Particulars are: 46' LOA x 40' LWL x 13'3" Beam x 5'4" Loaded Draft. Having a lightweight design displacement of 33,000# she is of "medium to light" weight, at D/L 255 lightly loaded. Displacement will vary from around 33,000# to a full load capacity of 43,600# with tanks full, and the boat ready for a voyage.
Hull construction is to be steel. The pilot house will be constructed with aluminum, and joined to the hull with a bi-metal strip, welded on both sides. Portlights and pilothouse windows will be Lexan, or tempered and laminated glass.
The hull is designed after the Pacific Northwest commercial fishing vessels, but with a much finer form. Prismatic has been optimized for the anticipated Speed / Length range. A fine entry, combined with a long graceful run aft will provide for an easily driven hull.
Deck structures have been kept low, to provide for a low center of gravity. With a conservative amount of beam, this will allow a comfortable motion, combined with an exceptional range of positive stability.
The arrangement is intended to provide comfortable cruising for two people, with the addition of a third crew member or couple for extended passages. The arrangement will also allow a skipper to charter the boat, while providing privacy for a couple as guests forward.
The chosen layout makes use of a long low forward cabin extending from right forward, to the aft-located wheel house. The cabin top extends the full width of the ship for its entire length, providing the greatest amount of interior space, the largest open deck area, the greatest forward freeboard and the most reserve stability.
Within the long forward cabin is the owner's stateroom, enclosing a double berth forward, with a bureau either side of the berth. On top of the bureaus, shelves run for the length of the cabin. Aft of the berth area are a desk / computer area to port, and a head / shower to starboard. At sea, the forward berth will be available, but not preferred. The forward berth will be able to be divided and a sleeper contained by an arrangement of bunk boards.
Aft of the owner's cabin, there is a pilot berth to port and to starb'd, each having a bench seat inboard, for use as a midship settee / salon area below. This midship location provides an easy motion for the pilot berths, as well as a more formal salon below decks for evening entertainment and for greater privacy.
Aft of the salon area to starb'd is the galley, and to port is the companionway passage up and aft into the pilot house.
On the centerline, inboard of the galley and the companionway, is a large engine box containing the propulsion engine. The engine box serves as a very large counter on the vessel centerline for use as a galley surface. The engine is located where it can be observed regularly, and tended easily. The engine box will be designed to have a highly effective "whisper pack" sound insulation, keeping interior noise to a very low level.
The wheel house will be aft of the galley / companion / engine area. The aft location provides the most comfortable motion for the piloting area, and the most safe location for the house structure. The house contains a wrap-around settee aft, a large piloting area forward and to starb'd, and the entry below to port. Exit doors lead out both sides of the wheel house forward, to access either side deck. There will be an ample chart desk / instrument area forward of the wheel, enclosed by the forward pilot house windows.
Aft of the house is a covered "cockpit" deck. At sea, the cockpit deck will serve as a protected fishing / observation area. In port, the cockpit may be enclosed by a screen, by a clear dodger, or by removable glazed panels. This will function as a "porch" whether at sea or in port.
Sailing skiff stowage will be on top of the pilot house. An outboard motor and gas cans will be stowed in the aft seat locker in the cockpit. Drainage and ventilation will be provided. Access to the pilot house top will be provided through a hatch accessed from within the cockpit area, above the seat.
The foredeck will remain clear, except for two sky-lights and the windlass / anchor arrangement. If a life raft is carried separately from the skiff, it will be stowed immediately forward of the wheel house, as drawn. Lifelines will be provided all around.
During the early design stages, two deck and inboard arrangements were explored using the same hull design. For a look at the alternative design, click here.
The interior of Gulliver is specified as follows:
Fuel stowage will be in four main tanks. Two diesel fuel tanks will be below the wheel house sole to port and starb'd, and two others will be below the sole forward of amidships. There will be a separate fill for each of the aft fuel tanks, and a common fill for the two forward fuel tanks.
A diesel day tank will be provided, and will hold 60 gallons. There will be a diesel fuel manifold arranged to allow fuel 'polishing' and to allow fuel transfers for trim. The day tank will be a "clean tank" only, and will not be able to be filled from on deck.
