Project Zebulun
Zebulun was the brain child of Loren Murphy after sailing as a missionary in the South Pacific starting in 1985. Over the past 20 years Loren has sailed over 42,000 nautical miles reaching over twenty countries and island nations. These experiences as a missionary and providing relief work were the catalyst for this project. Loren shared his ideas with Michael Kasten of Kasten Marine Design, Inc.
Zebulun was designed as a highly capable long range, fast and safe offshore sailing vessel in aluminum for sailing expeditions ranging from the tropics to the arctic. The original intent was that Zebulun be capable of doing rescue work, mission work, and relief supplies delivery for troubled areas. Long range under power was also a primary requirement, thus one could legitimately refer to this as a true motor-sailor, with 100% functionality in either mode. Zebulun's lines will provide high performance in an easily driven hull, planned for maximum speed and the fastest passage times. The twin keels and rudders allow her to sit down where there is a big range with the tides. The interior layout has been planned around an extended family, or a large charter party. As such, Zebulun will also make an exceptionally fine charter vessel.
Hull Particulars are as follows:
- 96' LOA
- 89' DWL
- 23' Beam
- 8' Draft (twin asymmetric bulb fin keels)
- 206,000 lb. Displacement at the DWL
- D/L 127
Displacement will vary from
around 195,000# when lightly loaded, to a maximum capacity of 259,000# with tanks full, stores for twenty
people, and the boat ready for a long passage, or alternately loaded with a cargo of supplies.
As we can see from the above data, Zebulun is of nearly 'ultra-light'
displacement. Hull speed is predicted to achieve nearly 18 knots.
Typical sailing speeds in favorable conditions should be in the range of
12 to 14 knots. In other words, built for comfort AND speed...!
Below are Popups to other aspects of the yacht.
Zebulun has been designed to exceed the scantling requirements of the ABS Rule for aluminum vessels, and therefore also meets the EU requirements for vessels of this size.
Interior materials have been chosen to be as light in weight as possible, while not being overly expensive to construct. For any of the larger flat panels where it will not increase the joinery labor to any appreciable degree, honeycomb panels are used. Exterior Layout Forward, the deck is surrounded by substantial bulwarks for maximum safety. Aft, the deck is surrounded by an ample toe rail for security when coming and going from the cockpit. Although not shown on the drawings, the decks are additionally protected by a 36" high welded bow pulpit, stern pulpit, welded stanchions and lifelines along both side decks. For additional safety there are welded aluminum hand rails along each house top.
A hard "Bimini" top is provided above the forward part of the cockpit, with windows opening forward. This was an originally requested design feature that works out rather nicely, however if a soft dodger were preferred - so be it...!
For anchor handling, a pair of hydraulic vertical axis windlasses are located forward, with stout mooring bitts located on either side of the foredeck. Additional mooring bitts are placed on both side decks and on the after deck, three per side. Additional smaller bitts and cleats are provided as needed.
Interior Layout The cabins have 6' 8" headroom throughout the main cabins - at the centerline. For the sake of headroom in the aft cabins, the exterior deck aft is raised to the height of the top of the main bulwark. Where needed, headroom pockets have been created within the cockpit structures to permit standing headroom in the aft master and guest cabins.The accommodations aboard Zebulun have been designed to provide comfortable living for two to six crew aft, plus twelve or more passengers forward during extended passages.
A large "Great Room" is located amidships for the purpose of comfortable lounging for passengers and crew; for the purpose of carrying more day-passengers on shorter voyages; and for stowage of cargo when desired. The layout could easily be changed to suit a newly defined purpose. If an alternate layout for fewer passengers were preferred, the guest cabins could be expanded in size, making four generous guest cabins, each with their own en-suite head and shower. Or if so desired the amidships lounge could be differently configured. The Zebulun is really quite large so the possibilities are many.
Layout Alternatives Ownership Options... The interior layout allows the vessel to be used in several modes:
- As a personal world-traveling yacht for a private owner and family or guests, or
- For use as a charter yacht with "managed ownership."
