o n
In Conjunction with
^ N U S
/
/
'NUS
N U S
International Conference on Technology &
Operation of Offshore Support Vessels
2 0
- 2 1 September 2005
National University of Singapore
Republic of Singapore
-Ttie Joint Brancii ofthe Royal Institution of Naval Architects and the Institute of Marine Engineering, Science and
Technoiogy (Singapore)
M a i n S p o n s o r
CJ^JSS
Singmarine
C o - S p o n s o r s
AB»
ALST
O
N
Centre for Offshore Research & Engineering National University of Singapore
C O R E
The Joint Branch ofthe Royal Institution of Naval Architects and
the Institute of Marine Engineering, Science and Technology (Singapore) and
the Centre for Offshore Research & Engineering, National University of Singapore
Second International Conference on Technology &
Operation of Offshore Support Vessels
OSV Singapore 2007
September 2007, Singapore
Conference Website: http://www.osvsingapore.org
There is a good demand for providing a wide range of support services such as towage, anchor handling, fire fighting, pollution control measures, loadout, transportation and installation activities, and logistics support for offshore oil and gas industry.
A 2 day event comprising of technical papers presentations and an experts'panel discussion, the conference will provide a platform for designers, builders, OSV/DSV owners, operators, drilling contractors, installation contractors to present and discuss future needs and challenges, as the search for hydrocarbons moves into deeper waters.
The conference will consider a wide range of vessel types including Towing and anchor handling vessels, off-shore supply vessel, multi purpose support vessels, drilling tenders, accommodation barges, crew boats, crane barges, pipeline barges etc.
Technical papers are invited on the following areas: • Design & Build
• Future Operational Needs of OSV/SV Operators, Drilling contractors
• Research & Development for specialized equipment for position keeping, underwater inspection & maintenance
• Classification & Statutory requirements
• Logistic Economics for deep water ofl'shore support services • Patrolling & security of offshore assets
• Installation and maintenance of FPSO moorings • Future Innovative Technology
Contents
Preface 2 ^
Organising Commitee 3
General Information 3
Final Programme 4-7
Keynote Abstract 8
Plenary 9
Abstracts 10-34
Preface
The "OSV Singapore 2005" is the first international Conference of its kind to be held in Singapore. The rapid growth in offshore activities demands innovative technology and efficient operation of offshore support vessels. Therefore, this conference has been organized to^iscuss awide^view into today's research, engineering and^development related^ to OSV technology and operation.
The Joint Branch of RINA and IMarEST (Singapore) were formed in the year 2000. One o f t h e aims o f t h e branch is to promote technical activities within various maritime clusters of Singapore. The joint branch is proud to organize this conference, which marks an important milestone of OSV activities in terms of design and building of them in Singapore.
The "OSV Singapore 2005" provides an excellent opportunity for various machinery & equipment manufacturers, maritime professionals, shipyards, classification societies, regulatory bodies and academics to increase international contacts and cooperation to stimulate progress in design and production technology for higher efficiency, better economy and improved safety of offshore support vessels.
This publication, which contains all abstracts of technical papers presented at the "OSV Singapore 2005", enables all individuals and organizations an easy access to a valuable source of information.The main topics are design & safety, diesel electric propulsion, dynamic positioning, classification & statutory requirements, etc.
This conference contains the results o f t h e enthusiasm manifested, and the efforts exerted by many On behalf of the organizing committee, I would like to extend my gratitude and appreciation to the sponsors and all persons w h o have contributed to the realization of this conference. Most importantly, thanks and congratulations to all the conference presenters and session chairpersons for their outstanding contributions to the future of offshore support vessels. I would like to thank also all participants for their interest and valuable contributions in the discussions. Finally, i would also like to thank CORE (Center for Offshore Research and Engineering) for being a joint organizer of this prestigious event.
it is with a great pleasure that we present this compilation of abstracts of technical papers presented at the OSV Singapore 2005.
