International Journal

on Marine Navigation

and Safety of Sea Transportation

Volume 1

Number 3

September 2007

327

Ship-to-ship Operations in Cold Climate

Environments

T.E. Berg

Norwegian Marine Technology Research Institute (MARINTEK), Norway

ABSTRACT: Within the Norwegian maritime cluster there is a growing interest in studies of harsh weather

marine operations. For the oil industry offshore loading is a preferred operation for production at minor

oilfields far from existing infrastructure. Safe and cost-effective production from recent oil and gas

discoveries close to the coastline of Northern Norway introduces new challenges due to cold climate

environments. At the same time increased transit of oil from northwest Russia will require increased ship-to-

ship transfer in an optimized cargo chain from the oilfields to customers in Europe and the USA.

1 BACKGROUND

Ship-to-ship cargo transfer is a critical element in

many transport chains, especially for oil and gas

products. A large part of oil export from northwest

Russia is transported by smaller tankers or rail to

Murmansk where floating storage tankers are at

anchor. Conventional oil tankers are used to carry

the oil to European or American customers. Since

2005 condensate has been transferred in sheltered

waters close to Kirkenes in northern Norway (close

to the Russian border). A number of ship owners and

agents have proposed different areas for ship-to-ship

crude oil transfer operations in sheltered waters in

fjords along the Finnmark coast.

This paper will review previous, present and

proposed applications of ship-to-ship transfer of oil

and gas in the cold climate environments of northern

Norway. The main focus will be on regulations for

and experience from operations done in sheltered

waters in this part of Norway. The Norwegian way

will be compared to traditional lightering operations

done in US waters. Other items that will be

discussed are the development of guidelines for

doing conventional lightering operations within

Norwegian territorial waters in the northern part

of the Norwegian Sea as well as the Barents Sea. At

present the Norwegian authorities only accept ship-

to-ship oil transfer in sheltered waters. Finally, the

presentation will look into the work done by Ship

Manoeuvring Simulator to develop realistic training

scenarios for emergency lightering operation under

harsh environmental conditions at sea.

2 APPLICATION OF SHIP-TO-SHIP

OPERATIONS IN THE EUROPEAN ARCTIC

2.1 Ship-to-ship oil transfer in northwest Russia

At present the only oil production in the European

Arctic takes place in northwest Russia. Due to

the seasonal ice cover in harbours east of the Kola

Peninsula small ice-strengthened tankers are used to

transfer crude oil and condensate to floating storage

and offloading vessels in Murmansk or for direct

ship-to-ship transfer operations in Norwegian

waters. Figure 1 shows the locations with existing or

planned transhipment of Russian oil for export.

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Fig. 1. Locations with existing or planned transhipment of

Russian oil for export, Bambulyak & Frantzen (2005a)

In 2003 a Russian shipping company started an

oil transport chain where smaller river tankers of the

Nefterudovoz class used the White Sea – Baltic canal

and transferred their cargo to larger ocean-going

tankers in the White Sea. Transhipment was done

offshore, close to the Osinki Islands. The ocean-

going tankers were used to transfer the oil to floating

storage and offloading ships in the Murmansk area.

The plan was to transfer some 800 000 tonnes of oil

products in the summer season in 2003 and to

increase the shipment to 1500 000 tonnes in 2004,

Bambulyak & Frantzen (2005b). The first transfer

was made on June 24

2003. On September 1

an accident took place during the approach and

mooring phase of the lightering operation. The small

river tanker had steel-to-steel contact with the ocean-

going tanker resulting in a hull plating crack on

the river tanker. It is estimated that a spill of some

20 tonnes of M-100 fuel oil took place. The transfer

operations were temporarily stopped by the

government while the consequences of the incident

were studied. On September 23

the shipping

company was allowed to restart the operation on

the condition that the shipping company prepared

and presented a “List of measurements for

the improvement of the interaction in respect of

prevention and management of emergency situations

in the area of the Onega transhipping complex”.

However, the shipping company decided to end this

operation and to deliver oil for export through other

harbours.

Since that time the Russian authorities have

forbidden offshore ship-to-ship transfer of oil

products. Instead floating storage and offloading

ships have been integrated as elements in the export

chain for Russian oil from the Barents Region.

The first transhipment terminal RPK-1 in the Kola

Bay (location C, Figure 2) was constructed by

Murmansk Shipping Company in 2002. In August

2004 a 127 000 dwt tanker was anchored at

this offshore transhipment terminal (location D,

Figure 2) and started to operate as a Floating Storage

and Offloading (FSO) vessel. The capacity of this

terminal is 5.4 million tonnes a year. The second

offshore terminal RPK-2 was built by the White

Sea Service Company and started operation in

December 2003. It only worked as a ship-to-ship

transfer facility for 3 months. The third terminal

RPK-3 started operation in March 2004 (location E,

Figure 2). The FSO is Belokamenka, a converted old

VLCC. The capacity of this export facility is

approximately 3 million tonnes crude oil annually.