By "managed ownership" we mean that the yacht is privately owned, but is managed by a charter company who is able to charter the vessel when it is not being used by the owner. In exchange for its use, the charter company takes care of the vessel's maintenance and repairs, and provides the owner with an income stream. Done correctly, this is a rather ideal way to own a boat - no maintenance, it pays its own way, and the owner can step aboard a well maintained vessel nearly any time and simply enjoy their time aboard rather than having to manage the vessel's upkeep. Power & Range The engine space, located below the Pilot House, is thoroughly sound proofed, and has a forced ventilation system. Low levels of noise and vibration are provided via adequate sound insulation and vibration damping. There are flexible engine mounts and a flexible coupling on the shaft.
There are two fresh water cooled Cummins 6CTA 8.3-M marine diesel propulsion engines. Using a continuous duty Marine rating, the engines provide 285 hp each at 1,800 rpm. Autoprop propellers are used. Shaft rotations are opposite. Long range cruising speed for this vessel is between 10 and 11 knots. Per the typical Beebe method of calculating average range in ocean conditions, range is approximately as follows:
- At 10 knots, range should be around 4,700 NM.
- At 11 knots, range should be around 3,500 NM.
- At 12 knots, range should be around 2,200 NM.
Displacement hull speed per the traditionally applied speed to length ratio of 1.34 is around 13 knots. However due to the very light displacement to length ratio, using the above engine horsepower, the calculated maximum speed should be around 14 knots under power alone. Maximum achievable speed while motor sailing is likely to be around 17 knots, or given the right conditions 17 knots should be possible under sail alone. The Rig Zebulun is given a three masted schooner rig in order to make use of relatively high aspect individual sails, while keeping the rig to a conservative height overall, and individual sail sizes within manageable limits. Sails are fully battened to enable the use of a large roach and an elliptical plan form, while still allowing maximum draft control. The two forward sails are identical in size and construction, and the mizzen slightly smaller.
The sails are each cut differently in terms of draft in order to take maximum advantage of their relative positions in the rig. There is one large roller furling jib on an inner forestay, and there are two other light weather stays'ls set from the respective mastheads. Standing Rig The masts are each identical in terms of their layout, with the exception of the amount of bury belowdecks, and with the exception of the height of the mizzen boom. The masts and booms are constructed of 6061 T-6 aluminum pipe. All spars are welded shut in order to be air and water tight. Halyards are external. Reefing is slab type with hydraulic winch assist.
The rig is supported by swept back spreaders, making use of a single lower shroud, and a single upper shroud per mast per side. There are running backstays at least on the Mizzen mast (other locations to be determined.) Wire is 1 x 19 type 316 stainless throughout, except for the running backstays and the jib's internal luff wire, which is 7 x 19 type 316 stainless. Turnbuckles are one size larger than the wire they serve, and are fitted with toggles. Wire terminals are poured sockets throughout. Running Rigging & Deck Hardware All running rigging lines are pre stretched braided Dacron line. Blocks are by Harken or equal. Halyards terminate on belaying rails at the base of each mast. Sheets are led to the cockpit area. There are two halyard winches per mast, one on each side at a convenient height. There are three sheet winches per side per side to handle the jib and stays'ls. Sheet winches are located in the cockpit area. For the boom sheets, there are Harken or equal roller bearing travelers, arranged to be at the full available width. Sheets are located within the outer 20 percent of the booms. There is a downhaul at the gooseneck of each boom. Reefing gear is provided for two reefs in each of the sails attached to the masts. Mast hardware includes Harken roller bearing luff track and cars, Harken gooseneck, Harken roller furling gear for the jib, and Harken boom hardware. Sails The Foresail, Mainsail, and Mizzen are fully battened. They have a large roach and are loose footed. Headboards are provided, as drawn. Sail cloth is stabilized Dacron or better. Battens are solid round or rectangular GRP extrusions, sized to suit the loads. Battens are attached at the forward end to Harken cars designed for the batten loads. The Fore, Main and Mizzen each have two reefs. The jib is roller furling. A storm jib is provided. A genoa or cruising spinnaker may be provided (to be decided). A pair of light weather stays'ls will be flown from the Main and Mizzen mastheads, set flying and attached at the deck to weather of the next forward mast.