TECHNICAL REQUIREMENTS FOR YEAR-ROUND BALTIC SEA TANKER TRAFFIC

Seppo LiukkonenGERMANISCHER LLOYD

ABSTRACT

The shipping of oil by tankers from the Russian oil terminals at the Baltic Sea is increasing. This makes this rather isolated sub-arctic sea area more and more important from the point of view of safe ice-going tankers. In first place the safe tanker traffic in the area all year round including the winter season is important for the Baltic Sea coastal states. Additionally, the Baltic Sea is often called also as a “laboratory” for the real Arctic and the experiences from the Baltic Sea winters can be utilised to certain extend also for Arctic tanker projects and operations.

This paper describes the ice conditions of the Baltic Sea and the requirements these ice conditions put on the ice-going tankers operating in the area. A brief overview of the tankers in the Baltic Sea traffic today is also given.

INTRODUCTION

The Baltic Sea is a rather isolated sea area of approximately 422 000 km2 in total area. It is connected to the Atlantic Ocean through the Danish Straits, through which the water of the Baltic Sea is estimated to be changed once in a period of approximately 25 years. Due to this minor exchange of water with the Atlantic Ocean and due to the several rivers discharging into the Baltic Sea the water in the Baltic Sea is less saline than the water in the oceans. The salinity of the Baltic Sea water, called as brackish water, varies from 0 % to approximately 2 %. The zero salinity can be found in the Northern part of the Bay of Bothnia and close to the Neva River in the East end of the Gulf of Finland. The highest salinity can be found in the Southern Baltic Sea. The average depth of the Baltic Sea is only 60 m with the deepest point being 450 m. There is practically no tide in the Baltic Sea and the sea currents are weak.

From the shipping point of view an essential fact of the Baltic Sea traffic is the draught limitation. The shallowness of the Danish Straits does not allow ships with draught deeper than 15.4 m to sail to the Baltic Sea. This limits the tankers useful at the Baltic Sea to the so-called “Aframax”-size, i.e., to the size of less than 150 000 tonnes in dead weight.

From the environmental point of view the IMO has named the Baltic Sea as a special sea area with several restrictions for the discharge of oil, oily water, oily waste and garbage into the sea as well for the emissions into the air. Additionally, the Helcom (Baltic Marine Environment Protection Commission) has issued several recommendations for safe shipping and protection of the marine environment at the Baltic Sea.

In addition to the features above the presence of ice is one of the most typical features characterising the shipping in the Baltic Sea. Even tough the Baltic Sea is ice-free for the biggest part of the year, at least the northernmost parts of it, namely the Bay of Bothnia and the Gulf of Finland freeze every year. In a harsh winter all coastal waters of the whole Baltic Sea can be frozen leaving a small open water area only in the middle of the Southern Baltic Sea. Thus, the vessels intended for the year-round traffic at the Baltic Sea must be designed and built for sailing in ice.

ICE CONDITIONS AT THE BALTIC SEA

All the ice in the Baltic Sea is first-year ice. Every year, actually for the biggest part of the year, there is an open-water season. Depending on the location, the ice at the Baltic Sea is appearing for 0 - 6 months during a year. The longest time with ice is of course in the north at the Bay of Bothnia. However, the almost equally long time with ice is encountered also in the easternmost end of the Gulf of Finland that due to the Russian oil terminals is an important area for tanker traffic.

The ice formation starts in the Bay of Bothnia normally in November and in the Gulf of Finland in December. The main direction of freezing is from North to south at the Bay and Gulf of Bothnia and from east to west at the Gulf of Finland. Locally the coastal waters inside the archipelago freeze first and then the ice edge extends towards the centre parts of the sea.

The maximum extend of the ice cover at the Baltic Sea is encountered statistically in March. After middle of March the ice usually starts to melt so that by the middle of May the whole Gulf of Finland and by the end of May the northernmost part of the Bay of Bothnia are usually free of ice.

The yearly variations of the extend of the ice cover, however, are big. The figure 1 below shows the maximum extends of the ice covers at the Baltic Sea in 1987 and 1989.

Fig. 1: The maximum extend of ice cover at the Baltic Sea in 1987 (left) and 1989 (right) /1/.

