The Hydrosta hydraulic drive system is an amazing piece of kit because it automatically compensates for one, both or alternate engines driving the counter-rotating prop. It manages to feather the drive so that the engines ideal power-band is used to its most economic effect as well as drive the many other hydraulic components on JENAL including the:

• 2 pin-anchors (spud-legs)

• wheelhouse lowering/ raising mechanism

• bow hatch (forepeak) door

• mast and lifting equipment

• 2 side thrusters
  
• 13kVA generator
  
• 2 1/2" bronze bilge pump
  
• It also drives the power-assistance for the hydraulic steering system.

The picture on the top left is the hydraulic motor that transfers the engine drive to the DuoDrive prop system and on the right is the hydraulic oil tank and fluid diverter valves above. These valves were eventually repositioned in the engine room due to access problems.