Smaller tanks for lube oil and waste oil will be provided. Consideration will be given to locating the lube and waste oil in the keel aft, as drawn. The lube oil and waste oil tanks will be connected to both engines, and hand pumps will be provided to make oil changes. Alternately, the aft portion of the keel may be used as a coolant tank, described later with the engine.
Water tanks will be located below the sole forward of amidships, as drawn. Water tanks will be filled from on deck, and from a rain catchment system, and from a watermaker.
Air for the engine space will be via "exit air duct fan." This allows maximum protection of the interior spaces from the engine room odors, noise, and heat. Engine and engine room ventilation specifics... (to be detailed).
HVAC: There will not be an Air Conditioning system. There will instead be a high capacity fan ventilation system for the living spaces. There will be forced air heat or hot water radiant heat throughout the vessel, including the pilot house.
Fuel capacity will be 900 gallons. Allowing 15% of that as a reserve (135 gallons) will provide an ample cushion, bringing the "available" fuel capacity to 765 gallons. The main engine will drive a 12 VDC high capacity generator. There will be little reason to use the auxiliary engine under way, therefore generator fuel usage has not been considered in the range calculations. With 765 available gallons, the approximate range of the vessel has been estimated as follows:
The main engine chosen for this work is a Lugger L439D by Alaska Diesel Electric. It is a naturally aspirated diesel, designed to operate up to 2,200 rpm continuous, and produce 67 hp at that rpm. It is assumed that the engine will be operated at less than 1800 rpm for most cruising. Continuous (M-1) rating at 1800 rpm is ±57 hp.
Expected power requirements using 765 gallons, published continuous duty engine power curves, a specific fuel consumption of .0625 Gal/hp/hr, and assuming 50% overall propulsive efficiency, are approximately as follows. These estimates consider additional losses (average sea state, minor fouling, etc.) These estimates do not consider added paravane drag:
| S/L Ratio | Knots | HP | RPM | GPH | NM Range |
| 1.35 | 8.5 | 66 | 2150 | 4.1 | 1580 |
| 1.27 | 8 | 50 | 1600 | 3.15 | 1950 |
| 1.2 | 7.5 | 36.5 | 1150 | 2.3 | 2500 |
| 1.15 | 7.25 | 30 | 1000 | 1.9 | 2900 |
| 1.125 | 7 | 27 | no data | 1.7 | 3200 |
| 1.05 | 6.5 | 20 | no data | 1.25 | 4000 |
| 0.95 | 6 | 14.4 | no data | 0.9 | 5000 |
The "design speed" for long range voyaging with this hull is assumed to be ±7.5 knots. It is preferred that the propeller revolutions be kept within the range of between 500 and 750 RPM. Maximum propeller size with the proposed keel configuration is 28" to 30" diameter.
A Hundested Controllable Pitch assembly will be used, combined with a Mekanord gear for pitch control. A 3.5 to 1 reduction will be used, and the Hundested propeller will have three blades. Control will be effected hydraulically by the Mekanord gear. There will be no reverse gear. Reverse will be available by reversing the pitch.
An integral keel cooling tank, if provided, will be sized for a maximum of 80 horsepower continuous, which will be expected to serve even in the tropics. Alternately an external keel cooler arrangement will be made.
Alternate engine choices will be made on the basis of being heavy duty, and low speed, within the range of power described above. An alternate engine which will fit the same beds (it uses the same block) is the John Deere 4039 DFM. The John Deere and the Lugger offer nearly identical performance and range, and are of nearly the same weight.
Vessel performance expected from the auxiliary is from 5.5 to 6.5 knots. This engine, at 2400 rpm, produces 11.5 hp, and will be expected to be able to drive the boat at 5.5 knots in average conditions. The auxiliary will be used for 12 VDC battery charging (and therefore refrigeration, etc.) whenever the vessel is not under way. If a dive compressor is provided, the auxiliary engine will drive the compressor via an electric clutch.
A thorough sound package will be provided over the auxiliary, as would be done for a generator. Good access will be preserved for all engine maintenance needs.
There will be three battery banks: one for starting the main engine, one for starting the auxiliary engine, and one for the house. The house bank will be the biggest, and will have the equivalent of at least three 8D's (possibly four). Each engine will have a 1-2-Both switch that will allow it to be started either by its own start battery or by the house battery. Both engines will have a dual output, high capacity alternator that will charge its own start battery and the house battery. All batteries will be of the relatively new AGM type.