The maximum level ice thickness measured in the northernmost part of the Bay of Bothnia is 1.21 m /2/. In the eastern part of the Gulf of Finland the level ice can reach the thickness up to 0.80 m /3/. However, the level ice, especially the static one in the archipelago, is not the worst obstacle for the winter navigation at the Baltic Sea. A more demanding obstacle for the ships is the pressure ridges formed by the wind moving the ice fields. The thickness of such ice ridges can exceed ten meters. Thus, for normal merchant ships, even with higher ice classes, it is usually impossible to penetrate through such ice formations, but the icebreaker assistance is needed.

Another difficult situation for a merchant ship is the compressive ice field. When a strong wind tends to move the ice field against a solid object, e.g., an island or the coastline, it creates pressure in the ice field. This increases the resistance that the ship must over come, when moving in such a pressing ice field. And if the ship will be stuck in such an ice field, the wind can push the ice against the ship’s hull with such a force that can generate damages in the ship’s hull.

ICE RESTRICTIONS FOR THE VESSSELS AT THE BALTIC SEA

Depending on the severity of the ice situation the Baltic Sea coastal states set traffic restrictions for the vessel traffic into their ports during the ice season. The restrictions are given to ensure the safety of ships sailing in ice and to ensure the smoothly-running traffic to and from the ports along the icy fairways. Principles for the ice restrictions can be found e.g., in the Helcom recommendation 25/7 “Safety of Winter Navigation in the Baltic Sea Area”.

At the territorial waters of Finland the Finnish Maritime Administration (FMA) defines restrictions to the traffic to the Finnish ports during the winter. The restrictions, which theoretically are restricting only the icebreaker assistance given to

the merchant vessels, are based on the ice classes of the vessels. In Finland the basis for the ice classes of the vessels is the Finnish-Swedish Ice Class Rules (FSICR), but via a certain “table of equivalence” /4/ the ice classes given by the classification societies define also the FSICR ice class of the vessel.

Usually the traffic restrictions from the FMA are of two-partied form. The first part of the restriction defines the minimum ice class (in the form of FSICR ice classes) that the vessel must have in order to be able to get icebreaker assistance to a particular Finnish port. The second part of the restriction defines the minimum size (in tonnes of dead weight) that the ship must have in order to be assisted by an icebreaker to a certain Finnish port.

The table 1 below sets out samples of traffic restrictions given by the FMA for the Finnish ports Kemi and Hamina. Kemi is located in the northernmost tip of the Bay of Bothnia and Hamina is the easternmost Finnish port at the Gulf of Finland.

Table 1: Samples of traffic restrictions given by the FMA for Finnish ports Kemi and Hamina /5/.

Port Kemi HaminaTime Typical 94/95-03/04 2004-2005 Typical 94/95-03/04 2004-2005Dec. 1 I, II 2000Dec. 11 I, II 2000 I, II 2000Jan. 4 IA, IB 2000 I, II 2000Jan. 11 IA, IB 2000 I, II 2000 I, II 1300Jan. 18 IA, IB 2000 IA 2000 IC, II 2000Jan. 31 IA 3000 IA 2000 IC, II 2000Feb. 8 IA 3000 IA 2000 IA, IB 2000 I, II 1300Feb. 22 IA 4000 IA 2000 IA, IB 2000 IA, IB 1300Mar. 1 IA 4000 IA 3000 IA, 2000 IA, IB 1300Mar. 14 IA 4000 IA 4000 IA, 2000 IA, IB 2000Mar. 29 IA 4000 IA 4000 IA, 2000 IA, IB 2000Apr. 1 IA 4000 IA 4000 IA, IB 2000 IA, IB 1300Apr. 12 IA 4000 IA 3000 IA, IB 1300 I, II 1300Apr. 22 IA 4000 IA 3000 IA, IB 1300May 2 IA 3000 IA, IB 2000 I, II 1300May 9 IA 3000 I, II 2000May 21 I, II 2000

Even though the restrictions given by the FMA are valid for the Finnish ports only, they, however, are representative for the winter navigation at the Baltic Sea at the areas, where the ice conditions usually are most difficult. Therefore, on the basis of the traffic restrictions from the FMA (see also Table 1) it can be concluded that the FSICR ice class IA seems to be enough for a merchant vessel operating at the Baltic Sea in the winter. With this ice class, the vessel is normally assisted to the Finnish ports by Finnish icebreakers at any time of the year on condition that the size of the vessel is sufficient. The highest FSICR ice class IA Super can be considered as an ice class that ensures the icebreaker assistance for the vessel in all ice conditions independently on the size of the vessel.