The present operational capability of the vessel

is 5 million tonnes of oil a year. This capability

can be increased to 10 million tonnes when needed.

This vessel is an important element of the export

chain for crude oil to Europe and also plays an

increasing part in oil export to US west coast.

A fourth terminal is located in the Severomorsk

District, planned capacity is 2.5 million tonnes oil

annually (location F, Figure 2).

Fig. 2. Existing and planned oil terminals in Murmansk and

the Kola Bay, Bambulyak & Frantzen, 2005a

The production from Prirazlomnoye has been

delayed some years, but the latest prognosis is that it

will start in 2008. Two ice-strengthened shuttle

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tankers of 70 000 dwt have been ordered. They have

been designed by Aker Arctic and are under

construction at Admirality Yard in St. Petersburg.

These vessels will transfer the oil to Murmansk for

delivery to the Belokamenka FSO.

2.2 Ship-to-ship transfer in northern Norway

During the last few years a number of companies

have evaluated possible ship-to-ship transfer

operations in northern part of Norway. To reduce the

sailing distance for ice-strengthened vessels,

sheltered sites along the Finnmark coast have been

in focus. Bøkfjorden close to Kirkenes has been

proposed by different companies. In 2002 a test ship-

to-ship transfer was done, three Lukoil tankers of

approximately 15 000 dwt transferred crude oil to a

45 000 dwt tanker.

A major Norwegian ship owner worked for some

years to establish a permanent FSO unit in

Bøkfjorden. The varying governmental requirements

introduced during their preliminary investigation

together with protests from environmental protection

non governmental organizations (NGOs) made the

shipping company freeze further work. Towards the

end of 2005, another company, Kirkenes Transit,

obtained permission to perform up to 25 gas

condensate transfers in Bøkfjorden. Figure 3 shows

MT Perserverance performing a STS operation during

the winter season where there is thin ice in the

operational area. The permission has later been

withdrawn and the company has moved this

operation to the west and is now doing it close to

North Cape in Sarnesfjorden.

Fig. 3. Ship-to-ship transfer of gas condensate in Bøkfjorden

3 NORWEGIAN AUTHORITIES AND STS

OPERATIONS

3.1 The Norwegian view on ship-to-ship transfers

in northern waters

The Norwegian authorities have introduced a strict

view towards applications for planned STS

operations. At present their policy is that such

operations have to be done in sheltered coastal

waters. Different regulations are applied for short-

term and permanent operations. Different

governmental institutions and non-governmental

environmental protection organizations have had

hard discussions on safety aspects and the risk of oil

pollution in the vulnerable coastal regions in

northern waters resulting from errors made during

STS operations. In late 2006, the Norwegian

Pollution Control Authority withdrew their

permission to perform STS gas condensate transfer

in Bøkfjorden. The reason for this decision was the

status of the fjord as a national salmon fjord, lacking

knowledge of the salmon and its vulnerability for oil

pollution and uncertainty about how the operations

would influence the sea bird population.

3.2 Norwegian Coastal Administration – guidelines

for STS operations in sheltered waters

In discussions with representatives of the Norwegian

Coastal Administration it has been stated that at

present they will only allow ship-to-ship oil and gas

condensate operations in sheltered coastal waters.

There is presently no official operational guideline

for STS operations in Norwegian waters. The

operators have to develop their own operational

guidelines which must be approved by different

governmental authorities before an operational permit

is issued. In general, these guidelines will be based on

OCIMF’s transfer guide, OCIMF, 2005. In the STS

operations pilots will bring the vessels together.

The increased number of requests for permits to

perform STS operations will probably result in the

development of a template for preparing operational

guidelines for STS operations in sheltered waters. In

addition it will be of interest to look into weather

windows for at-sea STS operations. Operational

limits for lightering operations have been developed

by US Coast Guard, USCG, 2006. The special

conditions for cold climate operations must be

reflected in future guidelines for Arctic STS

operations. Specific parameters of interest will be

ambient temperature, risk for atmospheric icing and

the fast changes in weather conditions connected to

development and motion of polar lows. The

Norwegian Meteorological Office has stated that

there is a need for improved weather forecasts for

330

the Barents Sea when oil and gas activities expand.

More observations and better quality are a must for

the development and validation of improved

forecasts. One study has shown that by using a high

resolution atmospheric model (10 x 10 km grid) it

has been possible to describe the development and

motion of polar lows, Norwegian Meteorological

Institute, 2005. Figure 4 shows the observed polar

lows for 1999 – 2004.