A combination inverter/charger will be attached to the house bank for AC. A wind generator will also charge the house battery. The four charging sources feeding the one house bank will be manually chosen. If available, an automatic "smart controller" will be used.
A separate battery will be provided in the wheel house, and will run the electronics there. This battery will normally be in parallel with the house, but will be able to be isolated if necessary, preserving communications and navigation instrumentation independently of other demands.
Other instruments will be: Flo-scan fuel flow meters... (other instruments to be determined). There will be a searchlight, electronically controlled from within the pilot house, and capable of being moved to the main deck or the side of the wheel house, if needed, for canal clearance.
Communications: There will be a commercial duty VHF / loud hailer; a HF / SSB / Ham radio (probably 2 separate units); Inmarsat-C (probably Trimble Galaxy, providing a backup GPS capability); Furuno weather fax receiver. Antennas for HF may employ the forestay, with the possible use of whips for canal travel. The weather fax will have it's own antenna. The SSB / Ham rigs may share an antenna via a manual switch. Issues: RF noise generated by alternators, chargers and inverters must be eliminated.
Chart Stowage: Chart storage space will be provided in the pilot house seat. Charts will be stored flat in drawers on each side, and long term chart storage will be in a large bin in the center seat. The sextant will be stowed in the center bin, along with flares, a manual horn, a whistle, and a manual searchlight.
Refrigeration: There will be a 12 VDC refrigeration compressor, and a holding plate located in an ice box with generous insulation. Cooling will be via sea water heat exchanger.
Cooking: Propane range with oven. The stove of choice is a Broadwater.
110 VAC appliances: There will be a bread maker, used to knead and rise the dough only, unless shore power is available, when it will be used for baking as well. This will be run from the inverter off the house bank of batteries. Occasionally, 110v will be for power tools, a possible TV/VCR (this may be a 12v unit), and possibly for computers or for a printer. Several 12 volt jacks will be provided for various 12 VDC loads, such as a laptop computer. The boat will be wired for ethernet, both in the pilot house and below.
Entertainment: Two car stereos (one in the wheel house, one in the master suite). There will be a TV/VCR in the salon (location to be determined).
Water: A watermaker will be provided. It will be belted from the main engine. It will be automatically clutched, keeping the water tanks topped up whenever under way. A catchment will be provided to receive rain water from the foredeck. Water tankage will be split into two separate tanks. Hot water will be provided for showers, both in the head and on the aft deck. Consideration will be given to incorporating this into a diesel heater which can alternately function as a water heater.
Bilge pumps: several, of good size and capacity (to be detailed). At least one large capacity manual pump, and one large capacity pump on both the main engine and the auxiliary engine-belt driven, and clutch controlled.
The windlass will be capable of operating two rodes independently. Alternately, two windlasses will be provided. There will be two independent chain lockers forward. Windlasses will have remote controls so that anchor handling may be done from the wheel house. An additional windlass control will be located on deck.
There will be six heavy mooring bitts, as drawn. The two mooring bitts forward will be slightly larger. Hawse holes will be provided forward and aft at the sides, and aft on the centerline. Hawse holes will be stainless lined. The midship bitts will be high enough for lines to be taken over the top of the toe rail.
If it can be conveniently arranged, there will be hawse pipes forward for the anchors to be drawn into and housed. If this is not suitable, there will be a short "plank" forward to stow the anchors.
Lifelines will be placed around the forward deck, as indicated on the drawings. Consideration will be given to a bow pulpit for working with the anchors.
A "MOB" life ring, line and marker buoy will be stowed aft in the cockpit.
Anti-roll stabilizing will be provided by trailed paravane stabilizers. Location for these will be at Station #14 per preliminary drawings. This stabilizer system provides the best performance for slow speed and heavier conditions.
Per PRELIMINARY results, the range of positive stability is ±125 degrees with a light load of 33,000#. The range of positive stability is ±135 degrees with a full load of 43,600#. These are preliminary results, and will be finally determined only after the vessel is fully detailed, and the VCG is known.
The above stability figures do not consider the negative effect of free surface within the tanks. The above stability figures do not take credit for the added stability provided by the wheel house.
