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

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Lucas Bailey
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1 in the Gulf of Finland Jakub Montewka, Floris Goerlandt, Pentti Kujala Aalto University, Marine Technology ARCTIC OIL RECOVERY EXERCISE 2015 KEMI ARCTIC

2 Agenda Introduction Available data Data mining techniques Results Conclusions

3 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. Accident Analysis and Prevention, paper accepted for publication

4 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.

5 Available data Oil tankers traffic RoPax traffic Selected AIS data for the analyzed sea area for February and March 2011.

6 Available data Icebreakers traffic

7 Available data Ice conditions in Gulf of Finland Early March 2011

8 Available data Ice concentration and drift Mean ice thickness Ridge ice thickness Compressive region

9 Data mining techniques ICE + AIS data

10 Results of data mining Convoy Towing Beset in ice

11 Results of data mining

12 Results of data mining Most of the convoy operations performed in February and March 2011 performed. 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.

13 Finland Russia Results of data mining No Analyzed variable 1 FIN vs 1 RUS Distance and speed for IB and the ship, which is following IB Distance [km] Speed [kn]

14 Finland 3 Finland 1 No 3500 Results of data mining 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]

15 Results of data mining No Analyzed variable 1 FIN vs 1 RUS Distance and speed for IB and the ship, which is following IB

16 Results of data mining

Results of statistical analysis Analyzed variable 1 Distance/speed relation for IB and the ship, which is following IB No of entries Finland Russia 44102 41423 2 Distance/speed relation for IB and

17 Results of statistical analysis Analyzed variable 1 Distance/speed relation for IB and the ship, which is following IB No of entries Finland Russia Distance/speed relation for IB and the first ship in a convoy Distance/speed relation for all ships in convoy 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. Results: the null hypothesis rejected for all the analyzed cases. 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 RUS H1 H1 H1

18 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 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.

19 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.

20 in the Gulf of Finland Jakub Montewka, Floris Goerlandt, Pentti Kujala Aalto University, Marine Technology ARCTIC OIL RECOVERY EXERCISE 2015 KEMI ARCTIC

VINTERSJÖFARTSFORSKNING

STYRELSEN FÖR VINTERSJÖFARTSFORSKNING WINTER NAVIGATION RESEARCH BOARD Research Report No 84 Leena Vedenpää OBSERV OBSERVATIONS OF SHIP ICE PERFORMANCE IN THE BALTIC Winter 2012 Finnish Transport Safety