Encyclopedia banner

Encyclopedia of Marine Technology


94 results


The electric connection of equipment to the main body of the earth to ensure that it is at earth potential. On board the ship, the connection...

EC directive on marine equipment (European Union Marine Equipment Directive)

The directive of European Commission about marine equipment for which international conventions require the approval of the national administrations as well as mandatory carriage on board.


see electronic chart display and information system.

Edge griding

The treatment of the edge before secondary surface preparation.

Edge preparation

The shaping of a plate edge for welding. This may take the form of a V, X, Y, or K edge profile.

Edible oil tanker

A tanker designed for the carriage of edible oils for food industry. The STAR BONAIRE is a sea/river tanker suitable for the carriage of all kind of edible oils.

Edible oils

Cocoa butter, coconut oil, palm oil, peanut oil, rape oil, soya bean oil, sunflower oil. Most of edible oils have a specific gravity of 0.89t/m3.

Effective clearing of the ship

The ability of the free-fall lifeboat to move away from the ship after free-fall launching without using its engine.


The ratio of output to input for a system or operation. It is usually expressed as a percentage.

Efficiency Rudder

A patented semi-balanced rudder developed by Wärtsilä Corporation. The Efficiency Rudder is characterised by a streamlined “torpedo”-shaped bulb on the rudder hornimmediately abaft and coaxial with the propeller hub.

EIAPP statement of compliance

When testing the engine for NOx emissions, the reference fuel is Marine Diesel Oil (Distillate) and the test is performed according to ISO 8178 cycles.


A pump that has no moving parts or a mechanical driver. The pumping action is created as a pressurized fluid, referred to as the motive or operating fluid supplied from an external source, passes through the ejector.

Ekranoplans, also wing-in-ground (WIG) effect crafts

Flying ships pioneered for military purposes in the 1930s by Russian aeronautical engineers. WIG craft flies just above sea level.

Elastic limit, yield point

The maximum stress that can be applied to a metal without plastic deformation.


The structural member capability of sustaining stress without permanent deformation, i.e. to recover its original size and shape after the stress has been removed.

Electric motors

The electric motor converts electrical energy to mechanical energy. The most frequently used type of electric motor is the motor powered by an alternating current supply: the AC-motor.

Electric network

All equipment and installations connected at the same rated voltage. - Isolated electric network – A system in which a conductor or the neutral is not connected to the ship hull in normal operation.

Electric network with earthed neutral

A system in which the neutral is connected to the ship hull in normal operation.

Electric podded propulsor

Azymuthing electric propulsion unit with the motor located inside the underwater housing (pod) attached to the hull.

Electric propulsion systems, electric drive systems

The concept of electric propulsion is over 100 years old with battery-powered vessels recorded in Russia and Germany around 1870. In 1893, one of the first electric boats ELECTRICITY carried passengers on the River Thames in England.

1 2 3 4 5
Download the Encyclopedia