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The 55' Pelagic Voyager
"VALKYRIE"
Copyright 2012 - 2019 Michael Kasten
Perspective Aft | Perspective Side | Perspective Forward
Rendering Aft | Rendering Side | Rendering Forward
Five Designs - Common Characteristics...
As with the 30' Ernest Shackelton, the 33' Freyja, the 44' Valhalla, and the 66' Asgard designs, the inspiration for this vessel was drawn from Viking craft, as well as from Coast Guard surf boats and Whaleboats, all of which were double ended in their original form for maximum seaworthiness.
One whaleboat in particular, the James Caird was purpose-built for Ernest Shackelton to take along on the Antarctic voyage on which his ship Endurance was crushed by the ice. The whaleboat allowed Shackelton to sail from Elephant Island at the north end of the Antarctic Peninsula where his crew were marooned, to South Georgia Island where a whaling camp was known to exist, more than 800 miles distant. Shackelton's voyage in the whaleboat James Caird was one of the greatest sea voyages of all time.
The VALKYRIE design shown here at 55 feet on deck (16.8 m) is much larger than the James Caird. But in keeping with the smaller 30' Ernest Shackelton design, a simple structure is used so that the vessel can be built economically. The goal has been to create an easy to build, affordable, easy to sail and easy to inhabit boat, but at the same time one that can be used in extreme seas in order to allow worldwide cruising in complete safety.
Being a double ended boat there is perfect balance when heeled. In other words, unlike a transom stern boat on which the heeled centerline shifts to leeward at the stern, with a double ended boat the centerline stays on center when heeled. On a transom stern boat, when rolling the shift of the CL astern (but not at the bow) induces yaw, which results in difficult steering control. By contrast, the inherent balance provided by a double ended hull shape does not induce any added yaw, therefore providing greater steering stability, and much less weather helm under sail.
Having a flush deck at each end provides the ultimate in seaworthiness. This is the same configuration used by the original Coast Guard life boats which were intended for rescue work in extreme conditions. The raised fore and aft decks provide the maximum reserve buoyancy in the ends, and add considerably to the righting moment in a knockdown. The cockpit being just aft of amidships offers the maximum protection from boarding seas.
In all, the 55' VALKYRIE is reminiscent of Herreshoff's 55' MARCO POLO. Though by comparison the Herreshoff design is extremely narrow (10 feet!!) it is also much deeper - a necessary consequence of having such narrow beam in order to carry her sail. Despite those differences, Herreshoff rightly selected the double ended hull form and "whale back" flush decks at each end for his own "most seaworthy" pelagic yacht design.
Click for Larger ImageThe all aluminum structure planned for the VALKYRIE 55 provides an extremely rugged hull as well as light weight, allowing the structure to be fully welded and completely water tight. At 55 feet on deck, headroom is able to be a full seven feet throughout. The keel is fairly low aspect, allowing safety when grounding - intentionally or otherwise - and expanding the cruising grounds considerably.
The waterline length is 46.7 feet (14.2 m) taken as the length of the canoe body of the hull - not including the stem or the stern part of the keel deadwood beyond that. Draft is 5 feet to the Reference WL, allowing easy navigation anywhere outside the one fathom line. Beam is 15.6 feet. Target displacement is approximately 56,834 pounds light ( 25.8 m.t.) and 65,000 pounds loaded.
The Displacement to Length Ratio is 249 at the Reference WL, indicating a light and easily driven hull. Sail area is planned to be 1,900 square feet (177 sq. m.), with another 500 sq. ft. planned between a larger genoa, and a modest mizzen stays'l (or Fisherman Sail in the case of being rigged as a schooner).
Typical displacement hull speed is considered to be 9.2 knots for this vessel as a function of the WL length, however with the rather light D/L Ratio the VALKYRIE 55 is expected to easily reach 10.1 knots under sail, with 11 knots likely to be sustained while sailing down wind with a following sea. Believe me, 26-some tons of boat blasting along at 11 knots under sail definitely *is* something to write home about...!!
