A ring main unit is a factory assembled, metal enclosed set of switchgear used at the load connection points of a ring-type distribution network.

Ripple control is a common form of load control, which involves superimposing a higher-frequency signal onto the standard 50–60 Hz of the main power signal. When receiver devices attached to non-essential residential or industrial loads receive this signal, they shut down the load until the signal is disabled or another frequency signal is received.

The distance above the keel that a tangent to the bottom at or near the keel cuts the line of maximum beam amidships.

A conducting pipe connecting sub-sea wellheads, templates or pipelines to the equipment located on a buoyant or fixed offshore structure, (ABS).

The international standard definition of risk for common understanding in different applications is “effect of uncertainty on objectives”. Risk is the probability that exposure to a hazard will lead to a negative consequence.

Risk analysis is a technique used to identify and assess factors that may jeopardize the success of a project or achieving a goal.

A risk assessment determines possible mishaps, their likelihood and consequences, and the tolerances for such events.

Risk management is the identification, evaluation, and prioritization of risks (defined in ISO 31000 as the effect of uncertainty on objectives) followed by coordinated and economical application of resources to minimize, monitor, and control the probability or impact of unfortunate events or to maximize the realization of opportunities.

A low-profile vessel designed for navigation in coastal waters and river/sea trading. As a consequence, a river/sea vessel features a shallow draught in loaded condition as well as low overhead clearance in ballast condition.

A vehicle on wheels fitted with a tank or tanks intended for transport of gases, liquids or solids by both road and sea modes of transport.

A commercial vehicle, semi-trailer, road train, articulated road train or a combination of vehicles, as defined in Assembly resolution A.581(14).

Deposition of rocks onto subsea pipelines to provide protection against anchors and fisherman nets when burying pipes is impractical.

Rock-fill dams are embankments of compacted free-draining granular earth with an impervious zone.

The act of checking the presence of the passengers and crewmembers, e.g. at assembly stations, by reading aloud a list of their names.

The difference between unstabilised and stabilised roll angles at resonance in regular sinusoidal beam seas with a specified maximum waveslope and at a specified ship roll damping ratio.

A variety of roll stabilisation systems are available to reduce ship motions and forces which can cause cargo damage, undermine passenger comfort and crew efficiency, and increase resistance.

A rolling blackout is an intentionally-engineered electrical power shutdown in which electricity delivery is stopped for non-overlapping periods of time over different parts of the distribution region.

Cargo on wheels, such as trucks, trailers or diverse rolling general freight and which can be driven or towed onto a ship.

The modern cargo handling technique first introduced in 1950s. Cargo is literally rolled on board ro-ro ships.

The main feature of the three ro-lo vessels delivered by Gdynia Shipyard is multi-access system designed by MacGREGOR.