A-LEX – Work meeting Technology challenges

A-LEX – Work meeting
Technology challenges
Trondheim 20141211
Tor Einar Berg
Ørjan Selvik
Norsk Marinteknisk Forskningsinstitutt
Presentation abstract
• Technology challenges related to Arctic shipping could be grouped in these topics:
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Navigation and communication
Traffic surveillance
Escape, evacuation and rescue
Vessel and offshore unit design and necessary modifications for operations in Arctic waters
• This presentation focus on handling of drifting vessels to prevent total loss or
grounding
− New methods for prediction of path of drifting vessel are needed
− More knowledge on vessel flow around a drifting vessel is needed to understan how to
position the rescue tug when reparing an emergency towing line
− Installation of emergency towing gear on vessels operating in Arctic waters could ease the
work to set up a robust emergency towing system
Technology challenges
• Traffic surveillance
• Path prediction of drifting
vessel
• Operation of towing vessel
close to a drifting vessel
• Towing point on drifting
vessel
• Towing force monitoring
Kamaro towing
Traffic surveillance
• AISSAT
− One dot = 1 ship day
• NORVTS
− Surveillance of ship traffic, identify
nonconformities
− Prevent situations by being in contact
with ships and offshore units
− Act and alarm if needed
− Administer the governmental towing
resources
AISSAT-1 data showing vessels in Arctic waters
Path prediction of drifting body
Drifting body test performed by dropping dummy from KV Andenes – as part of
NTNU thesis by Øyvind Sjåstad Bech
A-LEX – calculation of drifting path of disabled vessel
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Cargo vessel designed by Rolls-Royce
Marine
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LOA:
Breadth:
Ice class
120m
20.8m
None
Bilde: http://www.rolls-royce.com
Case parameters – environmental conditions
Case: Ship with engine black-out at the Kara Gate
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Waves
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Hs 5.0m
Tp 11.0 s
Direction 90°
Pierson-Moskowitz
Wind
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Speed 20 m/s
Direction 300°
Current
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Speed 0.25 m/s
Direction 120°
Result – waves, wind and current
Drift speed ~4kn
DRIFTING TEST
Heading
1000
50
0
-1000
40
Heading [deg]
North [m]
-2000
-3000
30
-4000
20
-5000
-6000
-1000
0
1000
2000
East [m]
300010
-1000
4000
5000
0
1000
2000
Time from start of manoeuvre [sec]
ALEX2 Waves, wind and current
Ship symbols are shown every 120 seconds.
ALEX2 Waves, wind and current: Heading
ALEX2 Waves, wind and current
3000
4000
Operation of towing vessel
close to a drifting vessel
• In a number of cases tugs have been
unable to establish an emergency
towing line due to harsh weather
conditions
• In Tromsø workshop the captain of a
Norwegian Coast Guard vessel asked
for more knowledge on water motions
along a drifting vessel
• Towing vessel manoeuvrability in harsh
weather – reduce effect of thrusters
due to ventilation
KV Harstad – Kamaro towing operation
Towing point on drifting
vessel
• Only tankers about 20000 dwt are
required to have a strong point for
emergency towing
• Emergency towing systems needed for
certain types of vessels
• Where to make an emergency towing
connection on bulk carriers, passenger
or fishing vessels?
• Operational problems on steel vessels
with aluminium superstructure
Smitt brackets work to 100/200/300/400te loadings
and suit chain sizes up to 96mm. The bracket is
acritical part of an Emergency Towing System
Towing force monitoring
• Tension monitoring for towing wire
needed
− Initial system on KV Harstad was
removed prior to the Kamaro towing
− New system will be installed on KV
Harstad in the near future
• Aiviq had a tension monitoring on their
towing winch under towing of Kulluk
− Overload alarms were misunderstood
by 3rd Mate on watch
Rescue operation – prior to Kulluk grounding
Tow force monitoring – on Aiviq during Kulluk towing
IMO mandatory emergency towing system
• Mandatory towing arrangements
Since 1 January 1996 all new tankers of 20,000 dwt and above have had to be fitted
with an emergency towing arrangement fitted at either end of the ship. Existing ships
had to be fitted with such an arrangement not later than 1 January 1999.
• What about other types of vessels?
Emergency Towing System
Rapp Bomek has developed a safe, economical
emergency towing system that complies with IMO rules
for tankers above 20 000 dwt. The light compact system
is stowed on deck in a watertight compartment fixed to
the deck, with no wires, chains or ropes to get in the
way during normal operation.
The system has a relatively low weight and is as good
as maintenance free and is quick and easy to use, not
requiring any firing, hauling or fastening to the damaged
ship.
No reference to emergency towing is found in the Polar Code