Eur Ing Dr. Ir. Arun Kr. Dev BSc(Eng) MSc PhD CEng CMarTech FRINA FIMarEST MSNAME
Chairman, Organizing Committee o f t h e OSV Singapore 2005 Council Member, RINA, UK
Council Member, The Joint Branch of RINA and IMarEST (Singapore) September 2005
Local Organizing
Committee
General Information
Chairman Arun Kr, Dev Co-ChairmanYoo Sang Choo
Chairman -Technical
Devashish Dutta
Chairman - Public Relation
Nicholas Koh Chairman - Social Y. Kong Leong Treasuer Colin Nelson Secretary Rasim Asgarov Conference Manager
Kok Keong Cheah
Conference
20-21 September 2005 Engineering Auditorium NUS Faculty of Engineering 9 Engineering Drive 1
Tel:(65) 68745113 Fax:(65) 68745097 Dress Code: Shirt&Tie
Optional: Post Conference Workshop "Hardware in the Loop"
22 September 2005,9am t o 12 noon EA-02-15, Engineering Auditorium Pre-registration is required
Dress Code: Casual
Optional: Technical Tour to Keppel Shipyards
22 September 2005,1.30pm t o 4 p m
Assembly Area: Engineering Auditorium Lobby Pre-registration is required
Dress Code: Casual
Conference Dinner
20 September 2005
Cocktail reception will begin at 7.00pm NUS Kent Ridge Guild House
9 Kent Ridge Drive Singapore 119241
Tel:(65) 67791811 Fax:(65) 67788095 Dress Code: Smart Casual
Conference BBQ
21 September 2005, 7.30pm Republic of Singapore Yacht Club 52 West Coast Ferry Road
Singapore 126887
Tel:(65) 67689288 Fax:(65) 67689280 Dress Code: Smart Casual
Secretariat Room
EA-01-06, Engineering Auditorium
Official Hotel
Furama RiverFront 405 HavelockRoad Singapore 169633
Final Programme
Day 1: Tuesday, 20 September 2005
8.00am Registration 8.45am Opening Ceremony
9 00am Keynote Address 8 Chair: Devashish Dutta
Offshore Support Vessels - A New Horizon
by James B. Liebertz, President & COO, American Bureau Of Shipping, Pacific Division, Singapore
Plenary Panel Discussions 9
10.30am Tea/coffee breal<
Session 1 - Design
Chair: Devashish Dutta
11.00am Paper 1 10
Bollard Pull Guarantee in terms of Propeller and Hull Design
by SverreTonheim, Scana Volda, Norway
11.30am Paper 2 / /
New Demands on Offshore Terminal Tugs
by Robert G. Allan, Robert Allan Ltd, Canada
12.00nn Paper 3 12
Tug Behaviour in Waves as Important Factor in the Operability of Offshore LNG Berthing and Offloading Operations
by Bas Buchner, Olaf Waals (MARIN) and Pieter Dierx (TU-Delft), The Netherlands 12.30pm Lunch
Session 2A - Design & Safety/Position Keeping
Chair: Choo Yoo Sang
1.30pm Paper 4 13
Assessment of Intact Stability Requirements of Offshore Supply Vessels for Safe Operation
byZafer Ayazand Dracos Vassalos,The Ship Stability Research Centre, Universities of Glasgow and Strathclyde, UK
3.00pm P a p e r y 16
Trends in Design of Liquid Handling System in Supply Vessels
by Anders Hide, Ing.Per Gjerdrum a/s (PG Marine), Norway 3.30pm Tea/coffee break
Session 2B - Design & Safety/Position Keeping
Chair: Colin Nelson
4.00pm P a p e r s 17
Is the OSV a Chemical Bomb?
by BH Wong, Ezra Marine Pte Ltd, Singapore
4.30pm Paper 9 18
Integration of Pumping Systems in Supply Vessels matching IMO Resolution A. 673 (16)
by Anders Eide, Ing. Per Gjerdrum a/s (PG Marine), Norway
5.00pm Paper 10 19
Roles of Offshore Support Vessels in Construction Activities for Oil & Gas Industry
by Ng Eng Bin, Ng Yang Nee Elsie and Donikon Fajar, WorleyParsons Pte Ltd, Singapore
5.30pm Paper 11 20
The Geometric Aspects of Ship Position Coordinates Determination Accuracy
by Andrzej Banachowicz, Maritime Academy of Gdynia / Adam Wolski, Maritime University of Szczecin, Poland
6.00pm End of Day 1
Final Programme
Day 2: Wednesday, 21 September 2005
8,45am Registration
Session 3A - Position Keeping
Chair: Olav Egeland 9,00am Paper 12
Recent Advances in Dynamic Positioning, Positioning Technology
by Colin Soanes, The Dynamic Positioning Centre, Singapore 9,30am Paper 13
Improve Operability and Safety of DP Vessels Using Hybrid Control Concept
by AsgeirSorensen, Department of Marine Technology, NTNU, Norway, SerTong Quek and Trong Dong Nguyen, Centre for Offshore Research and Engineering, NUS, Singapore
10,00am Paper 14
Using Doppler Logs for Safer DP
by R i Stephens, A,J, Meahan and J, Flint, ALSTOM Power Conversion Ltd, UK 10.30am Tea/coffee break
Session 3B - Position Keeping
Chair: Lee Kok Leong 11,00am Paper 15
Hardware-in-the-Loop Simulation for Testing of DP Vessels
by Olav Egeland, Centre for Ships and Ocean Structures, NTNU and Roger Skjetne, Marine Cybernetics AS, Norway
11,30am Paper 16
Ship Controllability Criteria and their Application for Small Vessels
by Albert Nazarov, Hull Co Ltd, Thailand 12.00nn Paper 17
Rudder System
by Mr Henning Kuhlmann, Becker Marine Systems, Germany 12,30pm Lunch
2.30pm Paper 20 29
ACERT ® Technology: How Caterpillar Engines meet Current and Future Emission Limits
by Stephen Phillips, Caterpillar Marine Asia Pacific Pte Ltd, Singapore
3.00pm Paper 21 30
Offshore Supply Vessels equipped with Voith Schneider ® Propellers
by ivo Beu, Voith Turbo Marine GmbH & Co. KG, Germany 3.30pm Tea/coffee break
Session 4B - Propulsion / Engines-NOx Control
Chair: Arun Kr Dev
4.00pm Paper 22 3/
Electric Propulsion in Ice-going Vessels
by Arto Uuskallio, ABB Marine, Finland and Alf Kare Adnanes, ABB Marine, Norway
4.30pm Paper 23 32
Electrical Propulsion Systems for Offshore Support Vessels
by ivar Andersen, Offshore & Marine ASA, Norway
5.00pm Paper 24 33
New Diesel-Electric Propulsion Concepts for OSVs
by Joachim Muller, SCHOTTEL GmbH & Co. KG, Germany
5.30pm Paper 25 34
Common Rail Diesel Fuel Injection Technology
by Klaus Deleroi, MTU Asia, Singapore 6.00pm Closing Address
End of Day 2 7.30pm Barbeque Dinner
Keynote Address
Offshore Support Vessels - A New Horizon
M r James B. L i e b e r t z
President & Chief Operating Officer, ABSPacifi^Bivision
-There could be no more appropriate venue for such a gathering than here in Singapore, the center for offshore-related construction and management in the Asian theater.
