The Navy’s first hydrofoil patrol craft was launched on this day 50 years ago, in 1962. Published in the September, 1963 issue of Proceedings, the following article describes the mechanics of the USS High Point, and the reactions from the people who witnessed the launch of the revolutionary craft.
USS High Point (PCH-1)
By Charles H. Nelson, Jr. Chief Journalist, U.S. Navy
She took off quickly, flew quietly, and landed smoothly. Thus the first public “flight” of the Navy’s revolutionary hydrofoil patrol craft High Point was described just a few short weeks ago. The High Point is a unique blend of aerodynamics and hydrodynamics, carrying within her 115-foot length-overall hull the newest hopes of the Navy’s antisubmarine warfare program.
Rear Admiral Ralph K. James, U. S. Navy, (ex-Chief, Bureau of Ships) in testimony before a special investigative subcommittee of the science and astronautics committee of the House of Representatives, explained in these words the mission of the High Point: “This ship shows tremendous promise for antisubmarine warfare where we need speed as never before. The modern submarine is capable of operating at tremendous pace when submerged. To close within kill range before it outruns sonar range is an increasingly tough task. Ideally, two hydrofoil patrol craft will operate together in a “grasshopper” or “leapfrog” technique. One will move slowly through the water in the displacement position listening for submarines … the other will fly ahead, then settle into the water and listen while its partner flies in turn. When the listener gets a submarine on its sonar, it will signal its partner to guide it to the target to track it down and drop a homing torpedo for the kill.”
This is the “grasshopper” technique as it is presently envisioned to be used by the High Point when she joins the Fleet. Frequent tests on the waters of Puget Sound have proven the ship’s capability to rise quickly to her foils, to fly silently, and to lower smoothly to her hull or cruising position.
The actual flight of the High Point creates an almost eerie feeling in observers. Although the vessel has a displacement of 110 tons, she rises almost effortlessly out of the water into the “flying” position. Her flight at speeds over 40 knots is so silent that the true speed is deceptive. She seems to glide through the water, the only sounds being the dripping of the water from her hull and the faint whine of her turbines.
The High Point is a ship, but the similarity between her and an aircraft is startling. She is constructed almost entirely of aluminum; she has a high-power propulsion system, a swept-clean look to her superstructure, and, of course, her underwater “wings.” Even her electronic control system is referred to as the “automatic pilot.” Located in the pilothouse are aircraft-type bucket seats mounted on sliding rails, aircraft-type throttle controls, a “yoke-type” steering column and an aircraft-type instrument panel.
The High Point is powered by two, 3,100 horsepower, gas turbine engines, each of which drives one set of propellers on the foils. A “nacelle” on each side of the aft foil holds two propellers, one on the aft and one on the forward end of the nacelle-a total of four.
When she is cruising on her hull, she receives her propulsion from a 600-horsepower diesel engine and a retractable inboard-outboard propeller arrangement. The ship’s foils are retractable. When they are retracted, her draft is five and one half feet. Her average draft when she is “flying” is only six and one half feet, and when she is resting on her hull, with the foils fully extended, her draft is approximately 16 feet.
The High Point has installed within her hull an electronic sensing device which will allow her to overcome one of the major problems which all hydrofoils face in rough weather-that of maintaining her “equilibrium.” Her submerged foil system is controlled through the transmission of electrical impulses from the ship’s bow to the control system’s electronic brain, which automatically adjusts quickly enough to keep the ship running above a rough sea. The “ailerons” on the foils are operated quite similarly to ailerons on the wings of an aircraft.
The most important remaining major problem facing the Navy and its contractors in the hydrofoil field is “cavitation.” At the present time, when the submerged foil cuts through the water, it provides the boat with lift because pressure on the lower surface is greater than on the upper surface. But as pressure lessens on the upper surface, bubbles form. At high speeds, the bubbles or cavities tend to form on the low pressure side of the foil. This phenomenon sets an upper limit of speed for hydrofoils. Very high speed foil systems are being studied with the Navy’s experimental hydrofoil Fresh-1, a 15-ton, twin-hulled catamaran powered by a jet engine. Fresh-1 is expected to reach 115 m p h. when mounted on super-cavitating foils.
The High Point is such a radical departure from conventional-type ships that her full potential is still an intangible. Some Navy officials foresee eventual uses for hydrofoils in the fields of amphibious warfare, transportation of UDT teams, commando units, and, perhaps, as high speed transports. At present, the future for the ship and her 13-man crew seems aimed at “rising quickly, flying smoothly, and delivering strikes at potential enemy submarines.”