Bow / Stern Thrusters

A twin propeller unit which adds a new dimension to the convenience of a bow thruster. Having two propellers supplying equal on both sides greatly increases manoeuvrability and ease of boat handling.

Made to Last
Consisting of high‐grade, durable materials, the TwinProp is made to last. The high efficiency motor supplies unrivalled thrust. The cast, balanced four‐blade propellers are exceptionally strong and highly reliable. In addition, all components of the TwinProp that come into contact with the water are made of stainless steel.

All this makes the TwinProp a piece of equipment of great technical perfection which is reflected in, amongst others; ground precision gears, special oil/water seals with stainless steel springs and a torsionflexible
rubber safety coupling with ball bearings throughout. In case of failure of one propeller the unit still allows you to manoeuvre both sides.

Superior Quality

  • All stainless steel
  • Ground precision gears
  • Special oil/water seals with stainless steel springs
  • Torsion‐flexible rubber safety coupling
  • Thin propeller blades

Easy to Install

  • Complete with operating pane & harness
  • Very compact design
  • Variable position of unit
  • Only holes need to be drilled into the tunnel
  • No electric motor, heavy duty battery or cables required


High Efficiency

  • Two symmetrical stainless steel propellers
  • Very large blade area

Low Noise Levels

  • Thin propeller blades
  • Large blade area

Technical Specification

  • 4Kw, 450—700N of thrust (45‐70Kgf)
  • Tube diameter of 185mm

This unit can be incorporated into the ARP Hydraulics Propulsion System

  1. Oil reservoir
  2. Oil cooler
  3. Oil filter
  4. Directional control valve
  5. Drive motor
  6. Thrust unit
  7. Engine
  8. Sea water pump
  1. Hydraulic pump
  2. Gear/Throttle control
  3. Hydraulic pump
  4. Directional solenoid valve
  5. Main solenoid valve
  6. Connector for thruster solenoid
  7. Electrical connector for port operation
  8. Electrical connector for starboard operation
  9. Bow Thruster

Boat Drive

Hydraulic Propulsion Drive System

The System
The system comprises of a remote mounted reservoir tank which gravity feeds a pump fitted on the rear of the main engine. This pump pushes oil through a directional control valve which directs the oil via flexible hoses to a hydraulic motor unit that drives the propeller.

The design has proven to give many years of smooth, quiet operation with minimal running costs.


Key Benefits

  • Complete versatility of layout; engine and pumps can be mounted where it is most convenient.
  • The system noise level has its own in-built safety valve which limits the maximum torque that can be transmitted providing overload
  • Overall system noise level is low due to the positioning of the engine and pump in the most convenient place and away from the boat living quarters.
  • Vibration level cuts to an absolute minimum by being able to mount the motor in complete isolation of the engine. No thrust is transferred and there is no torsional activity between the two.
  • No alignment problems with propeller shaft and engine.
  • Ideal for applications such as fishing or canal and charter boats which have continuous gear changes.
  • Simple and fool proof control of forward, neutral and reverse which is an advantage for charter fleet operators.
  • The system can be expanded to include Bow Thruster and SKVA
    Generator (depending on the engine model).

Technical Information

  • Horse power range of 10 to 85.
  • Maximum rpm of 2800rpm.
  • Maximum thrust of 10,500kgf.
  • Reservoir capacity – approximately 25 litres depending on pipe.

Motor (with coupling)

Motor (with POD unit)

  1. Oil reservoir
  2. Oil cooler
  3. Oil filter
  4. Directional control valve
  1. Drive motor
  2. Thrust unit
  3. Engine
  1. Sea water pump
  2. Oil reservoir
  3. Gear/throttle control

Hydragen 10kVA Hydraulically Driven Generator

This generator is an option which can be incorporated into the ARP Hydraulic  Propulsion System only and is not offered as a standalone unit.

Key Benefits

  • 230v – 50Hz 10kVA Generator (brushless type).
  • Generator only turns when switched on rather than all the time the engine is running.
  • No fixed engine speed required – 230v available at low RPM.
  • Can be operated while manoeuvring and operating the bow thrusters option.
  • Unit can be mounted in a remote and convenient position.
  • Low maintenance as there is no additional engine.
  • Compact and lightweight – 90kg.
  • Dimensions (mm) – L-170 x W-140 x H-430.
  • Comes complete with operating panel (start/stop) and overload protection.
  • System should be commissioned by approved installers.