A 42' Ketch For Voyaging
"ZEPHYR"
Larger Sail Plan Image | Interior Profile & Plan
Side Perspective | Aft Perspective | Starb'd Above PerspectiveCopyright 1996 - 2010 Michael Kasten
The Concept
The Zephyr design is based on the excellent yachts from the mid 1900's. These yachts are not just elegant, sleek and graceful, they have the kind of hull form that behaves well at sea. For blue water travel they are comfortable, safe, fast, and weatherly. Zephyr has the attributes of sleekness, grace and speed, as well as a hull form that will stand up to a press of sail for windward sailing.
Design Details
Zephyr is a medium displacement spoon-bow, counter-stern ketch having a well balanced combination of beam and depth with a long fine run for fast open ocean sailing. The sail plan shown above has been recently updated in order to provide a larger sail area with higher aspect ratio sails. With the addition of a mizzen staysail for light airs, performance will be excellent in all weathers.
Principle dimensions are:
IMPERIAL DIMENSIONS
- Length on Deck: 42' - 0"
- Beam: 12' - 2"
- Draft: 5' - 4"
- DWL Displacement: 26,370 lb.
- D/L 323
- Working Sail Area: 1,015 SF
- Light Weather SA: 1,241 SF
METRIC DIMENSIONS
- Length on Deck: 12.8m
- Beam: 3.72m
- Draft: 1.63m
- DWL Displacement: 11,958 kg.
- Metric L/D: 4.46
- Working Sail Area: 94 Sq Meters
- Light Weather SA: 115 Sq Meters
Conceived primarily for ocean voyaging, steel construction has been chosen for its incredible strength and abrasion resistance. The single chine hull form was chosen on the basis of its simplicity, economy of construction, performance, and in order to blend well with the classic aesthetics of the design.
The swept back full keel provides excellent tracking at sea, and the NACA foil shape provides the best combination of lift and low drag for windward sailing. The rake of the forefoot and the "drag" to the keel bottom are the key elements that provide excellent steering stability. With this type of keel, the boat will not require a steering vane and can instead use a simple sheet to tiller steering arrangement. The keel profile can be seen here, and is the same as that of Highland Lass II.
The after-deck is raised in order to provide more storage in the lazarette as well as more leg room for quarter berths. A key benefit to the raised afterdeck is increased reserve buoyancy aft, thus a dry area for the helm and enhanced stability. The long aluminum davits are for carrying the skiff during day-sails, and for hoisting up at night to keep the skiff from being any trouble. For longer trips in open water, the skiff is lifted aboard using the mains'l halyard and nested onto the cabin top.
The Interior
The interior layout is the same as that of the 42' schooner Highland Lass II. With Highland Lass' schooner rig, the mast positions have largely determined what's possible with the interior. Therefore, in the forepeak there is a good sized chain locker. Aft of that, a settee is located port and starb'd and a table is hung on the mast. Just aft of the settee, a large galley is located port and starb'd. A ft of the galley there is a head to starb'd and a chart table / hanging locker to port. Two quarter berths are located right aft. The engine box is arranged to also serve as a bureau-top between the quarter berths. With this layout, one can sleep four when needed, and two in relative luxury.
An alternate layout would be quite similar to that of the 36' Grace. The main mast position on Zephyr would allow a generously sized double berth forward. Aft of that, to port and starb'd would be two 4.5' settees with a table between. If the settees were to be used for sleeping, it would be a simple matter to arrange a foot-well extending below the forward end of the galley counter.
Since Zephyr is much larger than the 36' Grace, there is quite a bit of extra length available for the rest of the interior. Given the excellent use of space provided by use of a pair of quarter berths aft, that is the ideal choice. As compared to Grace, all the remaining extra space amidships would be donated to having a slightly larger galley and a more generous head compartment to starb'd, and a combination hanging locker / chart desk opposite to port. In other words, the quarter berth, head and chart desk area would be the same as is designed for Highland Lass. This layout would allow comfortable sleeping for four on a regular basis, plus two additional guests on the settees.
The Rig
All the spars are made using aluminum pipe, with all fittings welded in place and all spars sealed at the ends so they are air-tight and will float. Aluminum is the strongest, the simplest to fabricate and the easiest to maintain of any spar material. If done nicely and painted, no one can tell that they are not made of wood!
The ketch rig works well for ocean cruising and provides a generous sail area, especially with the mizzen staysail - the "mule" as they say... Zephyr has a gaff mains'l in order to limit overall mast height and to provide an easily handled, robust, low-stress rig. The mizzen mast provides a good hand-hold when emerging from the companionway, and serves as the compass binnacle. An awning can be spread over the mizzen boom... a Bimini for the cockpit..!
The ketch rig provides quite a number of well-balanced sail combinations. The main and the stays'l when used alone have nearly the same balance as the whole sail plan, and will allow easy tacking in close quarters. With sufficient wind, the boat will also tack easily with only the mains'l set. Another equally well balanced combination is just the mizzen and the jib, say to keep the foredeck clear while stowing the ground tackle - an appropriate combination for getting under way from an anchorage.
One of the main benefits of the ketch rig as it is drawn is the manageable size of the individual sails. The mains'l is 398 sq. ft. and is well inboard where it can be handled safely and easily.
A sail plan option we have in mind for Zephyr includes a few additional sails for trade wind sailing in the form of a square sail and raffee hung from a cross-yard located just above the gaff saddle. The lower course and raffee would be set flying from the deck. These two sails are able to add a bit more than 500 sq. ft.
Summary
Zephyr was designed immediately following a rough and wet passage down the Pacific West Coast in the early 1990's. During that sail, the ideas for Zephyr came together in the form of several sketches, and were then worked into the design you see here. The features presented above emerged as the result of having wished for each one of them on that trip.
The result is, I think, excellent.
What would I change...? Not one thing really. But if desired, a Bermuda rigged main sail could easily be provided...
For more information about Zephyr, please inquire.
Please see the Plans List page to review our available Boat Plans.
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