German propulsion specialist Schottel has introduced a compact submersible auxiliary thruster designed for both manned and unmanned underwater vessels. The manufacturer developed the SPJ-S unit for demanding civilian and military subsurface tasks that demand precise manoeuvring capabilities, high operational availability, and space-saving installation. According to a report by Baird Maritime, the equipment is tailored to provide reliable propulsion across varied operating depths and challenging underwater environments.
The propulsion unit incorporates a dedicated pressure compensation system designed to equalise hydrostatic pressure at the seals, supporting reliable functionality during deepwater deployments. Schottel stated that thrust generated by the thruster can be continuously adjusted through a full 360 degrees, granting underwater platforms enhanced manoeuvring control. This capability supports positioning accuracy both on the water surface and at depth, while an electrically driven impeller removes the requirement for a gearbox, delivering low-noise operation.
Unlike conventional retractable auxiliary propulsion units that require time-consuming mechanical deployment before activation, the SPJ-S provides immediate thrust without protruding external components. Baird Maritime reported that this design configuration delivers faster platform readiness whenever supplemental manoeuvring power is needed during operations. The immediate availability of auxiliary thrust reduces preparatory downtime and eliminates the mechanical complexity associated with deploying and retracting auxiliary propulsion devices underwater.
The thruster is mounted flush with the vehicle hull, which prevents any increase in hydrodynamic resistance during transit. Schottel noted that this flush-mounted construction also minimises the hazard of equipment damage should the vessel make contact with the seabed in shallow waters. Furthermore, the unit features a robust assembly that permits controlled bottoming on the seabed, allowing installation across diverse underwater platforms ranging from extra-large unmanned underwater vehicles to submarines.
