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During the past twelve months, various record-sized ferries have been delivered, and new technically innovative ones have been contracted: In May / September 2010, Ro-Pax ferries »Stena Hollandica / Britannica« (each 62,000 GT; 5,500 m truck-lanes; 1,200 passengers in 538 cabins) came into service, followed by P&O’s »Spirit of Britain« (47,600 GT; 3,746 m truck lanes; 2,000 day-passengers without cabins). Cargo ferry »Bore Sea« (25,235 GT; 2,863 m truck-lanes) was launched this February and will be delivered in April. By the change of the years 2010 / 2011 the first really »Green Ferry« was ordered by Finnish Viking Line (57,000 GT; 1,275 m truck-lanes; 2,800 passengers in 880 cabins). This luxury cruise ferry will use LNG (liquefied natural gas) as fuel and will have no marine emissions, and its aerial emissions are to be extremely low.

Ferries have been always there, since people tried to cross waters, rivers or lakes by means of floating tree-trunks[ds_preview], wooden pontoons or other kind of swimming platforms. It seems to have started with short distances across rivers and in the beginning only for few persons. Later, more and more goods, persons and most probably also rolling vehicles were swimming across even larger waterways. But what is counted as short, and what is meant as a long voyage?

Roll-on, Roll-off ferries (RoRo)

On short distance crossings, of let us say not more than an hour, the ferry is utilized mainly during daytimes, and there is really no need for any overnight accommodation, but some food and drinks should be offered to passengers being on board. Most probably, these ferries are not turning their bows or sterns for better steaming through rough waters to the opposite port. These vessels are also named train-ferries.

On medium distance crossings, typically around three to six hours, ferries are most frequently used during daytime however at least some of their crossings are done overnight, with some slow-steaming extending the trip up to eight hours, to allow the drivers to have a rest or little sleep on board. In these cases they need accommodation with cabins and cafeteria / restaurant provision to please the passengers or at least the truck-drivers.

Ro-Pax services

On longer distance crossings, typically more than 12 hours, ferries are used for night-time crossings, where the overnight capacity is determining the actual capacity constraints. These long-distance operated vessels please especially passengers to relax and have various fun and entertainment on board. Often passengers are willing to spend more money on board than only the ticket price. It is said that normally this extra income for the shipping company can reach often up to three times the price of only the ticket and a bed in a cabin.

But filling the cabins of a RoPax ferry always with enough passengers is difficult to reach all the year around. Tourists are coming on board in sufficient quantities only during main holidays, what is the case for about three months per year. In the off-seasons the ferry has to earn most of its income from rolling freight in form of trucks, trailers, coaches, export / import cars and other form of unitized freight on rolling platforms.

The service to accommodate, feed and please passenger on board ferries was extended over the years and reached its peak especially in Scandinavia till the middle of the 1990s. Comfort on board came up to cruise standard, marketing the ships as cruise ferries and later as cruise ships with a car-deck. For Scandinavian tourists wining and dining on board a ferry between e. g. Sweden and Finland became very popular due to extreme high taxes on alcohol and tobacco in both countries.

Cruise ferries

In the Baltic Sea, especially between Finland and Sweden, roll-on / roll-off-ferry (RoRo) services started around 1960 and were developed in an endless success-story till today. In the late 1950s some partner-companies started Viking Line with having always their main-office in Mariehamn, Åland Islands. On the other hand – in Finland and Sweden – other shipping companies were realizing that RoRo-car-passenger ferries would be the dominating traffic form in the future across the Baltic Sea between Finland and Sweden. Three collaborating companies decided to form a daughter company, Oy Siljavarustamo / Siljarederiet Ab. This new company started out with used ships which were not particularly well-fitted for the role they were meant for, but that was about to change when 1961 Silja took delivery of the new »Skandia«, the first purpose-built RoRo-car-passenger ferry in the northern Baltic Sea. Sister vessel »Nordia« followed a year later and the era’s giant »Fennia« in 1966.

The highest peak in comfort development was reached in the Baltic Sea and here especially on the route Helsinki-Stockholm by 1985. Åland-based Viking Line and Helsinki-based Silja Line competed hard. Viking got the nickname »Ketchup-Line« due to the red colour of the hulls of their ships and often more favourable price-offers. Silja was a little bit more stylish in their light blue and white painted and mainly larger vessels. Finally 1987 saw again the ordering of new ships for Helsinki–Stockholm route, which were announced to be the largest ferries ever, later named »Silja Serenade / Symphony« (58,376 GT each).