OTHER REQUIREMENTS FOR TANKER OPERATING AT THE BALTIC SEA

The classic ice class rules put requirements for the strength of the hull and some components of the vessel as well as for the propulsion power of the vessel. Also for the main engine, bilge wells and ballast water tanks, some operational requirements exist. But essential features outside the classic ice class rules still are the operation of the vessel itself and its systems at low ambient temperatures. According to the Helcom recommendation 25/7 at the Baltic Sea the vessel with its systems should be designed to be operable at the outside temperature of -30°C. In addition, the forming of ice, i.e. the icing, on the ships structures is a fact hampering al kind of deck operations when sailing at low ambient temperatures. For smaller vessels the icing can even be a problem for the stability.

Fig. 2: Icing on the deck on a tanker (Photo courtesy of Neste Oil Oyj).

OIL TRANSPORT AT THE BALTIC SEA

Figure 3 below gives an overview of the ship traffic in the Baltic Sea during twelve months from July 2005 to July 2006 /6/. During that time period a total of 51 647 ships entered or left the Baltic Sea via Skaw. About 51 000 of them passed the Swedish Island Gotland and more than 37 000 entered/left the Gulf of Finland. Approximately 60-70% of the vessels were cargo vessels and 17-25% were tankers.

Fig. 3: Helcom statistics on the ship traffic at the Baltic Sea from July 2005 to July 2006 /6/.

At the Baltic Sea the tanker traffic and the oil transport have been and still is heavily increasing because of the Russian oil export from the oil terminals at the eastern Gulf

of Finland. Figure 4 below shows the Helcom statistics of the oil transport at the Baltic Sea for the time period of 2000-2005.

Fig. 4: Amount of oil in millions of tonnes transported via 11 largest oil terminals in the east Baltic (Gdansk, Klaipeda, Ventspils, Muuga, Primorsk, Porvoo, Naantali, Riga, Butinge, St. Petersburg and Kaliningrad) and via Skaw /6/.

TANKERS IN THE BALTIC SEA TRAFFIC

On the basis of oil transport statistics it is obvious that the tanker traffic in the Baltic Sea is still increasing. The essential part of the increasing oil transport is coming from the Russian oil terminals at the easternmost tip of the Gulf of Finland. This means that the increasing tanker traffic is to be increasingly realised with ice strengthened tankers.

Traditionally the oil transport to and from icy ports at the Baltic Sea, e.g. in Finland, has been carried out with small ice strengthened tankers. These tankers have been mainly product carriers from coasters up to “handy” size with the dead weight ranging from a few thousand to a few tens of thousands tonnes and with the principal dimensions of less than 150 m in length, less than 30 m in breadth and less than 10 m in draught. Typically the FSICR ice class of those vessels is IA Super, IA or IB. Figure 4 below shows a photo of such a tanker.

Fig. 5: MT “KIISLA”, a typical coaster size oil product/chemical tanker for year-round traffic to Finland, Lo.a. 139.75 m, B 21.70 m, T 9.0 m, DWT 14 750 tonnes, engine power 8 400 kW, FSICR IA Super (photo courtesy of Neste Oil Oyj).

After Russia has built the oil terminals for their crude oil export at the Gulf of Finland the crude oil carriers have also come into the picture of the tanker traffic at the Baltic Sea. For instance, the Finnish oil company Neste Oil Oyj is operating in the Baltic Sea with a few crude oil carriers, two of which are of interesting, new and innovative Double-Acting type. The Double-Acting Tanker has its stern designed for icebreaking and the bow for open-water conditions. Thus, in severe ice conditions the ship is proceeding astern and in open water ahead. Figure 6 below shows one of the Neste Oil Oyj’s Double Acting Tanker proceeding astern in ice.

Fig. 6: A Double-Acting Tanker proceeding astern in ice. The vessel has the principal dimensions Lb.p. 237.59 m, B 44.0 m, T 165.3 m, DWT appr. 106 000 tonnes, Engine power at max. 16.0 MW and the FSICR ice class IA Super (Photo courtesy of Neste Oil Oyj)

FUTURE PROSPECTS

It is expectable that the oil transport with tankers at the Baltic Sea will still increase. Furthermore, the biggest increase can be assumed to take place with the increasing oil export from the Russian oil terminals. This means either increasing number of tanker voyages or increasing size of tankers at the Baltic Sea.

