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The Beetle is a type of vessel called a "jetfoil."
Different from ordinary ships and vessels in terms of speed and propulsion mechanism, a jetfoil provides a comfortable voyage even when waves are violent. A jetfoil can also achieve a high-level of safety.
<<Size and Structure of the Beetle>>
| Overall length with hydrofoils up |
30.3m |
| Overall length with hydrofoils down |
27.4m |
| Length between perpendiculars |
24.0m |
| Molded breadth |
8.5m |
Maximum breadth
(Including flared section of main deck) |
9.1m |
| Molded depth (From baseline to main deck) |
2.6m |
| Draft (molded load draught) |
1.5m |
| Extreme draught with hydrofoils up |
2.2m |
| Extreme draught with hydrofoils down |
5.0m |
| Total tonnage |
164 ton |
| Capacity |
200 passengers |
| Foil-borne speed |
Approx. 45knot (approx. 83km/h) |
| Main engines |
3,800-ps gas turbines (2 sets) |
| Propulsion system |
Water jet propulsion machines
(2 sets) |
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First, a jetfoil advances itself by the thrust of its water-jet propulsion system that is driven by gas turbine engines (propulsive force). Then the vessel floats above the sea surface due to the lifting power of the frontal and rear hydrofoils (taking off) and goes into a cruising mode (foil borne).
The foil-borne movement of a jetfoil is very similar to that of an aircraft. That is, when striking a balance with the hull, a jetfoil regulates the flaps on the trailing edge of the hydrofoils with an automatic level-stabilizer so that the hull remains at a certain altitude from the water surface at all times. When making a circular movement, the vessel gives a tilt to the hull toward its internal side and rotates smoothly. In short, a jetfoil is a "flying machine on the sea" that gets its lifting power not from air but from seawater. Because the density of water is about 800 times that of air, a jetfoil is able to fly above the sea with smaller wings than those of an airplane and at a lower speed. |
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In the Beetle, the automatic level-stabilizer moves the flaps on the frontal and rear hydrofoils in order to keep the hull level all the time. As a result, the Beetle can usually cruise over waves as high as 3.5 meters. When a wind forces the hull to tilt even slightly, sensors will recognize it and even up the vessel. In an emergency, the Beetle can make an emergency stop within a short distance comparable to that of an automobile by landing on the water and employing counter-rotation of water jet engines. The vessel can avoid a floating object easily. In case it hits a large floating object, however, shock absorbers installed on the frontal and rear hydrofoils guarantee passengers' safety. |
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