Singapore has a tradition of building OSVs beginning in the 1970s. At that time Singapore's shipbuilding and marine industry was in its infancy. But it took on the challenge of serving the emerging offshore industry in the region with a particular focus on building mobile offshore drilling units and offshore supply vessels. We all know that these activities declined in the 1980s as oil prices declined. Many well-known names did not survive the lean years.Those that did are reaping the fruits now, as demand for both MODUs and OSVs is once again very strong.
The origin of today's OSVs can be found in the Gulf of Mexico - when oil exploration moved offshore in the 1950s. Then, surplus World War il vessels, wooden fishing boats, and shrimp trawlers were used to supply offshore rigs with cement, mud, spare parts, crews, fuel and food. In 1955, Alden and John Laborde developed the first purpose-built vessel to supply offshore rigs and platforms, it featured a bow wheelhouse and a long flat afterdeck that became the standard for offshore supply vessels.The pioneers may have modeled OSVs on a pickup truck - rugged, versatile, and capable of delivering goods and people to the frontiers. The Labordes must be intensely proud today, as their innovation has done more than survive. It has become an industry standard that is an integral element o f t h e continuing search for energy resources under the world's oceans.
Today we are once again seeing an almost fevered level of offshore activity as the price of oil, and concerns over the adequacy of future supplies increase. Its impact on the OSV sector has been to create a second wave, similar to the crest o f t h e 1970s after the long trough o f t h e intervening years.
Against this backdrop, the new generation of OSVs contains many features that cater to the needs of deepwater support operations as well as emergency response.
The engineering of sorts of capabilities onto a relatively small platform is a challenge that has been met through the adoption of modern technologies, such as electric propulsion and integrated control systems.This new generation of OSVs is a far cry from the one it replaces.
If anything, the OSV of today is more than a pickup truck; it's like something outfitted for James Bond. This
conference thus piovides a valuable opportunity for an open exchange of views among the various participants in this exciting field.
Plenary Discussion Abstract
Discussing Serviceability
Objective
To begin the conference by stimulating discussion and exchange of information amongst participants on key areas of c o m m o n interest between vessel builders, operators and end users.
Panel Members
Mr Charles Foo (Chairman)
Managing Director (Special Projects)
Keppel Offstiore & Marine Ltd (Vessel Builders)
Capt Sean Dunne
Operations Manager
Tidewater Marine International (Vessel owners)
Capt Mike Meade
Managing Director
M3 Marine Pvt Ltd (Marine Consultancy)
Capt Mike Negus
Marine Manager
Noble Denton Singapore (Offstiore consultancy + surveying)
Mr Colin Nelson
Marine Operations Engineer
Transocean (Offshore dniiing contractor)
M r A K S e a h
V. P Technoiogy & Business Deveiopment ABS Pacific (Ciassification Society)
The panel discussion will be used to introduce delegates to some o f t h e issues of serviceability and operability which the conference is intended to highlight.
It is hoped that a free and open airing of views at the start o f t h e conference will act a a catalyst for debate by presenters and participants alike, and that it may serve to focus on the value o f t h e papers which will follow and stimulate free discussion on concerns of mutual interest to all attendees.
We anticipate t h a t t h e likely areas of discussion may be drawn from some o f t h e following issues:-• Are end users giving adequate feedback to the design process?
• Do vessels perform to specification throughout their service lives?
• What are the impacts of manning and maintenance on vessel performance? • Should more attention to operating costs be given at the design stage?
• Maintenance - Finding the balance between operating profit and asset longevity • Are current levels of station-keeping and manoeuvrability adequate?
• Is there a need for closer investigation of vessel performance in a variety of loading and service conditions? • Are shoreside handling and storage and cleaning facilities adequate for current and future requirements • How will the offshore industry be affected by new regulations on pollution and security?
• Is there a need for an industry initiative to scrap older tonnage? • Are current Bimco contracts needing revision?
