Measured in decibels it is used to establish the noise level in an area or in the disgn of an area that will contain high noise. The measured results are primarily used to ensure that working areas comply with legislation on noise levels and to advise workers on the type of noise suppression protective equipment is required.

A pipe which leads down to almost the bottom of a tank to enable the depth of liquid to be measured by a sounding tape. A striking pad must be located on the tank bottom beneath the pipe.

Sour gas is natural gas or any other gas containing significant amounts of hydrogen sulfide (H2S).

Emergency source of electrical power – A source of electrical power intended to supply the emergency switchboard in the event of failure of the supply from the main source of electrical power, (acc. to SOLAS Chapter II-1, Part A).

In petroleum geology, source rock is rock which has generated hydrocarbons or which could generate hydrocarbons.

If the vessel operates in areas where SOx emissions are controlled, compliance can be achieved using low sulphur fuel, or by cleaning exhaust gases using SOx scrubbers.

A space heater is a device used to heat a single, small area. Space heaters are powered by electricity or a burnable fuel, such as natural gas, propane, fuel oil, or wood pellets.

Space-based solar power (SBSP) is the concept of collecting solar power in outer space and distributing it to Earth.

Separate compartments including holds and tanks.

Spallation is the process in which a heavy nucleus emits numerous nucleons as a result of being hit by a high-energy particle, thus greatly reducing its atomic weight.

A spar is a marine structure, used for floating oil/gas platforms.

see OFFSHORE PRODUCTION AND STORAGE INSTALLATIONS.

A device which prevents spark from the combustion in prime movers, boilers, etc. from reaching the open air.

A spark plug is a device for delivering electric current from an ignition system to the combustion chamber of a spark-ignition engine to ignite the compressed fuel/air mixture by an electric spark, while containing combustion pressure within the engine.

An internal combustion engine where a fuel/air mixture is drawn into a cylinder and ignited by a spark during compression.

Metal particles expelled during fusion welding that do not form a part of the weld.

Enclosed spaces above or below the bulkhead deck intended for the carriage of motor vehicles with fuel in their tanks for their own propulsion...

Hull penetrations for installations such as echo sounder, speed log, and impressed current cathodic protection system.

A mechanically self-propelled ship which, by its function, carries on board more than 12 special personnel, including passengers.

Specific energy or massic energy is energy per unit mass.