Glossary: engineering

45 terms in this category.

• 15 ppm Bilge Alarm
  An automatic alarm fitted to an oily water separator that stops overboard discharge when oil content exceeds 15 parts per million.
• Auxiliary Engine
  A diesel generator engine providing electrical power for shipboard systems independent of the main engine.
• Azimuth Thruster
  A propulsion unit that can rotate 360 degrees, providing both thrust and steering without a conventional rudder.
• Bilge
  The lowest interior space of a vessel where leakage, condensation, and drainage water collects; must be pumped out regularly.
• Bow Thruster
  A transverse propulsion unit fitted in a tunnel through the bow section to improve low-speed manoeuvrability in port.
• Bridge Alarm
  An alarm system on UMS vessels that channels all critical engine room and safety alarms to the navigating bridge when the engine room is unmanned.
• Bunker
  Fuel oil carried aboard and consumed by a ship's main and auxiliary engines; also refers to the act of taking on fuel.
• Cargo Pump
  A large-capacity pump on a tanker used to discharge liquid cargo from cargo tanks to shore or to another vessel.
• Controllable Pitch Propeller
  A propeller whose blade pitch can be varied in service, allowing speed and thrust control without changing engine rotation direction.
• Crankcase
  The lower enclosed section of an engine housing the crankshaft, connecting rods, and bearing lubrication system.
• Crude Oil Washing
  A tank cleaning method using crude oil cargo as the washing medium to dissolve and remove waxy residue from tank surfaces.
• Dynamic Positioning
  A computer-controlled system that automatically maintains a vessel's position and heading using thrusters, without anchoring.
• Emergency Fire Pump
  A self-contained fire pump located outside the machinery space, capable of supplying fire mains if the main pumps are disabled.
• Emergency Generator
  A self-contained standby generator automatically supplying essential electrical power to safety systems if the main supply fails.
• Exhaust Gas Cleaning System
  A device fitted in the exhaust line that removes sulfur oxides from engine gases, allowing use of high-sulfur HFO under IMO 2020.
• Fixed Pitch Propeller
  A propeller with blades cast at a fixed angle to the hub; speed and direction are changed by varying engine rpm and rotation.
• Four-Stroke Engine
  An internal combustion engine requiring four piston strokes per cycle, widely used as medium-speed auxiliary and propulsion engines.
• Fresh Water Generator
  A distillation unit using main engine jacket water waste heat to evaporate and condense seawater into fresh water at sea.
• Generator Set
  A diesel-electric power unit installed in a ship's hold or on deck to supply electrical power to reefer containers.
• Heavy Fuel Oil
  Residual fuel oil with high viscosity and sulfur content, historically the primary bunker fuel for ocean-going vessels.
• Inert Gas System
  A system supplying inert gas (flue gas or nitrogen) to tanker cargo tanks to maintain an oxygen-deficient atmosphere and prevent explosion.
• Intermediate Fuel Oil
  A blend of heavy residual and distillate fuel oil with viscosity typically 180 or 380 cSt, used as main engine bunker.
• Jacking Gear
  A reduction-gear device coupled to the engine flywheel used to slowly turn the engine by hand or motor for inspection.
• Main Engine
  The primary propulsion engine driving the ship's propeller shaft, typically a large slow-speed two-stroke diesel on cargo ships.
• Marine Diesel Oil
  A distillate fuel oil with low sulfur content, used in auxiliary engines and during port operations where ECA rules apply.
• Mast Riser
  A large-diameter high-velocity vent pipe fitted to a tanker's mast to discharge cargo vapours safely above ignition sources.
• Oil Discharge Monitoring and Control System
  Equipment on oil tankers that continuously monitors the oil content and flow rate of overboard discharges to ensure MARPOL compliance.
• Oil Mist Detector
  A crankcase monitoring device that samples air from each crankcase compartment and alarms if oil mist concentration reaches explosive levels.
• Oily Water Separator
  Equipment that separates oil from bilge water to reduce oil content to 15 ppm before overboard discharge under MARPOL.
• Pressure/Vacuum Valve
  A safety valve on a cargo tank vent that opens at set over- or under-pressure limits to protect the tank structure.
• Purifier
  A centrifugal separator that removes water and solid contaminants from fuel or lubricating oil before engine use.
• Reefer Container
  A refrigerated ISO container with an integral refrigeration unit maintaining controlled temperatures for perishable cargo.
• Scavenge Air
  Pressurised air supplied to the cylinder of a two-stroke diesel engine to expel exhaust gases and supply fresh charge for combustion.
• Sewage Treatment Plant
  A biological or chemical system treating shipboard sewage to standards permitting overboard discharge under MARPOL Annex IV.
• Shaft Alley
  The enclosed tunnel running through the stern of the ship enclosing the propeller shaft from the engine room to the stern tube.
• Slop Tank
  A dedicated tank on tankers used to collect cargo residues and tank washing water, allowing oil-water separation before discharge.
• Starting Air Receiver
  A pressure vessel storing compressed air at 30 bar used to crank and start the main engine and diesel generators.
• Stern Tube
  The watertight bearing assembly through which the propeller shaft passes through the hull from the engine room to the propeller.
• Tank Cleaning
  The process of removing cargo residues and gas from cargo tanks using water, chemicals, or crude oil washing prior to loading a new cargo.
• Turbocharger
  A device driven by exhaust gas that compresses intake air to increase diesel engine power output and fuel efficiency.
• Turbocharger Surge
  An abnormal flow reversal in a turbocharger compressor, evidenced by a loud banging or barking noise, caused by sudden load changes.
• Turning Gear
  An electric motor-driven gear unit that slowly rotates the main engine crankshaft for maintenance, cooling-down, or warming-through.
• Two-Stroke Engine
  A type of internal combustion engine completing the power cycle in a single up-and-down piston stroke, common in large slow-speed marine main engines.
• Unattended Machinery Space
  A classification notation permitting the engine room to operate without a watchkeeper at night, subject to enhanced alarms and automation.
• Very Low Sulfur Fuel Oil
  Fuel oil with a sulfur content of 0.50% m/m or less, required globally under IMO 2020 sulfur cap regulations.