The Ronja Storm, our newest wellboat, is expected to arrive in Hobart between the 18th-20th of February.
Upon arrival she will undergo a biosecurity and customs check which will include ballast water checks.
Once cleared, she will undergo several Pilot trips then officially commence operations in Storm Bay.
The Ronja Storm has the capability to create freshwater from seawater via reverse osmosis through an on-water desalination plant (which can produce 16.8ML of freshwater per day; or over 200,000 average sized baths for humans).
Water is taken into the vessel from the sea and turned into freshwater. In addition, the water can be used up to 12 times before being treated and returned to sea (while that is possible, our processes include an inspection of water quality after four uses).
Of each intake of seawater, 50 per cent is turned into freshwater for bathing and the other 50 per cent is cleaned (following filtration) and released back into the ocean with the additional salt and mineral content from the treated seawater. This water produced by reverse osmosis (RO) is of a higher quality than water from a freshwater river, meaning a greater density of fish is able to be treated at any given time. All water used in the RO process is filtered in a three-stage process down to a particle size of five microns.
The seawater will always be returned to the same lease from which it was taken.
Discharge of ballast water
The freshwater ballast has been generated through reverse osmosis and will be certified upon arrival through Federal Department of Environment, and any discharge will be in accordance with the Commonwealth Biofouling Management Guidelines.
As with any new vessel entering Australian waters, AMSA will conduct an initial inspection (organised by DNV-GL Norway, the Class Society responsible for undertaking the survey).
The Ronja Storm is fitted with the latest power system which utilises multiple variable speed generators which adjust the number of units in operation as well as engine speed, to meet required power demand. This is achieved by generating power at 690VAC with variable frequency and converting it to DC inside the main switchboard, and transmitting it through the ship using 1,000VDC and 700VDC grids.
Electrical power is then converted back to the required AC voltage by frequency converters which control electric motor speed. As a result, the system achieves a significant reduction in fuel consumption, and noise and exhaust emissions.
The power generation and propulsion system is designed to operate at a maximum sound pressure of 35 decibels (dB) which is a reduction of 90 per cent when compared to Ronja Huon’s designed noise pressure of 45dB (the Bel scale is logarithmic so an increase of 10dB increases sound pressure by 10 times, and increase of 20dB increases it by 100 times).
To compare this with some common household white goods, the quietest dishwasher available produces 40dB and an average domestic refrigerator produces 45dB. Noise testing has been undertaken and results are available upon request.