air quality management information system |
for urban and industrial applications
Mobile sources of emissions: shipping
Marine diesel engines are the predominant form of power unit within the marine
industry for both propulsion and auxiliary power generation. In 2010 an
analysis of about 100 000 vessels indicated marine diesels powered around 99 %
of the world's fleet, with steam turbines powering less than 1 %. The only
other type of engine highlighted was gas turbines, used virtually only on
passenger vessels, and only used in around 0.1 % of vessels (Trozzi, 2010).
Diesel engines can be categorized into slow (around 18% of engines), medium
(around 55%), or fast (around 27%), depending on their rated speed.
The most common marine engine types include:
- Slow speed diesel engines with a maximum operating speed of up to 300 rev/min, although most operate at speeds
between 80-140 rev/min, two-stroke cycle, cross head engines of 4-12 cylinders.
Some current designs are capable of developing in excess of 4,000 kW/cylinder.
Such engines comprise the greater proportion of installed power, and hence
fuel consumption, within the industry.
- Medium speed diesel engines with a maximum operating speed in the range 300- 900 rev/min,
four-stroke cycle, trunk piston engines of up to 12 cylinders in line, or 20 cylinders in V formation.
Current designs develop power output in the range 100-2,000 kW/cylinder.
Engines of this type may be used for both main propulsion and auxiliary
purposes in the marine industry. For propulsion purposes such engines may be
used in multi-engine installations and will normally be coupled to the
propeller via a gearbox. Engines of this type will also be used in
- High speed diesel engines with a maximum operating speed greater than 900 rev/min
They are essentially smaller versions of the medium speed diesel engines
or larger versions of road truck vehicle engines; they are used on smaller vessels
and are often the source of auxiliary power on board vessels.
- Turbines: Steam turbines are largely being replaced by the more efficient
diesel engines which are cheaper to run.
Gas turbines are more widely used in warships, they are currently installed in
only a very small proportion of the merchant fleet, often in conjunction with
Relevant EC Directives include:
- EC Directive 98/70/EC (on the quality of diesel fuels)
- EC Directive 1999/32/EC (reduction of sulphur content in liquid fuels)
- EC Directive 2003/44/EC (diesel, 2-stroke gasoline and 4-stroke gasoline engines)
- EC Directive 2005/33/EC (amending 1999/32/EC)
| print page