AP4 on small passenger ship

In the spring 2008 we got an order for an AP4 autopilot which should be installed in Kung Sverker, a small passenger ship in Sweden 23 meter long. The ship is used as passenger ship on Gota kanal and is used for day trips between the town Motala and “Bergs slussar” daily during the summer. For bookings you can look here Kung Sverker. You can find some very nice pictures from Sweden on that site. The following was ordered:

  • Autopilot AP4
  • Constant running pump, 4,6 litre/min, 750 W
  • Joystick non follow-up for maneuvering the ship

The ship was equiped with a hydraulic steering but was very heavy to stear, that’s the reason for the joystick. The cylinder had a volume of 1 litre so the constant running pump selected was CC-14V with 750 Watt, 380 volt. It’s used both for the autopilot as well as for joystick steering.

The picture below shows the constant running pump. It is connected to the two hydraulic hoses that goes from the steering place to the cylinder.


The biggest problem with this installation was the heading compass. The ship is made of steel and that is a problems for all electronic compasses. We did some tests by placing the compass in different locations but the result was never good.

The ship had however a reflector compass with a flat top and we decided to fit a TMC pick-up on that instead. When that was installed the autopilot behaved perfectly. Note that when this was made the new ELECOM compass was not available.

KungSverker3The picture to the right shows the reflector compass that is placed on top of the wheelhouse. The cover is removed and shows how the compass looks before fitting a TMC pick-up. It was glued on directly in the middle of the compass rose.

Below we can see the steering position with joystick and AP4 installed. The ship is steered by the joystick and the old steering helms pump is only used as back up steering. This is a requirement on most commercial ships to have a back-up in case the primary steering fails. Note that the autopilot is connected to a Garmin plotter and can thus be used for waypoint steering.