Interior
The framing is arranged in modules of 56 inches, which conveniently allows for flexibility with the interior layout. There are four aluminum bulkheads, one at each end of the center cockpit, enclosing the engine room below, and one at each end to enclose the forepeak and the lazarette / after peak. With four bulkheads and only six frames, construction is made as simple as possible.
The interior has been planned to allow two couples to live onboard in comfort, with their cabins as equal as possible. In addition, there are sleeping spaces for four guests using the two saloon pilot settees and the cockpit seats - in other words, sleeping for eight in all. Now, no one is likely to want that many onboard for more than a weekend camping adventure, but there is space for it..!
Click for Larger ImageFollowing the drawing above, we observe two sleeping cabins, one located in each end. The two private suites are nearly identical at 14 feet in length for each. They include a head / shower compartment and writing desk / office / computer station. Just forward of the cockpit, the galley is located to port and spans a length of 4' - 8" arranged in an "L" shape.
To starb'd of the galley there is a navigation station aft just forward of the cockpit bulkhead.
Just forward of the galley is the saloon, at 7' - 0" in length. The concept here is to have a settee / couch on each side, with a low coffee table in between. Outboard of the settees it would be possible to arrange a pair of pilot berths.
The amidships cockpit is 9' - 4" in length. Arranged with a long settee / berth on each side, there is ample seating for everyone onboard. With a table on center that can be extended, it makes a good outdoor entertainment / dining area. It is also a functional cockpit, having a binnacle and wheel steering, with easy access to sheets and halyards. A canvas awning over the center cockpit area would be easy to arrange in order to provide shelter from rain and sun. Alternately, a hard dodger could be arranged for better shelter from the elements.
Below the cockpit seats on each side are a pair of rather enormous storage lockers for deck gear, fenders, spare line, dock lines, and the like. Outboard of the seat-backs is a side deck - a convenient place to step aboard, and a good place to keep sheets and other lines from invading the cockpit itself.
Mechanical Space
Below the cockpit is a large engine room, having fuel tanks outboard and a bench seat along each side just inboard of the tank face. This makes engine maintenance easy from a seated position on both sides. The cockpit sole structure extends out to the side of the hull, and the large integral tanks are located below that continuous deck. Thus, the tanks extend from the cockpit sole to the hull bottom the full length between bulkheads outboard.
The engine is planned to be a 6 cylinder John Deere 6068 TFM marine diesel with a standard reversing marine gear driving a Nogva pitch control Servo. A three blade Controllable Pitch Propeller is specified, allowing full feathering during sailing.
Rig
A simple Bermuda Ketch rig is shown in the above interior profile, however in the rendered images in the above links, a Bermuda Schooner rig is shown. The spars are aluminum Schedule 40 pipe, which is considerably stronger than wood, and it does not rot! Pipe has sufficient wall thickness to allow the fittings to be fully welded in place. This whole affair is very easy to build and there is far less maintenance than would be required for a wooden mast.
The objective in general is to have the rig be as simple as possible, to have low stress in all components, and to have most of the sails be self-tending so there is no drama in tacking. The Bermuda rig as shown lends itself rather well to use of wishbone booms, which serve to keep the sails perfectly trimmed regardless of their angle to the wind. A wishbone is also conducive to the use of roller furling along the luff of both main and mizzen.
The Concept
Having been originally modeled after the very capable Viking craft somewhat in the vein of Shackelton's whaleboat, we have the makings of a truly pelagic vessel - one that perfectly illustrates my ideal Nomadic Watercraft.
Other Designs In This Series
30' Ernest Shackelton | 33' Freyja | 44' Valhalla | 55' Valkyrie | 66' Asgard | 78' Schooner ODIN
Please see the AVAILABLE BOAT PLANS web page.
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