Silja Line’s new generation of ferries

Not revealed at that time, the new ferries had a 140 m long promenade-street running along the centre of the ship being five decks high. This innovative feature never was seen before on board a passenger ship. Today this can commonly be found on RCI’s cruise ships of »Independence of the Seas« (154,407 GT) and »Oasis of the Seas« class (225,282 GT) as well as Color Line’s cruise-ship with car-deck »Color Fantasy« class (75,027 GT). So, Silja Line seemed to have the nose in front of Viking Line in the early 1990s.

In late 1989 Wärtsilä Marine, the shipyard building Silja’s new cruise-ferries, went bankrupt, which finally led to the ships being delivered later than planned. To ensure their delivery at all, the owners of Silja had to purchase a part of new Masa-Yards established to continue shipbuilding in Wärtsilä’s former shipyards. End of 1990, »Silja Serenade« came into service and »Silja Symphony« a year later. Both ferries became a big success, although they finally had been very expensive.

Competing Viking Line tried to copy Silja’s success and ordered giant cruise ferry »Europa« (59,912 GT) at German Meyer Werft. But close to her delivery in 1993, the owner Slite within the Viking Line Group could not pay the contracted price. Consequently the yard, trying to find a new operator for their newbuilding, chartered her out to Silja. So, this ferry operator seemed to have won the competition race for this time.

On September 28, 1994, Estonian Ro-Pax-ferry »Estonia« (15,566 GT), originally delivered by German Meyer Werft as »Viking Sally« to Viking Line capsized in very bad weather on her way from Tallin to Stockholm and sank after the bow-visor and ramp broke off. Around 990 people must have been on board of which 137 were rescued alive and 94 as dead. This accident was the worst one in the Baltic Sea after World War II and influenced the design and construction of these ferries strongly. The ferry tourism reduced and minimized the income of the corresponding shipping companies for years.

In addition the year 1999 saw two big negative effects coming forward for all ferry operators, especially in Scandinavia. By the end of June 1999, tax-free sales ended on routes between EU countries, which forced ships operating between Helsinki and Stockholm to stop at Mariehamn on the Åland Islands. Although the Åland Islands joined the EU along with the rest of Finland in 1994, their autonomous status allowed them to stay outside the EU tax union and hence avoid the end of tax-free sales. For especially Silja Line, a much bigger change than the duty-free question occurred, when Bermuda-registered Sea Containers purchased the majority of the shares of Silja’s holding company Neptun Maritime.

Tallink-takeover of Silja Line

But also other influences such as the high-speed catamaran ferries and low-cost airlines made it even more difficult to attract well-paying passengers to come on board the luxurious but expensive ferries. By 2004 Sea Containers owned Silja Line entirely. The company still managed to do it well financially. However Sea Containers’ other operations were not as profitable and in late 2005 they announced their intent to give up their ferry division completely, this naturally including selling Silja Line. But this became not too easy. Finally, »Silja Serenade / Symphony« had to be rebuilt and modernized in early 2006 to make them more attractive to a potential buyer.

In May 2006, an acceptable buyer was found in Estonian Tallink Group. The SuperSeaCats sailing between Helsinki and Tallin were not included in the sale as their purchase would have given Tallink a dominant market position on the route, which would have resulted in the competition regulators of Finland and Estonia not approving the sale. As a result Sea Containers – that had barely a year ago announced their intention to give up the ferry business completely – continued operating them under the SuperSeaCat brand.

In late 2006, the land organisations of Tallink and Silja Line were reorganised in Finland so that Tallink Finland and Superfast Finland, which had been bought by Tallink too, were merged into Oyj Silja Abp., which now took care of all Finnish operations of Tallink / Silja. Shortly afterwards Oyj Silja Abp was renamed into Tallink Silja Oy. Similarly the land organisations in Sweden became Tallink Silja AB.

In July 2008, Tallink cruise ferry »Galaxy« (48,915 GT) replaced the older second-hand ferry »Silja Festival« (34,414 GT) on the route Turku–Mariehamn–Stockholm. »Galaxy« was transferred to the Swedish flag and the text Silja Line was painted on her hull sides. The Tallink logo remained on her funnel and the Navitrolla-designed livery of the ship, which differs from the livery of other Silja Line ships, was unaltered. »Silja Festival« moved to Tallink’s Stockholm–Riga service, her funnel was repainted in Tallink colours with the name Tallink on her sides. The ferry name remained as registered even after transfer.

