A practical demonstration of what is possible when engineering starts with the vessel and its purpose.
Some are beyond use. Others are just tatty but can be saved.
At Ecomar Innovation, we wanted to find out what it really means to recover a derelict boat from the scrap heap.
We found an old Vikoma workboat being scrapped by Aberdeen Harbour. It had been used as a boom layer to collect spilled oil. The vessel was in a sorry state, but the hull was sound and it was cheap. So we bought it.
The vessel's working role dictated the energy system, propulsion arrangement and practical installation.
We developed a 45 kWh flat-form battery pack that could sit on the deck without significantly compromising how the workboat was used. The bow space housed cooling fans, low-voltage batteries and electrical connections.
A new shaft and cutlass bearings were connected to an axial-flux electric motor. The compact motor sat within the centre well of the cathedral hull, with a deep shaft angle to provide the required working pull.
The moon pool was filled and the hull remodelled back to its original cathedral form. A new wheelhouse, rubbing strakes and removable components were fabricated to suit working use and future serviceability.
We launched the boat in late summer and it worked first time. It operated at a steady 6 knots — the hull-speed limit — and was subsequently used by a major port on the south coast as a litter picker.
During a prolonged period of rain, the vessel filled with water and the electrical system was submerged for approximately three weeks. The low-voltage cables and batteries were replaced and the damage investigated.
The system was brought back into operation. The axial-flux motor was replaced as a precaution, with the original unit retained for bench testing.
The boat returned to service and completed a further three years of operation.
The project was valuable because it exposed the engineering to the same conditions that affect any working vessel.
A suitable hull does not necessarily need to be scrapped if it still has a purpose.
A properly designed electric drive can withstand real commercial use.
The energy system and propulsion must be designed around how the vessel is actually used.
Technology only delivers its potential when operators and partners are equally committed.