. Would OSVs benefit from a separate IMO code, (like MODU's)
The above topics are not intended to be exclusive, and should delegates wish to raise other matters of c o m m o n interest, these should be directed to the Conference secretariat before the event or through the Chairman during the session itself
Paper 1
Bollard Pull Guarantee in terms of Propeller and Hull Design
S v e r r e T o n h e i m , B.Sc,
Sales Manager, Scana Volda
All types of towing vessels are in need of a high pulling force to carry out their operations efficiently. The focus on highest possible bollard pull is increasing. In many cases nowadays this is the only specified goal. Very often there is a demand for a bollard pull guarantee, and normally substantial penalties are involved in case the guarantee figure is not obtained.
However, the term "bollard pulT'without further definition, traditionally may have several different meanings. One can talk of the maximum (static) bollard pull, which is the initial peak figure, measured shortly afterthe full test power is reached, or the continuous (dynamic) bollard pull, which is the stabile value, sustained during at least 10-15 minutes o f t h e test.
it is also a question of power definition. Is the guarantee pull figure related to the engine MCR power, or to any degree of engine overload?
Also the terms"bollard pulf'and"bollard thrust"is sometimes used without distinction, which contribute to further confusion. In order to eliminate all misunderstanding, clear definitions, and well defined test codes, describing the full scale test conditions, have been established many years ago.
Generally the bollard thrust can be approximated based on published std. data from relevant propeller model series. However, such model data is so called "Open water model data", which means they are valid for homogenous parallel flow, model scale.
The definition of bollard THRUST is the total axial force created by the propeller and the nozzle, in an open water condition (no hull present) at zero flow velocity.The thrust deduction factor can be estimated by evaluation of hull lines and propeller / nozzle / rudder arrangement, together with experience from similar ships.
When it comes to a formal "Bollard pull guarantee", this term calls fora higher degree of reliability. Bollard pull guarantees are normally required for a specified figure, which shall be obtained during the full scale bollard pull test, required for the official ship certificate.
Where model test is not carried out, a bollard pull guarantee can be considered based on hydrostatic hull data only, if the required guarantee figure is found obtainable without reasonable doubt.
There should be a c o m m o n understanding in the market on which criteria should be valid for giving a bollard pull guarantee.This would make it possible for ship designers and shipyards to prepare for the necessary documentation and tests at an early stage. On this basis it would be possible to compare guarantees from different suppliers and it would also minimise the risk to give these guarantees.
Paper 2
New Demands on Offshore Terminal Tugs
Robert G. Allan, P. E n g . ,
Robert Allan Ltd, Vancouver, Canada
Key words: tug, offshore, sea-state, motions, performance
The advent of oil drilling in deeper water, and the development of major oil and LNG terminals in areas exposed t o more severe weather than has previously been the norm places significant demands on the tugboats used to serve these terminals and offshore operations. Users are rightly demanding that the tugs be able to offer their advertised thrust in increasingly severe sea-states, but there is nothing in the public domain to enable a prediction of how tug performance degrades with sea-state. Nor is there any information available to assess how different designs of tugs behave in the same sea-state.
Over the past 18 months the author's company has conducted a significant body of research into these various factors, including comparative motions response of t w o tugs of similar size but of quite different hull forms, and the variation of t o w line connection forces between tug and ship as a function of separation, relative t u g -ship orientation, and tug-wave orientation. This paper represents, to the best of our knowledge, the first public distribution of such critical information concerning tug behaviour in waves.
The paper is summarized by a presentation of a new offshore terminal/escort tug design developed by Robert Allan Ltd. for service at a major Middle Eastern oil terminal.
Paper 3
Tug Behaviour in Waves as Important Factor in the Operability of Offshore
LNG Berthing and Offloading Operations
Bas B u c h n e r ,
Maritime Researcil Institute Netherlands (MARIN)
O l a f W a a l s ,
Maritime Research institute Netherlands (MARIN)
Pieter D i e r x ,
Deift University of Technology (TU Deift)
Key words: offshore, tugs, motions in waves, LNG, offloading
For future offshore LNG terminals tugs are planned to assist LNG carriers during berthing and offloading operations. A model test study was carried out to better understand the tug behaviour in waves and to make a first step in the quantification o f t h e related weather limits. Scale 1:35 model tests were performed in the two important'modes'of a tug during this type of operation: the'push'mode and the'puH'mode. Realistic weather conditions were used and the tugs were working at the unshielded and shielded sides o f t h e LNG carrier.
Based on the results presented in this paper, it can be concluded that the motions of tugs in waves are significant, even in wave conditions that are considered to be mild for the berthing and offloading LNG carriers. The resulting push or pull loads may hamper these tug operations significantly Special measures are necessary to take this behaviour into account in tug design, LNG carrier design and development of operational procedures and equipment.The paper gives insight in the typical tug behaviour in different weather conditions.
