DESIGN AND INITIAL TEST OF ONR 
SUPERCAVITATING HYDROFOIL BOAT XCH-6 
Glen J. Wennagel 
Dynamic Developments, Inc. 
Babylon, New York 
INTRODUCTION 
The Grumman Aircraft Engineering Corp. and its affiliate, Dynamic Developments, Inc., 
are engaged in research and development programs directed toward practical, high-speed 
hydrofoil systems. Emphasis is placed on application to vehicles with water speeds 
between 50 and 100 knots. Three of the test programs which assist in this effort are con- 
sidered to be of special interest to the Third Symposium on Naval Hydrodynamics. The 
first of these programs utilizes a whirling tank facility which enables hydrodynamic and 
hydroelastic tests on waterborne or underwater devices up to speeds of 100 knots. The 
second program utilizes a pendulum facility wherein hydrodynamic models swing through a 
water tank of variable water temperature and, consequently, variable vapor pressure. 
The third test program utilizes a research and test craft with supercavitating surface- 
piercing hydrofoils, a supercavitating propeller and a gas turbine power plant. This vehicle 
has been chosen as the subject for discussion herein. Construction and initial tests have 
been performed under Contract Nonr 2695(00) with the Office Of Naval Research. The pur- 
pose of this test program is to determine the hydrodynamic efficiencies of the propeller and 
hydrofoil system over a speed range between 0 and 60 knots, and to investigate corrosion 
preventive measures for gas turbine engines operating in a marine environment. 
GENERAL CHARACTERISTICS 
General characteristics of the craft are shown in Figs. 1, 2a, 2b, and 2c. Overall 
length, with foils extended, is 23.3 feet. Clearance between the keel and the 60.0-knot 
water line is 2.08 feet. Takeoff gross weight, with one pilot, is 2550 pounds. Table 1 
gives a complete weight statement. 
HULL 
The hull has been constructed from an aluminum sport boat manufactured by Grumman 
Boats, Inc. Three primary modifications have been made to the basic hull. The first is the 
addition of Lockfoam covered with three layers of fiberglass cloth to the forebody bottom. 
The new forebody lines were established through the addition of ribs installed external to 
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