Secret Scotland

If it's secret, and in Scotland…

Scotland pioneers hybrid ferries, but could it go for battery as well?

I hadn’t realised it was just over a year to the day that I had first noticed and written about the pioneering hybrid ferries had commissioned, and were to be built in our very own Scottish shipyards – Fergusons Shipbuilders of Port Glasgow to be exact.

I won’t repeat the story behind these new ferries and their operation (you may read the original post here: The hybrid ferries of CalMac are real where links are given to the manufacturers description of the concept and its operation) , other than to say the two vessels are described as the world’s first sea-going roll-on roll-off vehicle and passenger diesel-electric hybrid ferries.

The first of the two hybrid ferries was completed recently, and the 135-tonne MV Hallaig was launched from Fergusons on December 17, 2012, at 14:00. The vessel is almost 150 feet long, and can accommodate 150 passengers, 23 cars, or two heavy goods vehicles.

The launch was recorded by someone lucky enough to work at the yard, and get a privileged position:

See also: ‘Hybrid’ CalMac ferry launched from Port Glasgow

Completion for delivery into service with CalMac is expected to be completed during early 2013, with the new ferry expected to come into service on the route between Skye and Raasay next summer, following fitting out, testing and certification. Trial are expected to take place in April/May, with the handover taking place in May.

Hallaig has its own page on the excellent Ships Of CalMac web site.

So, since we appear to have a reasonably well thought out and Scottish-made hybrid ferry (and another in the pipeline) ready to go into service, why did I refer to battery operation in the title?

Battery ferries

While Scotland has its ‘world first’ as its first hybrid car ferry gets set to enter operation…

I have recently come across another ‘world first’ in the form of the first car ferry powered by a purely electric drive system, as reported by Siemens on January 9, 2013.

Working together with the Norwegian shipyard Fjellstrand, Siemens announced development of the world’s first electrically powered car ferry, known as ZeroCat. Larger than Hallaig, their 80-metre (260 foot) vessel can accommodate up to 360 passengers and 120 cars, so is not only fully electric, but in a different class, given its ability to carry so many passengers.

Battery ferry

ZeroCat battery ferry – Siemens press picture

Due to enter service in 2015, ZeroCat will serve the route between Lavik and Oppedal, across the Sognefjord. The electrically powered ferry was developed in response to a competition organized by Norway’s Ministry of Transport, and won by shipping company Norled, which was also granted a license to operate the route until 2025 as part of its prize.

Instead of the 2,000-hp diesel engine which powers the current ferry and consumes on average more than 264,000 gallons (over 1 million litres) of diesel each year, and emits around 570 tonnes of carbon dioxide (CO2) and 15 tonnes of nitrogen oxides (NO),  ZeroCat uses an 800 kW, 11 tonne battery to drives two screws. Although the battery is heavy, the completed vessel weighs only half that of a conventional catamaran ferry, as its twin hulls are fabricated in aluminium. The hulls also use a particularly slim design which increases their efficiency, and Siemens estimates that the new ferry will need only 400 kW to cruise at 10 knots.

One  critical requirements the design was required to satisfy was the need to fully charge the batteries in only 10 minutes – the time taken to turn the ferry around at each terminal. This power demand rendered conventional charging methods unsuitable, since neither port was supplied by a large enough electrical grid to deliver the required charging current.

Instead, each terminal is equipped with a high-capacity battery installation, able to be charged slowly while the ferry is en route. This means they are then ready to provide a quick “dump charge” in the 10 minute period during which the ferry is docked while it loads and unloads it cargo of passengers and cars.

Such a system would seem to be one which could be used to advantage in Scotland, where a number of short routes exist, and the ferry terminals are only a short distance apart. For example, Rhubodach/Colintraive, and Largs/Cumbrae come to mind in my own area.

These journeys are much shorter, and of lesser capacity than that given in the Norwegian example, simplifying the demands on the batteries, motors, and charging systems. The turnaround times are also somewhat longer here, allowing more relaxed charging criteria. Given the shorter routes, it should also be possible to relax the full charge requirement too, and allow such ferries to operate without having to receive a full charge at every docking.

Unfortunately, I don’t know anyone in this business now (I used to, long ago, and even worked on some ferries – no, not in the galley, but in a technical capacity), so have no idea if anything like this is even being considered for future vessels operating in Scottish waters.

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February 5, 2013 - Posted by | Civilian, Maritime, Transport | , , , , , , , , , ,

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