Aleutian 70, Global Surveyor

World tested cruising comfort, hurricane tested steel strength.

MAJOR DESIGN DECISIONS

Length over deck. 19.95m
Safety, Comfort, and speed, generally increase with size. 20m was chosen as the largest that could be easily handled by a crew of two while providing enough room t o sleep a possible 14 and provides exceptional comfort with lesser numbers.

The deck length was kept just below 20m to minimise possible regulatory impacts.

Length Water Line. 17.71m.
Maximised to increase internal space, reduce the entry and exit angle of the hull and to give the greatest sailing speed.

Beam Over all. 5.00m
A moderate beam is utilised to reduce resistance especially to windward and minimise the broaching tendencies of wider hulls. ( Coincidentally 5m is also the maximum that is generally road transportable in the UK ) The waterline beam is maximised to give good initial stability and load carrying without increasing deck weight. This also gives a massive amount of usable room down to sole level in the accommodation.

Draft. 2.85m
Is sufficient to give a good sailing performance without being unduly deep. The wide keel gives high structural strength and allows the ballast, water and fuel to be carried low. The sump of the engine also fits into the keel. This in turn means a low and continuous sole level throughout the accommodation. The overall effect is to lower the centre of gravity thereby increasing the vessel's stability both initial and ultimate.

Freeboard.1.75m Fwd 1.45m Aft
A fully flush deck was chosen for its inherent strength, simplicity and the gift of maximum useable deck space.

Deck

The windage of the hull and height of the centre of gravity of the deck, mast and rigging, together with the heeling moment of the sails all increase with an increase of freeboard. The low height of the cabin sole allows a moderate to low freeboard to be maintained while still keeping a general 2m (6'06') of headroom in the accommodation.

A straight sheer amidships increases the longitudinal strength of the hull and maintains headroom throughout the accommodation. The camber of the deck and bulwark height give sheer to the profile.

Hull Construction
Radiused chine construction was chosen to give the sea keeping characteristics of round bilge while being economical to build. The Design Water Line is set at a displacement of 52 tonnes thereby including near maximum stores, crew and water, together with a large quantity of personal equipment. Many other vessels are designed to an unrealistic light displacement and spend most of their time overloaded, with a consequent loss of, safety and performance.

Rudder
The rudder is larger than normal to give better balance under sail and the directional stability of a long keel. A spade rudder was chosen so as to reduce steering loads by being fully balanced and to give a smaller turning circle ahead, and better control at low speeds and when going astern. The rudder is hung on a high strength 12 mm thick steel stock 193.7 mm diameter which provides greater strength than most skegs.

Wheelhouse / protected cockpit
It is not pleasant to char boil under a tropical sun or be deluged by freezing spray in the North Sea. A wheelhouse is therefore vital both for morale and safety. The dimensions required to give headroom and visibility are fixed by the human form, the wheelhouse could easily have turned into a box. It is suggested that this vessel has an exceptionally nice looking wheelhouse.

Depending on personal preference all the Navigation and engine instruments, radar etc are within the Wheelhouse, close at hand for the helmsman.

An inside wheel is not thought necessary as a dodge control could easily be fitted to the autopilot. The position of the wheel at the front end of the open cockpit allows the helmsman maximum uninterrupted vision, keeps him clear of the winch men and gives him maximum shelter.

The relatively high binnacle and moderate diameter wheel means that crew can easily slide alongside the wheel while the helmsman has the choice of steering from inside the shelter, standing behind the wheel, or sitting alongside. When berthing a step raises the helmsman's eye level for even better visibility.

Anchor
140kg genuine CQR. Self-launching and recovery (never needs touching). on 80m of 16mm chain. Not only did this as-new, but surplus anchor cost less than 1/10th of one half the size, but restful nights are assured.

Bowsprit
Is strong enough to stand vessel vertically on end. Angled lower part to prevent pounding. Increases sail area with a shorter mast. Increases directional stability. Good place to set the cruising chute. Excellent place for the anchor and keeps the chain clear of topsides in wind over tide situation. The enclosed leads are strong enough to shackle moorings eliminating chafe. Best place to watch the dolphins and put the world to rights.

Forepeak
A fully watertight collision bulkhead to the accommodation is the second line of defence against semi-submerged containers. (the first is 7mm steel plating) Place to stow all the ropes, sails fenders, inflatables and anything else that might be damp, separate from the accommodation. Position for echo-sounder transducer, giving 5m warning of shallow water.

Capstan
Set well aft to lead the 450kgs of Chain into the forepart of the keel where it is nearer the centre of the vessel for better motion, and low down for stability. As well as controlling the anchor it can be used for adjusting moorings (has pulled the vessel across 200' of mud), and hoisting sails.

Deck
The large uncluttered area gives a huge space for relaxing and working the vessel. The deck can also be used to collect drinking water at the rate of 600 litres for every 10mm of rain.

Accommodation
Fixed berths for 14 persons. All berths are very large and secure with 6' foam mattresses. The saloon is 5.6m long giving room for 20+ to enjoy cocktails. All the major weights are contained low down within this central section; namely 14 tonnes lead, 4 tonne of fuel and water, and 1 tonne of engine. There are 5 transverse and one longitudinal watertight bulkhead. There is only one seawater inlet, which feeds the engine and loos. The first valve is 150mm above the waterline on a 10mm wall thickness steel standpipe. The water filter is instantly visible and can be quickly cleared if blocked. Domestic discharges all go into a 300litre-holding tank, which can be pumped overboard through an above water fitting. The large centre steel hatch not only allows direct removal of the main engine but can also be left open in following winds of less than force 6 to give a massive amount of light and ventilation into the accommodation.

Rig
A cutter rig efficiently divides the total area into manageable sizes with good flexibility. It allows the mast to be nearer to the maximum beam of the vessel giving the best staying angle, which increases the security of the whole rig by reducing the loads.

Deckhouse
Keeps the crew out of the rain, spray and freezing wind in high latitudes and out of the direct impact of a vertical sun in the tropics. Not only is this hugely comfortable, it also massively reduces the risks of hypothermia or sunstroke. It also reduces fatigue and worry, which can adversely affect decision-making. Long term it can help prevent skin cancer.

Large spade Rudder
Increases directional stability. Will steer the vessel down to 1/20th knot when going ahead. It also gives very positive steering when going astern. Connected to give 50? of helm allows the vessel to turn with a radius of 10m. Its rudderstock of nearly 200mm diameter means it is not going to fall off.

Self-Steering
This gear steers the vessel effectively in conditions between 5 and 70 knots of apparent wind. allowing single-handed ocean watch keeping.

Keel
The medium length fin keel is of wide cross section to give massive strength. It also allows the lead to be carried as low as possible with capacity above for 1200 litres of fuel. The width also allows room for the lower part of the engine, which can then be fitted beneath the saloon floor massively increasing the useable space in the accommodation.

The bottom plate is 25mm thick, which gives piece of mind when navigating by Braille. It also allowed the easy welding of a wing keel, which reduces synchronous rolling by about 40%.
Global Surveyor