Aug. Sept. Oct. Nov. Dec. Jan. Feb. Mar. Apr. May

Monthly distribution of polar lows 1999 - 2004

Fig. 4. Monthly distribution of polar lows (1999 – 2004),

prepared by Norwegian Meteorological Institute

From a governmental point of view there

is a need for further study of risk levels for at-sea

STS operations. Within other ongoing projects

MARINTEK has collected some knowledge on

accident rates and spill size for lightering operations

in the Gulf of Mexico and at other locations

worldwide.

This topic is of interest for the Russian and

Norwegian authorities.

3.3 Future STS operations in open sea – off the

coast of Finnmark and in the Barents Sea

As part of ongoing projects, MARINTEK is

involved in studies of both normal and abnormal

STS operations in Arctic waters. For studies of

normal operations it is of importance to define

weather windows for safe and efficient operations

as well as operational availability. Depending

on the available environmental data and operation

complexity two methods can be used for availability

studies. The first is a direct statistical evaluation

based on cumulative distributions of environment-

and response parameters. The second method applies

time-domain simulations of the different parts of

the operational sequence – approach, berthing and

mooring, cargo transfer, unmooring and unberthing

and the final separation phase.

Abnormal STS operations are the topic of an

ongoing R&D project on emergency operations in

Arctic waters, for more information visit the website

http://www.arcemop.no

One of the work packages is focused on

emergency lightering operation in harsh weather at

sea. In this case it is assumed that a large oil tanker

is disabled and that there is a hull damage which in

due time may result in a major oil spill. A ballasted

shuttle tanker has been selected as a offloader in a

scenario where emergency lightering is applied to

offload part of the oil from the disabled tanker in an

attempt reduce the stress on the hull beam and to

establish a hydrostatic balance in order to prohibit a

continuous oil spill from a damaged tank. The

reason for the focus on this type of emergency

operation is the increased volume of oil exports from

northwest Russia and future oil production from new

fields off the coast of Finnmark (Goliat and Nucula).

From ongoing work and discussions with

different stakeholders, it has been proposed to start

an activity to investigate the possibility of common

Norwegian and Russian guidelines for oil transfer

operations. It could be based on OCIMF’s revised

guidelines OCIMF, 2005. Additions will be needed

to take care of special factors for low temperature

environments. For operations taking place in

Russian Arctic waters there will be a need to include

requirements with respect to ice

observation/management, especially if the STS

operation is to take place in open sea close to the ice

rim. Iceberg drift could be a problem in some other

possible regions for STS operations.

4 TRAINING COURSES FOR STS

OPERATIONS

The Ship Manoeuvring Simulator Centre in

Trondheim, Norway, has for more than 10 years

given dedicated training courses on lightering

operations. At present these courses cover three

levels:

1 Basic ship-to-ship operations

− This course gives an introduction to forces and

moments between ships in close proximity

− Training scenarios are based on normal

lightering operations

2 Advanced ship-to-ship operations

− The course contains operations where weather

conditions are close to limiting values for

initiating and aborting STS operations

− Other aspects are aborting the approach phase

due to different factors such as wrong

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longitudinal position, too large speed difference

etc.

− Some training scenarios are based on reported

near misses and actual incidents

3 Abnormal STS operations

− This is a special course developed for

experienced mooring masters

− Training scenarios are based on actual incident

cases and possible critical cases identified by

experienced mooring masters

− Training topics are related to different types of

emergency operations such as failures of rudder

or propulsion systems, weather problems with

wind, sea and current in different directions,

multilayer currents and how to apply rudder in

case the service ship starts to sheer when it

begins to land on the fenders.

In the ongoing Arctic Emergency Operation R&D

project studies of emergency lightering of a disabled

tanker in harsh weather has been given priority.

Possible training scenarios have been analysed,

training objectives defined and a schedule for a

possible course concept prepared. Later this year

course material will be produced and reviewed by

experienced mooring masters. In parallel SMS will

extend the present hydrodynamic ship models to

include realistic wave and interaction forces and

moments. Additional work has to be done on

the visual system as well for cargo hoses and the

modified wave field between the two vessels.

5 PAST AND PRESENT MARINTEK

ACTIVITIES CONCERNING STS

OPERATIONS

5.1 A new initiative with respect to STS operations

MARINTEK selected ship-to-ship operations as a

topic where there was need for more basic

knowledge and understanding of the hydrodynamic

phenomena resulting in interaction forces and

moments. Starting in 2003, an internal knowledge

building activity was specified. In addition to a state-

of-the art literature survey an initial computational

fluid dynamics study was performed. Skin-to-skin

distance between the vessels was varied between 4

and 8 metres in the calculations. Heading angles

between the vessels were 0 and 2 degrees. Figure 5

illustrates the calculated pressure distribution for a

heading angle of 2 degrees between the ship to be

lightered and the service ship. Another activity was a

limited model experiment to measure interaction

forces between two tankers in calm waters and

waves. In these tests the smallest separation between

the vessels equalled 9 metres skin-to-skin distance in

full scale.

