Feature 4 | RUSSIA
Year
Circumstances of ice navigation
With icebreaker assistance, totally
- icebreaker pilotage - towing vessel
- ice chipping around beset vessel
- collision
Without icebreaker assis- tance, totally
- unassisted navigation - being beset in ice - other circumstances
1980 1981 1982 1983 1984 1985 1986 1987 1988 1989 85
44 24 7
10 15
8 6 1
80
52 19 8
1 20 9
10 1
84
65 8 7
4 16
9 7 -
92
57 18 2
15 8
4 4 -
86
47 15 4
20 14
8 6 -
86
54 25 1
6 14
12 2 1
Table 4. Statistics (%) of circumstances of ice damage in winter navigations.
the width of navigable ice channel. One obvious variant is to use two icebreakers. Another prospective variant is the motion on the parallel course when a tanker breaks ice cover and moves ice floes in the ice canal after the icebreaker, as a result, ice resistance to the tankers motion reduces considerably. Te effective tactics for icebreaker navigation of large-capacity tankers will be developed in future. Unfortunately, accidents occur during
the winter navigation in ice conditions. Accessible and detailed statistics of accidents of vessels have existed for the past 80 years. Tis data presented in Tables 3 and 4 give us the possibility to analyse the causes and aſter effects of accidents in these conditions and it is possible to consider that the data is typical for the present situation. Vessels were listed by damage as a result
of accidents:
• disastrous damage to hull (big hole sustained as a result of a collision or ice
• dents and corrugation of outer plating of the hull with deformation of the hull
compression)
• dents of outer plating with cracks in it • holes in the outer plating
framing
• destruction of the superstructure • damage or loss of propeller blades • loss of propeller
• damage to propeller shaſt and deadwoods
groups: damage to the hull and damage to the propeller-rudder complex. Te first group is up to 80 –90 % of all accidents. Among the hull damage 60% are dents of the outer plating, 30% are dents with cracks and 10% are holes. Among the damage to the propeller-rudder complex about 60% is damage to the propeller blades, 30% is damage to the steering arrangement and 10% is damage to the deadwoods and propeller shaſts. When studying the materials presented
in Tables 1 and 2, attention is drawn to the fact that the greatest number of accidents in the case of caravan navigation takes place if the vessel rides aſter the icebreaker and when in close towing. When unassisted navigating of vessels without an icebreaker the number of accidents is considerably less; this is connected, first, with the fact that unassisted navigation in ice happens more seldom and in relatively weak ice conditions. Te number of accidents are also affected
by the area of navigation, the North Sea Route (eastern or western), season, age of vessel and other factors come into effect. However, current statistics of ice accidents do not allow for the detection of any regularity owing to insufficient volume. At the same time, these materials can be used as a pattern to assess safety of ice navigation. Summing up the above previously
• twisting of rudder. Ice damage can be divided into two
58
mentioned, it is possible to state that the gained experience of winter navigation in Russia on sea routes provides safe cargo transportation in an acceptable range.
Increasing capacity of transported oil and oil products performed by large-capacity tankers in the basin of the Baltic Sea and Arctic Seas as well as intensifying total traffic require search and development new tactics and methods of rendering icebreaker navigation of vessels for providing safe navigation. Acknowledgement: This
study was
performed in framework projects MS-GOF and RescOP co-funded by Europe Union, the Russian Federation and the Republic of Finland. NA
Authors 1. Goncharov Vadim K. Professor, Doctor of Engineering, Saint-Petersburg State Marine Technical University, Department “Ocean Technique and Marine Technology”, 3, Lotsmanskaya str., Saint-Petersburg, 190008, Russia, e-mail:
vkgonch@mail.ru. 2. Klementieva Natalia Yu. Candidate of Engineering, Krylov Shipbuilding Research Institute, Ice Basin Laboratory, 44, Moskowskoe sh., Saint-Petersburg, 196158, Russia, e-mail:
nklem@mail.ru. 3. Sazonov Kirill E. Doctor of Engineering, Krylov Shipbuilding Research Institute, Ice Basin Laboratory, 44, Moskowskoe sh., Saint-Petersburg, 196158, Russia, e-mail:
kirsaz@rambler.ru.
The Naval Architect July/August 2011 96
44 38 2
12 4
4 - -
86
56 21 2
7 14
10 4 -
78
27 41 2
8 22
20 2 -
84
23 42 3
16 16
16 - -
Average 85.7
46.9 25.1 3.8
9.9 13.9 10
4.1 1
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