More than 50 years Viking Line

In 1959, Baltic ferry »Viking« became the first genuine Ro-Ro-car- and passenger-ferry to begin service for Viking Line between the Finnish Mainland, Åland Islands and Sweden. On June 1, 1995, the vessel undertook its maiden voyage on the Galtby (Åland)–Mariehamn (Åland)–Gräddö (Sweden) route. The ship was owned by a newly established company, Rederi Ab Vikinglinjen, in Mariehamn. The ferry was 99 m long and had a capacity of 88 cars. One week later, the Swedish-based company Rederi AB Slite began ferry service between Simpnäs (Sweden) and Mariehamn with »Slite«, a cargo vessel converted into a ferry.

Many people viewed these ferry ventures with great scepticism, but they later realized that this was the first phase of an almost revolutionary expansion in ferry communications between the Finnish mainland, Åland and Sweden. Before the ferry epoch really began, it was quite expansive and difficult to travel the Finnish mainland, Åland and Sweden. People either had to fly or take a night-boat that made a detour to Mariehamn during its voyage between Turku and Stockholm. This was both an inconvenient and expensive trip. Taking along ones car was a problematic enterprise – cars had to be hoisted on board. This meant a major risk of damage. As for cargo, big rig truck drivers had to drive north all the way around the Baltic Sea via Haparanda when they wanted to transport freight between Stockholm and Helsinki, for example.

Today, Viking Line operates seven cruise ferries: »Rosella« (10,757 GT, built in 1980 in Turku), »Mariella« (37,860 GT, built in 1985 in Turku), »Amorella« (34,384 GT, built 1988 in Croatia), »Isabella« (35,154 GT, built in1989 in Croatia), »Cinderella« (46,398 GT, built in 1989 in Turku), »Gabriella« (35,492 GT, built in1992 in Croatia) and finally »Viking XPRS« (34,000 GT, built in 2008 in Helsinki), the youngest newly built ferry. Another ferry for the route Kapellskär-Mariehamn was ordered at a Spanish yard to be delivered in summer 2009. The working name of this newbuilding was »Viking ADCC« (All Seasons Day Cruising and Commuting). But when the yard could not deliver the ferry in time and delayed the whole contract unforeseeable longer. Viking Line cancelled this contract and is modernising the existing ferry »Rosella« till summer this year.

Troubled STX Finland

Just before Christmas last year STX Finland Oy announced that they have signed an agreement with Viking Line ABP for the construction of an environmentally friendly, new generation cruise ferry. The agreement includes an option for a sister-vessel. The contract price is about 240 mill. €. The ferry will be built at Turku shipyard to be delivered by the beginning of 2013.

This new cruise ferry will be the most environmentally friendly big passenger vessel to date. The vessel is projected to use LNG (liquefied natural gas) fuel and it has no marine emissions and its aerial emissions are extremely low. But anyhow power generation is further done by combustion engines which still produce from one part of fuel close to three parts of carbon dioxide that harms the global atmosphere. One way to overcome this problem is in all cases to save fuel as much as possible.

The ferry itself has been specially designed to operate in the delicate and shallow waters of the Finnish and Swedish archipelago. Special attention has been paid to minimise the wave forming and noise generation. The cruise ferry is about 214 m long with around 57,000 GT and can carry 2,800 passengers to be served by a crew of 200 persons. The vessel, which will be full of innovative solutions, will have 800 passenger cabins. It will have 1,275 m truck-lanes and a separate car-deck with approximately 500 m car-lanes. In addition, there will be hoistable car-decks to be used during hectic tourist summer seasons.

This contract became very important for STX Finland as Turku shipyard ran out of work after the youngest newbuilding, super-giant cruise resort ship »Allure of the Seas« (225,282 GT; see HANSA 3/2011, page 36–40) had been delivered end of October 2010 and wanted further RCI-project »Sunshine« slipped to competitor German Meyer Werft.

So, the President and CEO of STX Finland Oy, Juha Heikinheimo, explained proudly before Christmas: »The signed agreement (with Viking Line) is an indication of the competence that the Finnish shipbuilding has as a builder of innovative and highly environmentally friendly ships. I am delighted that we get the opportunity to build at Turku shipyard a cruise ferry again for our domestic shipping company Viking Line to operate between Turku and Stockholm. The design of the new ship will start immediately at Turku shipyard, and the actual building of the ship starts during fall 2011«.