Fig. 5. CFD calculation of pressure distribution on vessels

in lightering operation

In collaboration with Norwegian University of

Science and Technology (NTNU) MARINTEK’s

towing tank has been used for master’s thesis work

on interaction forces for ships performing lightering

operations in deep water. The state-of-the art review

work was continued in 2005 as part of a pre-project

to define an international cooperation project on STS

operations. As part of the pre-project MARINTEK

and NTNU arranged three international workshops

covering the topics:

− Nautical aspects of STS operations (in

Trondheim, Norway),

− Mathematical models for interaction forces (in

Tokyo, Japan, in collaboration with Tokyo

University of Marine Science and Technology),

− Experimental studies of STS operations (in Wuxi,

China, in collaboration with China Ship Scientific

Research Centre).

5.2 New collaboration activities

As an outcome of this pre-project MARINTEK and

NTNU prepared a project proposal to the Research

Council of Norway (RCN) in October 2006.

In December 2006 the proposal was approved.

An international consortium containing shipping

industry, universities and research institutes in

Norway, Belgium, Japan, China and the US is

presently updating the project plan according to a

revised budget from RCN. The 4 year R&D project

will investigate hydrodynamic and nautical aspects of

STS operations. A kick-off meeting on nautical

aspects was held in Trondheim at the end of March

2007. Here experienced navigators presented their

view on challenges related to STS operations for an

international group of scientists to help them define

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the tasks for the theoretical part of the R&D project.

One of the participating mooring masters had done

more than 500 STS operations. His statement was that

every operation was different as it was influenced by

the actual wind, sea and current conditions. In general

the workshop participants agreed that there was a

need for better understanding of the flow patterns and

pressures distributions for STS operations.

In parallel MARINTEK is taking part in another 3

year R&D project studying ship-to-ship operations in

Arctic waters. This project is owned by BW Gas and

other partners are Framo Engineering, Rolls-Royce

Marine, DNV, Gazprom and Gazflot.

Finally MARINTEK is acting as project manager

for the ongoing “Arctic Emergency Operations”

project. The project owner is Ship Manoeuvring

Simulator (Trondheim). This project has some 20

partners representing governmental bodies, oil

companies, shipping companies, research organiza-

tions and insurance companies. One of the work

packages of this project studies emergency lightering

operations in harsh weather environments (see

Section 3.3).

6 CONCLUSIONS AND RECOMMENDATIONS

Based on a series of international workshops on

ship-to-ship operations held in 2005 it was

concluded that there was a need for further work to

improve knowledge and understanding of the

hydrodynamic aspects of ship-to-ship operations.

In-depth understanding of the water flows when

two bodies move close to each other can only be

obtained through basic fluid-dynamics studies

combined with flow visualization techniques. These

methods will be used in a four year R&D project

starting in March 2007.

Sharing of experience from lightering operations

worldwide is an important activity in work to

improve existing guidelines for STS operations.

Special care must be taken to introduce additional

parameters for operations taking place in cold

climate regions.

It is proposed that a common set of guidelines

should be developed for STS operations by the

Norwegian and Russian authorities. This work

should be based on risk assessment and operational

knowledge from STS operations and done through

collaboration between the authorities, research

organizations and other relevant stakeholders.

In order to improve the safety of future STS

operations it is of importance to improve weather

forecasts in Arctic regions. Improved forecasts will

reduce the need to abort an operation due to

unexpected weather changes.

For STS operations to be done in open waters in

the Russian part of the Barents Sea there will be a

need for an ice management service.

ACKNOWLEDGEMENT

MARINTEK expresses gratitude to the Research

Council of Norway for their financial support to

the projects:

− Arctic Emergency Operations,

− KMB Investigating hydrodynamic aspect and

control systems for ship-to-ship operations,

− BIP Safe and effective ship-to-ship operations

in Arctic waters.

REFERENCES

Bambulyak A. & Frantzen B. 2005a. Oil transport in the

Barents Region. Third International Conference on “The Oil

and Gas Industry and Sustainable Development of the

Barents Region”, Murmansk, Russia, 9-11. November

2005.

Bambulyak A. & Frantzen B. 2005b. Oil transport from

the Russian part of the Barents Region, Svanhovd

Environmental Centre, Svanhovd.

Norwegian Meteorological Institute, 2005. Increased activity in

the Barents Sea - Do we know the weather conditions good

enough?, met.no info, no. 14/2005, ISSN 1503-8017, Oslo.

OCIMF, 2005. Ship to Ship Transfer Guide (Petroleum), Oil

Companies International Marine Forum, London.

US Coast Guard, 2006. Code of Federal Regulations, 33 CFR

Part 156 Subpart C, 156.320 Maximum operating conditions,

Washington. Revised June, 2006.