singlescrew

Singlescrew is a term used in engineering to describe systems or devices that employ a single screw element for propulsion, material conveyance, or actuation. It is most common in discussions of propulsion and plastics processing, where the emphasis is on a single moving screw rather than multiple screws.

In maritime contexts, a singlescrew vessel is a ship propelled by a single propeller connected to one or more engines. This contrasts with twin-screw or multi-screw ships that use two or more propellers. Advantages of a singlescrew arrangement include simpler machinery, lower weight, and lower maintenance costs. Disadvantages can include reduced maneuverability, limited redundancy in propulsion, and performance that is highly dependent on hull form, propeller design, and engine matching. For larger vessels, twin-screw configurations are often preferred to improve handling and provide redundancy.

In plastics and food processing, a single-screw extruder uses one rotating screw inside a heated barrel to convey, melt, and pressurize material through a die to form a continuous product. Single-screw extruders are generally cheaper, more compact, and easier to operate than twin-screw systems, but offer less thorough mixing and dispersion, making them less suitable for highly viscous or highly filled materials.

Other uses of the term include single-screw actuators and various applications that rely on a single threaded motion for linear displacement. The concept is commonly contrasted with twin-screw or multi-screw designs in technical literature.

See also: Screw (propeller), Propeller, Twin-screw extruder, Single-screw extruder.