Earlier this year, when STX Finland’s loss of a contract became known to build another 158,000 GT cruise ship for RCI, Heikinheimo said very worried in Finnish TV: »I am deeply concerned about the cost levels in Finland. Compared with Germany, the general cost base in Finland has increased by 15 % in the past 10 years. It is very difficult for an individual company to tackle this rise in costs, which has been more moderate in Germany than in the other Euro-zone member countries, since the turn of the millennium«.

But Heikinheimo fairly acknowledged that Meyer Werft’s originality helped it to clinch the deal with RCI. Other observers meant that RCI might have been not too pleased to cooperate with Korean clients for their future. But there remains a feeling that STX Finland might not have paid enough attention to RCI’s wishes, what a R&D chief as retired Kaj Levander always had. It was he, who developed the inside promenade arcade in the Silja Line ferries and later in the younger RCI cruise ships as well as in Color Line’s cruise ferries.

LNG-fuelled ferries for Fjord Line

In March 2010, Norwegian Fjord Line signed a contract with Bergen Group Fosen to build two new cruise ferries. The ships will be delivered in May and November 2012. Fjord Line will thus be able to offer daily departures on the service between Norwegian Bergen, Stavanger and Danish Hirtshals. Later the year, Fjord Line announced that their new cruise ferries will be part of an EU-project with the aim of utilizing LNG as fuel for seagoing vessels.

MAN Diesel & Turbo received the order to deliver the best available energy-saving propulsion plant, which is possible state-of-the-art common-rail technology. MAN will supply eight main engines type 10L32/44CR, along with six L21/31 auxiliary generating-sets and four Renk gearboxes for the two ferries to be operated by Fjord Line Danmark A/S, the Danish subsidiary of the Norwegian ferry company. The main engines could optionally be retrofitted to a dual-fuel (DF) version, once the development of the DF type has been completed.

Both ferries will have a dead-weight of 4,000 t each on 170 m length giving a capacity to accommodate up to 1,500 passengers in 300 cabins and to carry 600 vehicles or a mix of rolling cargo or trucks with cars. Ship-owner and shipyard chose the well-proven MAN 32/44 common-rail engines on account of their fuel-efficiency and minimal emissions. Hulls will be constructed by Bergen Group’s Polish partner, Stocznia Gdansk, while final completion, assembly and interior work will be carried out by Bergen Group Fosen.

The advantages with LNG are seen in zero sulphur-and particle-emissions as well as a reduction in emissions of harmful NOx gases by about 90 % as compared to conventional fuel. Further, CO2 emissions could be reduced by up to 25 %. A major challenge will be connected with the installation of additional fuel storage tanks for LNG, as the space on board is limited. LNG demands double the volume as compared to conventional fuels in order to provide the same engine power. Storage tanks with LNG also demands more space due to regulatory demand for more insulation. These factors have to be considered when the new vessels are planned and designed.

MAN’s IMO Tier II common-rail engines

At a ceremony during marine trade show SMM 2008 in Hamburg, MAN Diesel concluded a major order for the first IMO Tier II version of its new 48/60CR four stroke engine with common-rail fuel injection. The end-user of this engine was announced as P&O Ferries, Dover, UK. The contract for two giant ferries for the route Dover-Calais was placed with today’s STX Finland Rauma shipyard. These ships are anticipating the 2011 implementation of the second stage of the IMO MARPOL 73/78 Annex VI emissions regulations.

On the engine side, for each ferry MAN supplied four inline seven cylinder type 7L48/60CR main engines, each rated 7,600 kW at 500 rpm and four gen-sets based on inline seven cylinder type 7L21/31 engines, each rated 1,463 kWe at 1,000 rpm. The scope-of-supply was completed by two double-input / single-output shaft reduction gears and two controllable pitch propellers per ship. The gears were supplied by MAN subsidiary Renk AG, Augsburg, Germany, and the propellers by MAN Diesel works in Frederikshavn, Denmark.

The 48/60CR (see HANSA 11/2008, page 40) is the third and most powerful engine in the MAN Diesel four stroke range, to be equipped with common-rail fuel injection technology and at 1,200 kW per cylinder. With inline 6, 7, 8 and cylinder and 12, 14, 16 and 18 cylinder V-versions, the 48/60CR’s overall power range of 7,200-21,600 kW at 500-514 rpm ideally complements the 3,360–11,200 kW of the 32/44CR common-rail engine announced during SMM 2006 (see HANSA 10/2006, page 30–32).