Paper 4
Assessment of Intact Stability Requirements of Offshore Supply Vessels
for Safe Operation
Zafer Ayaz,
The Ship Stability Research Centre, Department of Naval Architecture and Marine Engineenng, Universities of Glasgow and Strathclyde, UK
D r a c o s Vassalos,
The Ship Stability Research Centre, Department of Naval Architecture and Mahne Engineenng, Universities of Glasgow and Strathclyde, UK
Key words; offshore, supply, stability, operation
Intact stability requirements for the design and operation of offshore supply vessels are subject to the international codes and regulations issued by organizations such as IMO (Code on Intact Stability), classification societies as well as national and regional safety agencies. However, currently the design of this type of vessels is largely re-evaluated due to the expansion in size as well as the novel developments in engine, propulsion and control systems. This is mainly the result of significant changes in traditional operational areas due to rapid developments in deep waters exploration and exploitation, platforms, equipment etc.. .Therefore, supply vessels are due for a major overhaul concerning rigorous assessment of existing intact stability rules in terms o f t h e ship design and operation factors.
Within the above framework, the paper presents a review of current codes on intact stability and their comparison against each other in terms of important design and operational parameters. This is followed by the presentation of the new developments in intact stability using probabilistic and deterministic methodologies to address the physics o f t h e problem and to encompass the dynamic behaviour observed in the actual operation of offshore supply vessels in a way that the ensuing instrument is amenable to designers, operators and regulators, aspects which are usually neglected or covered too broadly in the many codes currently available.This includes the new developments in engine, propulsion and control systems and their possible effects on the intact stability requirements.
Finally, conclusions are drawn on the applicability o f t h e current intact stability rules and recommendations are made on their suitability for safe operation of new and future generation of offshore supply vessels.
Paper 5
Bridge System Safety: NAUT-OSV
Hans R a m s v i k
Det Norske Veritas (DNV)
K e y w o r d s : offshore, support, OSV, nautical, operation
Approxinnately 50% of all shipping accidents at sea are nautical accidents. The term Bridge System is introduced as alternative way of thinking when addressing nautical accidents (grounding, collision and contact accidents) which often are addressed as human errors.
Human Error is the most used term in the marine terminology when it comes to explaining accidents and especially accidents that have the origin on the navigating bridge. 80% o f t h e nautical accidents are said to be caused by human error. The paper will introduce the term bridge system in orderto better address nautical operations and thereby reduce the number of human errors.
A bridge system shall ensure that the vessel is navigated and manoeuvred safely from port to offshore installation and back to port, by using correct course and speed in relation to waters and traffic, and consists of 4 main parts: The Mariner, the technical system, the human-machine interface and operational procedures. Result from a joint
industry project which was established in order to address the bridge system onboard offshore service vessels will be presented. The project had participants from oil companies, ship owners and regulators. Navigators were heavily involved during the various stages o f t h e project.
The end report from the project which is available for free download from Internet can be used as a guideline for specification, design and verification by ship owners, yards, equipment manufacturers, charterers and regulatory bodies.
Paper 6
Modern Offshore Support Vessels: Class and Statutory Perspectives
A h m a d S a r t h y ^
Manager, Ship/Offshore Structure & Statutes, American Bureau ofSliipping, Singapore
H a m J o o n Lok,
Senior Engineer, Sliip/01Tsliore Engineering Systems, American Bureau of Shipping, Singapore
Key words: offshore, support, supply, towing, fire fighting, dynamic positioning
The world today has about 4000 offshore support vessels of various types. While statistical data are not very precise, there appears to be more than 250 under construction at present. The trend is towards a) bigger vessels with higher hp (10,000 hp and greater) and bollard pull (150 -200 ton) and b) offshore supply vessels with fire fighting and dynamic positioning (DP) capabilities.These m.odern vessels, intending for fleet replacement on the one hand, and to meet the more demanding needs of deeper water operations on the other, are of much improved designs and packed with multi-functional capabilities.
This paper outlines first the basic requirements of offshore support vessels from classification perspectives, followed by provisions for specialized functions and capabilities, such as fire fighting and dynamic positioning. Current and impending statutory requirements applicable to this vessel type are also discussed. Some modern support vessel design characteristics are given with a view to illustrate the design trends and regulatory impacts.
Paper 7
Trends in Design of Liquid Handling Systems in Supply Vessels.
A n d e r s Eide,
Technical Manager of Ing. Per Gjerdrum a/s (PG Marine).
Brief
Covers tine topics:
- Revue of development in supply vessel pumping systems. - positive displacement pumps versus centrifugal pumps - hydraulic and electric mud agitators,
- mud and mud tank cleaning systems.
Briefly how the pumping systems developed from general "marine designed" industrial pumps to designed application pumps. Why and where can special designs be justified?
Why use displacement pumps instead of simple centrifugal pumps?
The reason behind introduction of hydraulic driven pumps, frequency converter operation etc.
The development of specialized mud systems from early Centrifugal pumps with circulation in ordinary cargo tanks to Specialized systems with eccentric screw pumps, centrifugal pumps, agitators and advanced cleaning systems Similarities and differences of hydraulic and electric mud agitators comes as a part of this section.
Conclusion
In the last t w o decencies we first had a rapid increase in high volume, high delivery head . complicated and highly advanced automated pumping systems with vessels designed to serve a "World Wide" market. These requirements remain, but parallel we have a increasing trend to supply a diversity of tailor-made vessels for specific markets like; Arctic operation, Brazil specification. East Asia operation. West Africa operation, high degree of automatisation as well as mainly manual control.
