operations in ice conditions in

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An analysis of ship convoy operations in ice conditions in

the Gulf of Finland

Jakub Montewka, Floris Goerlandt, Pentti Kujala

Aalto University, Marine Technology

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Agenda

An analysis of ship convoy operations in ice conditions in the Gulf of Finland

• Introduction

• Available data

• Data mining techniques

• Results

• Conclusions

ARCTIC OIL RECOVERY EXERCISE 2015 “KEMI ARCTIC 2015” in Finland March 24-26 2015

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Introduction

• The recent study of accident reports for winter period in the Northern Baltic Sea shows, that most of the accidents happen, when ships are navigating in convoys [1].

• Even though, the majority of the reported accidents are of minor damages to the ships involved in the accident, major consequences, including total loss, happen as well, e.g. the case of m/v RUNNER 4.

• Ships navigating in convoys, along with independent navigation, where ships are making their way through the ice alone, are considered to be the most hazardous operations in the ice covered waters of the Northern Baltic Sea, [1].

1. Valdez Banda O.A., Goerlandt F., Montewka J., Kujala P. A risk analysis of winter navigation in Finnish sea areas.

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Introduction

• To increase our understanding of the ship convoy operations carried out in the Finnish and Russian waters of the Gulf of Finland, we developed a novel database using the best available data.

• Subsequently we carried out the data mining and the statistical analysis to find whether or not there exist correlation between speed of ships in convoys and distance between them.

• There is significant uncertainty regarding this parameter, and gap exists between years of practice of IB crews and inexperienced newcomers.

Therefore our analysis aims to bridge this gap.

• According to navigators and icebreaker crew, the research towards establishing a rule of thumb would be beneficial for everybody.

• Moreover, this knowledge can be used in any further studies on risk and safety of winter navigation in the Baltic Sea.

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Oil tankers traffic RoPax traffic

Available data

Selected AIS data for the analyzed sea area for February and

March 2011.

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Icebreakers traffic

Available data

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Available data

Ice conditions in Gulf of Finland

Early March 2011

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Ice concentration and drift

Mean ice thickness

Compressive region Ridge ice thickness

Available data

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ICE + AIS data

Data mining techniques

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Results of data mining

Beset in ice Towing

Convoy

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Results of data mining

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Results of data mining

Most of the convoy operations performed in February and March 2011 performed in the Gulf of Finland.

Scenarios analyzed:

1. Distance and speed between IB and a ship following her, if there is only 1 ship.

2. Distance and speed between IB and a ship following her, if there are more ships.

3. Distance and speed between all ships in convoy.

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Results of data mining

No Analyzed variable

1 FIN vs 1 RUS Distance and speed for IB and the ship, which is following IB

Finl an d Ru ssia

Distance [km] Speed [kn]

0 1000 2000 3000 4000

0 500 1000 1500 2000 2500 3000 3500

0 5 10 15 20

0 500 1000 1500 2000 2500

1000 1500 2000 2500 3000 3500 4000 4500

200 400 600 800 1000 1200 1400

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Results of data mining

Finl an d 1 Finl an d 3

0 1000 2000 3000 4000

0 500 1000 1500 2000 2500 3000 3500

0 5 10 15 20

0 500 1000 1500 2000 2500

0 1000 2000 3000 4000 5000 6000

0 500 1000 1500 2000 2500 3000 3500

0 5 10 15 20

0 500 1000 1500 2000 2500

No Analyzed variable

1 FIN vs. 3 FIN Dist and speed for IB and the ship following her vs. Dist and speed for all ships in convoy

Distance [km] Speed [kn]

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Results of data mining

No Analyzed variable

1 FIN vs 1 RUS Distance and speed for IB and the ship, which is following IB

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Results of data mining

An analysis of ship convoy operations in ice conditions in the Gulf of Finland ARCTIC OIL RECOVERY EXERCISE 2015 “KEMI ARCTIC

2015” in Finland March 24-26 2015

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Results of statistical analysis

Analyzed variable No of entries

Finland Russia 1 Distance/speed relation for IB and the ship, which is following

IB

44102 41423 2 Distance/speed relation for IB and the first ship in a convoy 19480 44081 3 Distance/speed relation for all ships in convoy 27404 54748 Method: Two-sample Two-dimensional

Kolmogorov-Smirnov Test.

Aim: to determine whether two sets of data arise from the same or different distributions.

The null hypothesis (H0): both data sets were drawn from the same continuous distribution.

FIN 1 FIN 2 FIN 3 RUS 1 RUS 2 RUS 3

FIN 1 H1 H1 H1 - -

FIN 2 H1 H1 - H1 -

FIN 3 H1 H1 - - H1

RUS 1 H1 - - H1 H1

RUS 2 - H1 - H1 H1

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Conclusions

• The results of the analysis are shown in the form of joint probability distributions of two variables namely distance and speed for all the convoys that took place in March 2011 in the Gulf of Finland.

• The statistical analysis of the results show differences between the speed-distance distributions for ships in convoys led by Finnish and Russian icebreakers.

• The obtained distributions can:

• serve the operational purposes, acting as a rule of thumb for navigators conning their ships in convoys in ice covered waters in the Baltic Sea.

• provide an input for the risk assessment, where the focus is on the probability of collision between ships in a convoy.

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Conclusions

• The obtained distributions account for the harsh-winter conditions.

Therefore in the case of milder conditions, the shapes of the distributions may change.

• Future research shall focus on the investigation of the effect of various

ice-related and ship-related factors on the speed of ships in convoys and

the distances between those.

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