Hamilton Water Jet Propulsion
The secret of efficiency is to choose the correct type of pumping unit with the correct flow and velocity relationship to suit the size and speed of the craft to be propelled. This unit is driven by a marinised conventional engine of suitable horsepower for the desired performance.
The Hamilton system is the result of lengthy experiments and many years of development. It has high efficiency, excellent manoeuverability and a host of impressive advantages over the conventional propeller; It has a very shallow draft with nothing extending below the bottom — no skeg, rudder, shaft, propeller. Obviously this is very desirable when running in shallow water or near underwater obstructions that could ruin a prop or wipe-off a rudder in short order.
Simplicity of installation is another important factor. The jet drive eliminates the need of gearboxes, reversing clutches and V-drives, since the pump itself, mounted above the bottom line, drives directly from the engine. For reversing, there is no need for a gearbox because the impeller continues to rotate always the same direction.
To slow, stop or reverse the boat, a mechanical deflector is manually activated over the jet stream diverting it in the opposite direction. This causes a reverse thrust and consequent opposite action to the boat's direction and motion. Steering is obtained by a pair of deflector plates arranged one either side of the nozzle. They are suitably connected by linkage and cables to the steering wheel. A powerful steering action results from turning the complete jet stream left or right.
Safety is also an important consideration. There is certainly nothing pleasant about getting run over by a powerboat—no matter what kind of drive it has! The prospect of getting chewed-up by a spinning razor sharp propeller is eliminated by the use of jet drive.
Today's high cost of fuel makes jet a really economical proposition. In similar hulls of comparable performance, jets out-perform outboards in fuel economy. Stated simply: you go further on a gallon of fuel when you are using a jet boat.
Maintenance is low with jet propulsion; the jet unit is powered by a standard reliable marinized car engine — the smooth, even load ensuring long life and economy. The impellers within the unit act as governors so that the engine cannot be overstressed. In fact, the life of jet units and engines can often exceed that of hulls! Jet units are made from corrosion resistant silicon-aluminium alloy, stainless steel and bronze and are specially protected against electrolytic corrosion.
Hamilton jet boats fall into two categories—River boats and Sea boats. River boats are generally a little different from sea boats in that they have shallow V hulls specially designed to plane in shallow river conditions. The jet unit itself exactly the same as fitted in the salt water deep V-models. The only limitations stem from hull design characteristics, not from the jet drive.
All Hamilton jet boats specifically designed for seagoing have Deep-V hulls for soft, comfortable cruising. They can, however, travel in shallower water than any propeller craft. . . a feature that you will find useful in flat tidal areas. No more fishing nets wound up in propellers either, you can cruise over them with impunity in a jet boat.
The engine is mounted low the water line in deep V hulls and this gives a much lower centre of gravity, ensuring greater stability than any outboard configuration under nay conditions.
Deep V jets drive through the sea, rough or smooth and recently have been cited by Surf Lifesaving groups as ideal for the wide range of requirements sea and surf rescues demand.