The Baltic Sea, however, puts limits for the increase of the ship size. The draught limitation at the Danish Straits is 15.4 m. Thus, the increase in size must be realised by making the vessel either wider or longer. The increased length is possible, but increasing of the breadth is not so straightforward. In the ice season most of the tankers can be expected to need icebreaker assistance. The breadth of a typical Baltic Sea icebreaker is roughly 25 m. Thus, the tankers with a breadth essentially bigger than 25 m need, if not capable for independent operation in ice, some special measures from icebreakers. Either two icebreakers or some new type of icebreaker

capable to break an extremely wide channel are needed to assist such an extremely wide tanker.

With the increased oil tanker traffic also the risk of an oil spill increases. All the Baltic Sea coastal states have, of course, developed their own preparedness for the oil spills. In addition to that, at the Baltic Sea there is a Stand-By Oil Recovery Vessel System /7/ created by a Finnish company Lamor Corporation Ab together with a Danish shipowner O.W. Bunker & Trading A/S and with funding from the European Maritime Safety Agency (EMSA). The system consists of five ice classed product tankers of coaster size and two sets of portable oil spill recovery equipment, one stored at Copenhagen, Denmark and the other one at Porvoo, Finland. The idea of the system is that the vessels, which have been fitted with sufficient fixing elements for the oil recovery equipment, are normally sailing at the Baltic Sea. In case of a big oil spill one or two of the vessels will first sail to Copenhagen or Porvoo, where the oil recovery equipment will be installed on board the vessel(s), which then sail to the spill site for oil spill recovery actions.

Fig. 7: MT “KASLA”, one of the five stand-by oil recovery vessels at the Baltic Sea /7/.

The system above with the five stand-by oil recovery vessels and two recovery equipment stores is designed in first place for ice-free conditions, as is also the main part of the oil recovery equipment of the coastal states. But an oil spill can take place also during winter in ice-covered waters. In such conditions the oil spill clean-up cannot be expected to be very effective. Even though, for instance, the five vessels above have the ice class sufficient for the Baltic Sea operations, the oil recovery action itself in ice-covered water is a problem. It is a fact that an effective method or equipment for oil spill clean-up in ice-covered waters does not exist.

SUMMARY

The tankers operating in the Baltic Sea, especially in the Northern part of it, need ice strengthening. From technical point of view the FSICR ice class IA can be considered to be the sufficient level of ice strengthening for a normal tanker. When operating in difficult ice conditions, such a tanker, however, needs icebreaker assistance. If the aim is a year-round independent operation in the Baltic Sea, a higher ice class with other special solutions is needed.

It is expectable that the oil transport at the Baltic Sea still will increase. To meet this increasing demand of transport capacity either the number of tankers or the size of the tankers at the Baltic Sea will increase. For the size of the tankers the Baltic Sea, however, put restrictions. The Danish Straits limit the draught to 15.4 m. Also for the breadth of the tankers the winter navigation with icebreaker assistance puts practical limits. The Baltic Sea icebreakers have typically the breadth less than 30 m. If the tanker breadth is exceeding this essentially, extra measures to ensure the operations in ice are needed.

The oil spill at the Baltic Sea is an essential threat, especially during the ice season. Any effective method for oil spill clean-up in ice does not exist.

REFERENCES

/1/ The Baltic Sea Portal [WWW]. Reference on 26.09.2006, available at https://www.fimr.fi/en/itamerikanta/bsds/1326.html.

/2/ Kalliosaari & Seinä: Jäätalvet 1981-85 Suomen merialueilla (Ice Winters 1981-85 at the Finnish Territorial Waters), Finnish Institute of Marine Research, publication No. 254, Helsinki, Finland, 1987 (in Finnish).

/3/ Taliev & Komissarov. Special Features of Ice Conditions in the Gulf of Finland in Winter Period 2002-2003, Final Report of the 21 Baltic Sea Ice Meeting, NWAEH, St. Petersburg, Russia, 2003.

/4/ Finnish Maritime Administration, Bulletin No. 18/30.12.2005, Helsinki, 2005./5/ Finnish Maritime Administration [WWW]. Reference on 26.09.2006,

available at https://www.fma.fi/e/functions/winter_navigation/./6/ Helcom Press Release, Helsinki, Finland, 3 August 2006./7/ European Maritime Safety Agency, “Stand-by Oil Recovery Vessels for

Europe”, Information Note, 29 November 2005.