Hull DesignWave-piercing

A wave-piercing boat hull has a very fine bow, with reduced buoyancy in the forward portions.

When a wave is encountered, the lack of buoyancy means the hull pierces through the water rather than riding over the top - resulting in a smoother ride than traditional designs, and in diminished stress on the vessel and crew. It also reduces a boat's wave making resistance.

Zumwalt class destroyer (DDG-1000)

The Zumwalt class destroyer (DDG-1000) is a planned class of United States Navy destroyers, designed as multi-mission ships with a focus on land attack.

The Zumwalt-class destroyers are multi-role and designed for surface warfare, anti-aircraft, and naval fire support.

The vessel's appearance has been compared to that of the historic ironclad.

It will have a wave-piercing tumblehome hull form whose sides slope inward above the waterline. This will reduce the radar cross-section, returning much less energy than a more hard-angled hull form.

USS Independence (LCS-2) It is intended as a small assault transport that can take on

various capabilities with the installation of mission modules. The ship is a trimaran design that can make more than 40 knots (74 km/h; 46 mph), and was delivered to the Navy at the end of 2009.

M-hullIn the last few years the ship building industry

has seen a variety of new technologies entering the market. If observed carefully, it can be seen that all the advanced technologies are more inclined towards environmentally friendly traits and improved efficiency.

M-hull technology is an innovative development that uses a specifically M shaped hull to create an air cushion below the vessel in order to reduce the air drag.

The M shaped hull captures the bow wave energy to form an air cushion, which thus reduces the drag. The reduction in drag provides exceptional speed to the vessel, a trait that conventional vessels are devoid of.

Understanding What Happens Beneath the Vessel

A conventional vessel when moves through the water, it generates a bow wave which is followed by a trough and stem wave. The formation of bow wave depends on the speed of the vessel, its draft, water depth and shape of the bow.

The bow waves have a peculiar trait. They move forward at a faster speed initially and then gradually lose speed. The waves move at an angle to the hull and generate an energy that can be harmful to the nearby boats or structures. The M hull technology utilizes this energy for a better use by increasing the efficiency of the vessel and preventing wastage of the bow wave energy.

The design of M hull consists of three main features as follows:

the central displacement sectionthe planing tunnelsrigid skirts

The central displacement section is what supports the vertical skirts that are attached through out the structure. The design is made in such a way that the skirts are able to capture the hull waves inside the planing tunnel. The incoming bow waves spirals along the planing tunnels and trap the incoming air, forcing it towards the aft.

The planing tunnels also have a slope moving downwards to compress the aerated water for forming the air cushion and reducing the drag. This air cushion increases with the speed of the boat, thus providing additional thrust to the vessel and also reducing the fuel intake.

StilettoThe first vessel to be made by using M Hull

technology is Stiletto, a craft entirely made of carbon fiber. Stiletto is capable of speed up to 50 knots. As the vessel moves forward the stern wake energy that is flowing aft is captured by millions of bubbles under the ship. This characteristic not only helps in making an air cushion underneath the ship but also to absorb the noise made by ship’s machinery. The technology is presently being used by U.S Navy; however it will soon be seen in large transport and commercial vessels.

Combines ship design elements for a new relationship between hull, air and water

•Wave piercing front end•Multiple lifting surfaces•Captured wave/air lift•Automatic ride control•Reduce viscous drag•Dynamic stability

•Reducted pitch and roll•Very shallow draft•Increased payload fraction•Shock Mitigation•Wake signature reduction

Advanced M-Hull Technology

In sea trials of a boat the boat operated downwind more efficiently at lower boat speeds, but upwind into a 10-knot breeze the boat was propelled at almost 25% greater speed than when operating downwind. Such unexpected characteristics of an M-shaped boat hull promise significant benefits, and so a need exists for ways to develop and exploit those characteristics.