MAN’s common-rail injection system is modular with pressure accumulators subdivided into a series of segments, each serving one or two cylinders. As a result, pressure fluctuations in the system are reduced and rational use made of available space. On the 48/60CR the solenoid injection control valves are located on the segmented rails and connected to standard, pressure controlled injectors. No servo assistance of injector opening is required. This arrangement keeps sensitive components away from the hot cylinder heads and promotes retrofitting, since identical injectors are used on both the 48/60B and the 48/60CR.

The rails are pressurized by a reduced number of high pressure pumps occupying the same bores as the standard injection pumps and actuated by a modified injection camshaft. The use of at least three high pressure pumps on every engine ensures that emergency operation is possible in the event of the failure of one pump.

New P&O ferries for Dover Strait

So, P&O Ferries’ »Spirit of Britain« (47,600 GT), hull no. 1367, is the vessel with the first contracted MAN 48/60CR common-rail four stroke diesel engine on board. This short-distance Ro-Pax ferry is not fitted with passenger cabins. It was delivered by STX Europe’s Rauma shipyard on January 5, 2011. Sister-ship »Spirit of France« is going to follow in September 2011. With a measurement of each 47,600 GT, both ferries will be the largest ones in the Strait of Dover by now. Nearby, on route from Dutch Hoek van Holland to British Harwich, there are operating the two largest Ro-Pax-ferries of this kind in the world, since spring and autumn 2010, Stena Line’s Superferries »Stena Hollandica / Britannica« (62,000 GT each; see HANSA 8/2010, page 40-48). They operate on a medium distance with 1,200 passengers in 538 cabins but have 5,500 m truck-lanes each. They are also powered effectively by MAN 48/60CR diesel engines.

Both P&O-ferries are each 213 m long, 31.50 m wide, having a draught of 6.55 m and a loading capacity of 3,746 m truck-lanes. In addition to space for approximately 180 freight trucks and 195 passenger cars, each vessel can accommodate 2,000 day-passengers without cabins. Both ferries have 11 decks, of which Deck 3 is the main deck with loading / unloading rolling cargo over the bow or stern. Deck height is 5.80 m. Upper deck 5 can load / unload rolling heavy cargo also via shore-side ramps on a separate level. Deck height is 5.80 m too. Deck 7 houses an additional car deck that can be reached small fixed ramps on each port- and starboard side from Deck 5.

The trip Dover-Calais takes 75 minutes for the 21 nautical miles distance. So, the passengers do not need cabins and just have time for only a short rest with probably a quick lunch. Deck 8 and 9 are the main passenger and trucker decks with family lounges, shopping arcades, bars, food court, trucker canteen, brasserie and various club lounges. On Deck 10 the crew is living topped by Deck 11 with the navigation bridge and the funnel. Technical details of the vessels are listed in a separate table.

STX Rauma shipyard is a specialist for designing and building state-of-the-art Ro-Pax ferries. The hulls of the P&O ferries have been optimised for the vessels’ specific short distance route to ensure maximum performance and good manoeuvring characteristics. The latest and most advanced technology is applied in the design and construction of these vessels. Special attention was paid to environmentally friendly and energy-efficient solutions and safety.

»Spirit of Britain« is named by the yard the first Ro-Pax ferry in the world to meet IMO’s »Safe Return to Port« requirements and comply with the requirements of the »Green Passport« of classifying society Lloyd’s Register.

Further ferry MAN 48/60CR engine contracts Daewoo Shipbuilding & Marine Engineering Co., Ltd. (DSME) of Korea, one of the world’ largest and most innovative shipyards, ordered for common-rail 12V48/60CR Tier-II propulsion engines from MAN Diesel & Turbo SE, middle of October 2010. The prime movers will power a new Ro-Pax ferry for Tunisian ship-owner COTUNAV (Compagnie Tunisienne de Navigation).

The ferry will have a capacity of 3,200 passengers and 1,060 vehicles. It will be 210 m long, 30 m wider and will measure around 56,000 GT. Besides numerous cabins the ferry will contain a shopping centre, restaurants, swimming pool and multiple entertainment facilities. Delivery is scheduled for the first half of 2012. The newbuilding will reinforce Cotunav’s existing main routes between Tunisia, Italy and France.