Paper 8
Is the OSV a Chemical Bomb?
B H W o n g ,
Technical Director, EZRA Marine Services Pte Ltd, Singapore 449269
Key words: offshore, support, supply, hazardous, acids, rioxious
Offshore Supply Vessel (OSV), defined by IMO, means a vessel which is used for the transportation of stores, materials, equipment or personnel to, from and between offshore installations.
Charterers and operators of OSVs and Rigs are not well-versed with the requirements for the transportation and containment of hazardous and noxious liquid substances in the OSV. Masters of OSV should not accept the loading of any cargo unsafe for handling or improperly documented.
Responsibility for ensuring that cargoes are suitable for carriage rests with operator, shipper or owner o f t h e cargoes. All parties should be aware o f t h e IMO Codes and conventions for the safe carriage ofthese cargoes.
Judging from the few OSVs that comply to carry hazardous or pollutive cargoes, it is concluded that since the adoption of IMO Res. A.673 (16) in 1990, OSV operators and owners have been reluctant to modif/ or build the cargo tanks in accordance with the IMO Resolution.
The British Marine Guidance Note (MGN) has noted that Offshore Installation Managers (OlMs) are not declaring the back loads correctly and OSV Masters may be loading dangerous cargoes in the tanks.
Paper 9
Integration of pumping systems in supply vessels matching
mo RESOLUTION A. 673(16).
Guidelines for the transport and handling of limited amounts of Hazardous and
Noxious liquid substances in bulk on offshore support vessel
A n d e r s Eide,
Technical Manager of Ing. Per Gjerdrum a/s (PG Mahne).
Brief
Why transporting dangerous liquids in supply vessels.
The developing requirement of such facilities in supply vessels, Main and typical cargoes:
Methanol,
Polymerized chemicals.
Dangerous backloads, slops, Oil Recovery. Risk assessment.
The paper will take you through a brief history of increase in demand for different bulk transport and pumping solutions under this description.
DNV claim to be the first to make a notification for this type of cargoes and give the designer a recipe how t o make the tank and pumping arrangement.
Since 1998 PG Marine have had enquiries for more demanding cargoes than Methanol and Oil Recovery, but "under covers" like "Special Cargo" "Wax Inhibitor", "Slop", "Hose Handling Oil Recovery" etc. etc..
Both the development of more sophisticated p u m p solutions and a risk assessment and a pollution assessment of the solution have then been a part of our supply.
Conclusion
Ship-owners and designers should at an early stage in their projects take a decision if they shall include cargo capacities w h o fulfill IMO A.673(16).This will make it easier to implement this kind of systems and profit from this type of systems when it is asked for.
Paper 10
Roles of Offshore Support Vessels in Construction Activities
for Oil & Gas Industry
N g Eng Bin (FIMarEST), N g Yang Nee Elsie, D o n i k o n Fajar
l ^ / o r / e y Parsons Pte Limited, Singapore
This paper seeks to provide basic information on the use of offshore support vessels (OSVs) in the construction activities typical in the oil & gas industry, it explains how OSVs are used in offshore pipelaying and other offshore installation activities, such as jacket and deck installation.The paper will discuss conventional pipelaying operations as well as unconventional pipelaying operations, such as surface t o w installation, bottom t o w operation, controlled depth t o w operation, etc.The paper also provides basic information on conventional pipelaying, offshore platform transportation and installation, and other types of construction. The intend o f t h e paper is to highlight the
importance of marine vessels in offshore construction.
It is hoped that the information provided will help designers and fabricators understand the various uses o f t h e OSVs in the offshore construction field, and help innovate further improvements in their design.
Paper 11
The Geometric Aspect of Ship Position
Coordinates Determination Accuracy
A n d r z e j B a n a c h o w i c z prof, d r
Maritime Academy of Gdynia - POLAND
A d a m W o l s k i prof, d r
Maritime University of Szczecin - POLAND
The article presents generalised concepts of geometrical factors of a navigational system. The modern process of navigation is described in a four-dimensional space - three geometric dimensions and time. For this reason both the description and analysis of navigational systems should be performed in the same space. The traditional geometric factor of the land-based radionavigational system was generalised to include the factors GDOP, PDOR HDOR VDOP and TDOP f o r t h e needs o f t h e accuracy analysis of a GPS system. These terms are related to the so-called geometry of navigational system - through mutually related positions of gradients of navigational functions determining position lines (hyperplanes).They are connected with non-linear regression through a probabilistic relation between the measured navigational parameters. Consequently, the concept of geometric factors in the process of navigational parameters estimation can be also extended to include a larger number of dimensions appropriate for the state vector.