Alternately, considerable construction time may be saved by having the structural components defined by computer modeling, and then sent to a plasma cutter. Modeling the structure will add a small amount of computer labor, for a fairly large potential savings in construction labor. General estimates range from 30% to 50% savings in construction time, depending on hull form and the complexity of internal structure. For this hull, the primary benefit will be to computer cut the deck beams, the wheel house components, the stem, the floors, and all the plating.
Scantlings will be 100% according to ABS Rules. Scantlings will be derived either from criteria given in "ABS Rules for Motor Pleasure Yachts," or from "ABS Rules for Steel Vessels Under 200 Feet." Alternate scantling rules may be considered.
Stations will be spaced from 28" to 39" depending on the final requirements of the interior arrangement. Long's will be approximately spaced from 10" to 14" throughout, depending on the frame spacing chosen. Plating will be 3/16" on the topsides and the bottom; 1/4" on the keel sides; 3/4" on the keel bottom. All decking will be 10 gauge plate.
The Pilot House material will be 3/16" aluminum plate on 3.5" frames, with long's as needed. It will be mounted using a bi-metal strip welded to the deck. The "wing plate" aft of the pilothouse doors above the bulwark will be aluminum, with a boundary at the top of the bulwark.
Bulwark top, gunwale, house edges, etc. will all be of pipe, per construction drawings. Gunwale pipe will be Sch 80; all others will be Sch 40. House top perimeter will be aluminum pipe.
A preliminary ballast amount and location will be specified. The ballast final quantity and location will be determined after launch, with the vessel complete, and all tanks loaded halfway, ballast being shifted until neutral trim is achieved. Once located, all ballast will be permanently bedded in cement, and topped with a waterproofing, such as "Silver Seal" as is used on mobile home roofs. Silver Seal is easily cleaned, and is not dissolved by fuel or other solvents which may get spilled in the bilge.
To achieve best steering efficiency, an end-plate will be placed at the bottom of the Rudder. An end plate at the top of the rudder is unnecessary. In effect, the hull provides an adequate "end-plate" at the top of the rudder.
The axis of rotation will provide a counterbalance for easier steering. The options are generally as follows:
The shape of the Rudder will be a fat NACA 0012 type foil. This foil selection will produce the most lift with the least drag. A foil shape will provide optimum steering, and will have a large range of steering angle without stalling with considerably less drag than a flat plate rudder.
A flat plate rudder with a wedge at the trailing edge is an alternate. Though easy to build, it is not efficient. Steering is excellent, but drag is excessive.
Our preference will be to use a NACA 0012 foil shape with an end plate at the bottom only, and a 10% counterbalance. The rudder heel fitting will be removable, allowing the rudder to be dropped without requiring a flange at the top. The added drag of a top flange will be eliminated. The rudder heel bearing will be built as illustrated (to be detailed).
Interior: After hull fabrication the interior of the hull will be "brush blasted" to clean all welding and cutting areas, and primed with Devoe 302 or 201 primer. A minimum of two coats of high build will be applied to the primer, using either Devoe 230 or 235. Where insulation will be applied, the combination of barrier coatings and primer will have a minimum thickness of 12 Mils DFT. A minimum of two coats of Devoe 229 will then be applied to all areas which will remain uninsulated and without ceiling (bilge, mechanical areas, lazarette and forepeak).
Tanks: After thorough blasting to remove all traces of the original 302 primer, all tanks will be coated with a minimum of three coats of Devoe 235. Water tanks will use colors suited for potable water. Minimum coating thickness will be 16 mils DFT.
Exterior: After fabrication, all exterior areas will be re-blasted, as needed, to clean all surfaces thoroughly and to give adequate tooth to the paint, then primed as follows: The deck and house, down to the gunwale pipe, will be primed with Devoe 302. From the gunwale pipe to the keel bottom will be primed with Devoe 201. After priming, all exterior surfaces will receive a minimum of two coats of Devoe 230 or 235. Minimum thickness will be 16 mils DFT before bottom paint and color coats. From the waterline upward, all surfaces will be color coated with two coats of either Devoe 229 Acrylic Epoxy, or Devoe 379 Polyurethane. Below the waterline, will be a minimum of two coats of a high copper content anti-fouling.
All traces of the original 302 primer will be removed within all tanks and below the gunwale pipe. Aluminum surfaces of the pilot house will receive the same system as elsewhere.
Last updated 7 August 97 by Charles Vollum
