail trim alone, and no rudders would save a lot of building time and trouble, but still... rudders are nice.

My enthusiasm for the lug rig has not abated. Masts are only 17' long! Read more about standing lugs in this Duckworks article by Michael Storer.


LOA: 24'
Length lee hull: 24'
Length windward hull: 20'

BOA: 12'
Beam lee hull: 1'-8"
Beam windward hull: 2'-8"
Interior headroom: 3'-6"

SA: 220 sq. ft.
Rig Height: 22'-8"

Samwise - There and Back Again

Samwise is a minimalist cruising proa, which is really the only kind of proa there should be, IMHO. The only thing not minimal is the performance - the proa’s raison d'etre. The basic idea is reliable and cozy camp cruising in the Pacific NW - where the water is generally frigid and the air is generally tolerable.

Sam’s godfathers include Matt Layden's Paradox and Rob Denney's Harry, while a host of uncles include Phil Bolger, Peter Spronk, Dick Newick and Ralph Munroe. He (all proas are masculine) features simple plywood construction, an enclosed sailing cockpit, plenty of deck space, endless conversations at the dock, and the ability to go there and back again.



The crew helms from an enclosed sailing cabin - which is a nice feature in the Pacific NW and its nearly iceberg laden waters. Laugh at the freezing spray as you drive like an arrow to windward! Mock the waves as they surge impotently against your plexiglass shielding! Unlike tacking craft, proa crew have no need to make the treacherous trek to the other side with every tack. You are always on the good side of a proa.

In the unlikely event of pleasant sailing weather, you can slide open the hatches, or sit atop the flat cabin top, or even sprawl out on the trampoline, catching the sun. The tramp will also make a fine place to pitch a tent for overnighting - if a real double berth is required.

The leeward hull is the load bearer, so it stretches out to 24' of lean, wake-cutting form. The windward hull is the ballast, which makes do with 18' of LWL. Skilled sailors will fly the windward hull at every opportunity. Being flat-bottomed in sharpie style, the hope is that it will plane if given half the chance.

The free-standing schooner rig makes for a criminally low center of effort, while the standing lugs create a powerful yet balanced, easily handled sail that requires no purchase on the sheets - which comes in handy during a shunt. The forward lug is rigged with the mast to windward (its most aerodynamically advantageous position) while the aft lug is set opposite, which moves the combined CE well forward (a desirable thing on a proa).

Leeway is prevented by a central, pivoting leeboard mounted on the leeward hull, and steerage is provided by fore and aft "dagger" rudders. The hope is that in the unfortunate event of a grounding, the deep leeboard will hit first, pivoting gently out of harms way as it stops the boat, whilst leaving the delicate rudder intact. As usual with proa designs, the rudders are sketchy... at best. From model testing, I found a schooner rigged proa such as this will balance and self-steer on most courses by sail trim alone - Sam, by nature, is a virtuous course keeper. Be that as it may, a real cruising boat needs a real rudder. Suggestions are welcome.

The proa's beam is retracted to trailer width via telescoping aluminum beams (as an option, Jim Shanahan has proposed an ingenious hinging mechanism).

Note: This sketch is a cartoon only. No plans are available.

QueeQueg 18

Indian summer is officially over around here, and thoughts turn to winter projects in the workshop. I've worked up a little trimaran design, inspired by Solway Dory's Osprey and Chris Ostlind's XCR.

It's an 18' stitch and glue plywood, 5 panel hull, with tortured ply amas and aluminum akas. Hull beam is 30". sail area: 118 sq. ft. a high aspect leeboard would be included (not shown). It would be fun to day sail, and might make a good little camp cruiser.

continued...

Hawaiian Sailing Canoe Rig

I've been on the Holopuni site many times, admiring their OC3 sailing canoes. These 30' canoes are wonderful examples of efficient paddle/sail craft, but still, I can't help meddle with an already good thing.

See, I'm anticipating the next step in sail area/performance upgrades. The Holopuni carries just 100 sq. ft. of sail, which is no doubt plenty for Hawaiian waters, and it is a safe and sane amount for a dual-purpose sail/paddle craft. But what about unsafe and insane sailing?

continued...

Page 1 of 2 pages  1 2 >