Paper 12
Recent Advances in Dynamic Positioning, Position Measuring Technology
C o l i n Soanes,
The Dynamic Positioning Centre, Singapore
K e y w o r d s : offshore, Dynamic Positioning (DP), Position Reference System (PRS), Acoustic, satellite navigation,
(D)GPS, Laser,Taut wire. Radar reference. Radio reference system
Dynamic Positioning has been used in the offshore industry since the early 1960s, the technology required to allow all season, all weather operations is always moving forward.This paper will deal with some o f t h e latest advances in PRS technology
To control a vessels position, the position must first be measured, historically Acoustic,Taut wire and Radio references were used.This placed severe limitation on Operations, the introduction o f t h e GPS satellite navigation system gave the offshore industry more flexibility, but this system has limitations caused by atmospheric interference and line of sight interruptions, new satellite systems are available that reduce these effects. New Laser and Radar technology complements the advances in satellite technology giving offshore DP user greater flexibility in PRS. As operations move into deeper water, new Acoustics position systems have been designed that work in deeper water and allow multiple users. New wideband technology reduces inference.
In this paper I will discuss the recent advances in positioning technology that allow the offshore DP user to take full advantage of DP systems to enable safer offshore DP operation. I wiil cover advances Satellite, Acoustic, Laser, Taut Wire, and Radar systems
Paper 13
Improve Operability and Safety of DP Vessels Using
Hybrid Control Concept
A s g e i r J. S o r e n s e n ' , S e r T o n g Q u e k ^ a n d T r o n g D o n g N g u y e n ^
'Department of Marine Technology, NTNU, N-7491 Trondheim, Norway ^Department of Civil Engineenng, NUS, I Engineenng Drive 2, Singapore.
In this paper new control system architecture for dynamic positioning and transit operations of marine vessels is proposed.The proposed control system architecture is based on hybrid control using estimator-based supervisory control in conjunction with operator initiated commands. The hybrid control system consist of continues state multi-controller and discrete state logic that allows smooth switching between the various multi-controllers for station keeping and automatic sailing. The concept of hybrid control is also used to automatically switch between appropriate designed controllers handling normal operational conditions to extreme situations such as severe seas and possible failure situations. By this it will be possible to extend the vessel operability subject to harsh environments and increase the safety in the marine operations by increased fault tolerance, in the paper demonstrating examples of DP control and low level thruster and propulsion control on offshore service vessels will be shown.
Paper 14
Using Doppler Logs for Safer DP
Dr RI S t e p h e n s / A . J. M e a h a n / J . Flint
ALSTOM Power Conversion Ltd, Rugby, Ui<
The move to deeper and deeper water has presented major problems for operators of DP vessels as the available position measuring equipment (PIVIE) is stretched to its limits. Acoustic systems become noisier with longer update periods, taut-wire systems become untenable. More and more reliance is placed upon GPS and DGPS. This has presented problems when disturbances in the ionosphere have disabled GPS systems.
There is a need for alternative PMEs that are independent o f t h e traditional PMEs. The use of inertial systems has faltered because the errors in position increase with the square of time. They are therefore reliant on regular updates from other PMEs.
The alternative presented in this paper is to incorporate velocity measurements from Doppler logs which are utilised within a Kalman filter to maintain position. The Kalman filter formulation allows the Doppler to be used either in conjunction with other PMEs (e.g. to fill in the gaps of a slowly updating acoustic system, or to assist in the reduction of noise) or alone when all other PMEs fail. This latter use could prove crucial in an emergency, and unlike inertial systems, the DP can continue safely for many minutes with velocity measurements only
The paper describes the motivation behind the use of Doppler logs in DP and the advantages. It shows how the velocity measurements are used in the Kalman filter estimates of position and velocity. It also presents results of simulation studies as well as data from a real vessel.
Paper 15
Hardware-ln-the-Loop Simulation for Testing of DP Vessels
Olav E g e l a n d
Norwegian University of Science and Technology Centre for Ships and Ocean Structures
Otto Nielsens veg 10, NO-7491 Trondheim, Norway Olav.Egeland@ntnu.no
Roger S k j e t n e
Mahne Cybernetics AS
P.O. Box4607, NO-7451 Trondheim, Norway rs@marinecybernetics.com
K e y w o r d s : Simulation, hardware-in-the-Loop, dynamic positioning
Digital control systems are important for the performance and safety of modern ships, and the current trend is that many new innovations for ships are related to control systems. Controllers are becoming more complicated, and the different control systems are becoming closely integrated. As a consequence of this, there is a need for new testing methods and test technology that will facilitate verification and validation of maritime control systems.
In this paper the use of Hardware-ln-the-Loop (HIL) testing for verification and validation of DP vessels is discussed. In HIL testing the control system is connected to real-time simulator instead o f t h e ship. This allows for extensive testing o f t h e control system before commissioning and sea-trials. Moreover, the use of HIL-testing makes it possible to test the control system under test conditions that may compromise the safety of ship and crew, like high sea-states in combination with possible black-out situations in the power system.
