98040 More Radio Interference

More Radio Interference
Report No. 98040

MARS 98040 Yet More Radio Interference North Sea

With reference to report MARS 98018, I have also had problems with radio interference. Some years back I joined a Stand By vessel for service in the North Sea. I joined at the shipyard where she was rebuilt and fitted out with, among other things, azimuth thrusters and joystick manoeuvre system. During the first week in operation both captains were onboard to gain experience with the vessel. A few days after arriving at the oilfield we had to go under the accommodation rig to receive some stores. My colleague who was in command, decided to put both azimuth-thrusters (fore & aft) in on the joystick system but leave the main-engine out of it. He then asked me to be stand by at the main-engine controls for safety reasons. This was not due to earlier experienced problems, only to add some extra safety measures because the vessel was just out of the yard, and we did not have any previous experience with her.

However, while we were manoeuvring close to the rig and loading stores lifted down by their crane, our chief officer started using the MF/HF transmitter. This caused both azimuth-propellers to be locked in ahead position. Attempts to switch over to manual position proved impossible. But thanks to my colleague's decision to keep the main engine outside the system, and by ordering full astern, we avoided a collision with the accommodation rig. After getting a safe distance from the rig, we tried several times to use the transmitter, mostly with the same result. The problem was later rectified, but we kept a ban on usage of MF/HF transmitters while working on joystick close to rigs or vessels.