The 12V48/60CR engines will have an output of each 14,400 kW at 500 rpm. Both pairs of engines operate via double-input / single-output gears to two controllable-pitch propellers with 5.60 m in diameter. The ferry can reach top speeds up to 27.5 kn in order to minimize the sailing time on the long distances between Tunisia and Europe.

North-Spanish shipyard Hijos de J. Barreras in Vigo delivered Ro-Pax ferry »Volcán del Teide« (30,000 GT) to Canary Islands’ leading shipping line Naviera Armas in February this year. The ferry is powered by four MAN 7L48/60CR main engines of 4 x 8,400 kW MCR power allowing the vessel a speed of 26 kn. With an overall length of 175.70 m, a beam of 28.10 m, a draught of 5.70 m, 1,850 m truck-lanes + 300 cars, 1,500 passengers in 124 cabins with 478 beds as well as 500 reclining seats the ferry provides maximum comfort during the 702 nm and about 27 h long voyage.

Naviera Armas is currently expanding internationally and the new ferry has been assigned to the Canary Islands – Madeira – Portim o (Portugal) route. »Volcán del Teide« is the first of two such newbuildings with MAN engines that Naviera Armas ordered from Hijos de J. Barreras in 2007. The second is due to enter service during spring this year, at which point in time the shipping line will have finished a complete replacement of its fleet that began in 2003, consisting of the acquisition of seven new vessels in just seven years.

Caterpillar MaK 9M32C to power Scandlines ferries

Caterpillar Marine Power Systems was recently selected to provide combined propulsion power and systems for two newly contracted Ro-Pax ferries for Scandlines. In 2012 this shipping company will put two new ferries into service on the Gedser–Rostock route doubling more or less the current capacity. Both ships are to be built at Volkswerft Stralsund (P+S Werften GmbH) and will offer each a capacity of 460 cars or 96 trucks (1,600 m truck-lanes) as well as 1,500 passengers without cabins. The vessels will have a length overall of approx. 169 m, a beam of 24.80 m, a scantling draught of approx. 6 m with consequently 4,200 tdw deadweight.

The two ferries will each be powered by with five MaK9M32C diesel engines with common rails. Each M32C engine produces 4,500 kW at 600 rpm or 22,500 kW of total power per vessel. The engines will be optimized for smokeless operation and reduced NOx emission levels, which have to fulfil IMO II requirements.

Caterpillar initially developed their Cat Common Rail system for the M32C engine series in 2006. Container ship »Edith Maersk« (15,500 TEU), owned by A.P. Møller-Maersk A/S, utilized the first M32C auxiliary engine retrofitted with Cat Common Rails. Common rails feature electronically controlled, fully flexible injectors capable of injecting all fuels standardized according to ISO 8217 requirements, enabling optimal combustion and low emissions at all levels. Cat Common Rail can be retrofitted on the M32C engines.

Propulsion is arranged with one main engine driving a centre controllable pitch propeller with 4,500 kW and two fixed pitch propellers with 2 x 3,500 kWe as wing-thrusters. 2 x 4,300 kWe gen-sets generate the electric power needed on board with another one (1,450 kWe) working as auxiliary gen-set. There is one shaft-generator of 4,300 kWe fed by the centreline main engine and finally a 450 kWe emergency gen-set. Two bow-thrusters (2 x 1,350 kWe) with fixed pitch propellers assist during manoeuvring. Service speed is planned for 20.5 kn.

TT-Line’s »Green Bridge Concept«

For years now, German TT-Line has been implementing solutions for an environmentally sound ship operation, as far as this is economically possible. Since 1995, TT-Line has introduced four newbuildings with environmentally friendly diesel-electric propulsion systems (Green Ship) as it is used on board most newly built cruise ships today. Two of TT-Line’s new ferries are equipped with innovative diesel-electric propulsion systems using two pods..

Unlike conventional drives, where diesel engines transmit their power directly to the shaft line, diesel generators on board these four TT-Line ferries produce electric power for all the shipboard requirements just like a power station. Even the ship’s propellers are driven by two large electric motors. This has the advantage that the diesel engines can run with constant speed, which ensures always low emissions even during unfavourable operating conditions. Consequently, when running at part-load (e.g. during manoeuvring in port or estuary sailing), the diesel-electric propulsion will reduce nitrogen oxide emissions by up to 50 %. At the same time, emissions of hydrocarbon monoxide, hydrocarbons and particles are considerably reduced.

