The travel of the piston between its extreme points: top dead center and bottom dead center.

Structural engineering is a sub-discipline of civil engineering in which structural engineers are trained to design the 'bones and muscles' that create the form and shape of man-made structures.

A close-up inspection of the hull structure and ultrasonic thickness measurements (gauging).

A hydrostatic test carried out to demonstrate the tightness of the tanks and the structural adequacy of the design.

A structural trap is a type of geological trap that forms as a result of changes in the structure of the subsurface, due to tectonic, diapiric, gravitational and compactional processes.

The internal structure of Earth, structure of the solid Earth, or simply structure of Earth refers to concentric spherical layers subdividing the Solid earth.

Outboard column-like support or V-arranged supports for the propeller shaft used on some ships with more than one propeller instead of bossings.

Student Energy is a global youth led organisation empowering the next generation of leaders to accelerate the transition to a sustainable, equitable energy future.

A stuffing box or gland package is an assembly which is used to house a gland seal. It is used to prevent leakage of fluid, such as water or steam, between sliding or turning parts of machine elements.

The oil drained from the piston rod stuffing boxes is mixed with sludge from the scavenge air space and has to be cleaned before it is led back into the lubricating system.

The sub-Arctic climate (also called subpolar climate, or boreal climate) is a climate characterised by long, usually very cold winters, and short, cool summers.

Sub-bituminous coal is a type of lower grade coal which contains 35%-45% carbon.

Subcritical steam – up to 705 °F (374 °C) and 3,208 psi (221.2 bar) (the critical point of water)

The division of a hull into a series of watertight compartments by means of transverse and longitudinal watertight bulkheads.

Initial draughts of the ship before damage which must be considered when calculating the attained subdivision index A.

The measure of the ability of a ship to survive flooding accidents caused by collision or grounding.

The greatest projected moulded length of that part of the ship at or below deck or decks limiting the vertical extent of flooding with the ship at the deepest subdivision loadline.

Sublimation is the transition of a substance directly from the solid to the gas state, without passing through the liquid state

A power transmission cable used carrying electricity, usually laid on the sea floor.

An arc welding process that uses an arc or arcs between a bare metal electrode or electrodes and the weld pool.