The pod drives of the two latest delivered diesel-electric ships »Peter Pan / Nils Holgersson« (36,468 GT; delivered in 2001) represent a further technical innovation. In pods, the propulsion motors and the propellers are fitted in azimuthing gondolas, which are positioned at the stern below the hull. The electric power on board is generated from 2 x MaK 8M43 (2 x 7,200 kW), 2 x MaK 7M43 (2 x 6,300 kW) and one MaK 6M32 (2,800 kW) emergency diesel engine. Compared with conventional propulsion systems, these so-called pods achieve fuel savings of up to 15 %. Consequently, climate-damaging CO2 emissions are reduced while at the same time manoeuvrability is considerably improved.

Streamlined underwater hull forms ensure low fuel consumption, resulting in lower CO2 emissions. Further energy saving is achieved through utilization of heat recovery, e.g. from the cooling water for the diesel generators or from the exhaust gases. Diesel-generator-sets can be arranged in void spaces, away from central rooms in the hull, which can be better used as cargo holds. Electric power is led through cables to extreme destinations wherever needed. Sewage is treated biologically on board. Solid waste, sludge and hazardous waste are separated and taken ashore for recycling and disposal.

»Peter Pan« and »Nils Holgersson« (36,468 GT) were built by German SSW-shipyard in 2001. Both are 190 m over all long, 29.50 m wide and have a draft of 6.22 m giving them 7,200 tdw deadweight and a loading capacity of 2,685 m truck-lanes on three decks. 744 passengers can be accommodated in 220 cabins with all together 640 berths. All together 28,391 kW power is generated by five diesel engines of which 2 x 11,000 kW are needed by the two pods as well as 2 x 2,400 kW by two bow-thrusters. The maximum speed can be 22.0 kn.

Avoidance of sulphur in fuel

In their »Green Bridge Concept« TT-Line explains the future challenge of avoiding sulphur in fuel: The most widely used fuel worldwide for ocean-going ships is a by-product of crude oil processing and therefore contains a certain proportion of sulphur derived from the crude oil. Compared with this so-called heavy fuel oil, the sulphur content of diesel oil is lower, as diesel oil is a distillate. Diesel oil is rarely used as fuel for large marine diesel engines because it is about 80 % more expensive. According to information from Det Norske Veritas Petroleum Services, the average sulphur content of all fuels used in the second half of 2007 was 3.53 % in the Middle-East and 2.62 % worldwide. There are now various techniques available that make it make it possible to reduce the sulphur content of heavy fuel oil to about 0.5 %, but not much more below that. The diesel oil used for sea transport has a maximum sulphur content of 0.1 %.

With effect from May 19, 2006, the IMO designated the Baltic Sea the world’s first marine area to be subject to tighter restrictions on the sulphur content of fuel. Within this SECA (Sulphur Emission Control Area), marine fuel must not contain more than 1.5 % sulphur. Since August 2007, the same rules also apply in the North Sea.

From January 1, 2010, new rules come into force for EU ports in addition to the IMO regulations: In all EU ports, ships at berth will only be allowed to use fuels containing no more than 0.1 % sulphur. This rule applies to vessels docked for more than two hours. As no heavy fuel oil is available with such a low sulphur content, this regulation means that ships will have to change over to a different fuel, i.e. diesel oil, for certain time. In technical terms this is not a straightforward procedure and also not without its risks.

For global shipping, the IMO is planning a long-term reduction in sulphur content to a maximum of 0.5 %. After an initial, small reduction from 4.5 % to 3.5 % with effect from 2012, all worldwide shipping apart from the North Sea and Baltic Sea has until 2025 to switch to a fuel with a maximum sulphur content of 0.5 %. This means that global shipping will continue to use heavy fuel for the time being.

The plan for the North Sea and Baltic Sea (SECAs) is quite different: a further two-stage reduction is planned, starting from the 1.5 % limit on sulphur content already in place (since 2006). From March 2010, the limit for ships in the SECAs, i.e. the North Sea and Baltic Sea, is cut to 1 %. Through its »Green Bridge Concept«, TT-Line meets already this requirement. The second stage involves a further reduction, for the SECAs, to the very low limit of 0.1 % from as early as 2015. This not only involves a further lowering of the regional sulphur limit by the relatively small amount of 0.4 %, but will also require ships to switch to a different type of fuel, resulting in considerably higher running costs.


KN