Paper 16
Ship Controllability criteria and tiieir Application
for Small Vessels
A l b e r t N A Z A R O V
Naval Architect, Ph.D., MRINA, MSNAME Project Supervisor,
Hull Co Ltd' 108/1 M-5 Na-Klue, Banglamung, Chonbuh, 20150, THAILAND E-mail: nydesign@yandex.ru
Analysis of contemporary controllability criteria is provided, classification societies and IMO requirements are discussed and compared. It is stated that three main types of requirements exist, regulating controllability in indirect and direct way. First type are simple requirements for rudder area ratio. Second type are complex numerical 'efficiency criteria'of steering arrangement deriving from rudder-propeller-hull geometry. Third type are the
criteria of direct regulation of maneuverability elements from full scale tests or computer simulations. Method is now expanding in use, but meets problems in application to small ships with accuracy of measurements and predictions. Criteria of controllability are grouped into turning ability, initial turning ability, course keeping, stopping and positioning. Algorithm for simulations ship's non-stationary dynamics is described and sample of maneuver simulations are provided.The results of turning circle tests are given forvarious small vessels, including multihull craft. Directional stability and turning ability criteria are proposed for small ships.
Paper 17
Rudder Systems
H e n n i n g K u h l m a n n ,
Becker Marine Systems, Germany
K e y w o r d s : r u d d e r s y s t e m s , s u p p o r t , s u p p l y
Our l udders are used for all types of vessel and demanding requirements, from exceptional manoeuvring at slow speeds to cavitation-free rudder profiles at high speeds. Rudder size is unlimited, and severe ice classes, dynamic positioning and high bollard pull with our Kort nozzles are other requirements we can fulfil.
Becker rudders with KSR (King Support Rudder) bearing guarantee best possible manoeuvrability of your vessel with lowest possible fuel consumption. These are the advantages:
Optimum balance and r1ap area ,Minimum additional resistance induced during manoeuvring ,Minimum size of steering gear. Highest securing against flexural vibration. Best values of natural vibration ,Highest safety against cyclic stresses. Maximum security in case of damage. Durable in ice ,Easy maintenance of link system Becker has enhanced the development of twisted leading edge rudders. The result is a rudder that is twisted at different angles into the direction o f t h e propeller swirl, improving the propeller slip stream through the rudder area. The rudder profile has a reduced profile section thickness and suffers no significant pressure peaks that would trigger cavitation. The TLKSR™ design combines twisted leading edge technology with the Becker KING SUPPORT RUDDER (KSR) arrangement and optimises the velocity of the water. Another benefit is the water flow deflection that increases the effectiveness of propulsion and prevents fuel consumption. The HERUS'^ rudder is specially designed for relatively slow and large vessels such as bulkcarriers and tankers. The leading head section integrates the rudder trunk. It comprises hydrodynamic efficiency and bending moment absorption as well as an improved course keeping Leading head replacing conventional rudder horn, No cast parts in leading head. Reduced number of bearings. Efficient absorption of bending moments. Reduces stock diameter and thickness of rudder blade. No alignments of bearings on board. Fast, simple and cost efficient installation. Reduced maintenance Modern shipbuilding means assembly of components and blocks. The HERUS® rudder is a complete component, ready for installation in the yard. Due to our KSR (King Support Rudder) bearing we are able to produce NACA profile full spade rudders unlimited in size. Advantages against conventional semi spade rudders:Only t w o dimensional stress distribution in rudder stock, only one dimensional stress in water bearing, high balance ratio, Avoidance of gap cavitation. Better hydrodynamic characteristics, high manoeuvrability performance, no lower pintle bearing The Schilling rudder is a high lift
rudder, designed for vessels of any size, and supplied in single or multiple configurations. Being of a single piece construction with optimised shape and no moving parts, the Schilling rudder dramatically improves both course keeping and vessel control characteristics.The principal Schilling design configurations are the Schilling MonoVEC (Spade) and the Schilling MARINER (Semi-spade).
Paper 18
Electric Propulsion in Field Support Vessels
Alf Kare A d n a n e s ,
Technology Manager, ABB Mahne, Norway
G u n n a r H i d e ,
Sales Manager OSV Vessels, ABB Mahne, Norway
Key words: OSV, AHTS, electric propulsion
Electric Propulsion is used in a broad range of vessel types and applications, and in the Offshore Support Vessel (OSV) segment, a large portion of new buildings are equipped with a diesel electric power plant, and with variable speed electric motors to control the propulsion and thrusters. Until now, there are still very few Anchor Handling Tug Supply (AHTS) vessels that are build diesel electric, although economical analysis shows that potential gains are even higher than for Platform Supply Vessels (PSV).
The paper presents applications of electric propulsion in the OSV market, its characteristics and benefits for construction and operational costs. Also, the use of electric propulsion in AHTS is discussed, and a comparison on operational economy is being presented, showing the potential savings in fuel consumption and operational costs for three alternative designs:
- A classic design with direct mechanical shaft-line Controllable Pitch Propellers (CPP) - A design with electric propulsion and mechanical, Z-drive azimuthing propulsors - A design with electric. Compact Azipod® Propulsors
The study discuss the main characteristics and criteria for selection of solutions based on a Life Cycle Cost (LCC) assessment.
The paper concludes that for typical operational profiles, OSV and AHTS vessels may have a significant benefit of electncal propulsion. Normally, however not always, the yards will require a higher construction cost for such vessels, compared with classic designs, but the additional costs can be paid back several times during the life time o f t h e vessel. For the charterer and ship owners, this is a very important issue to be aware of since the fuel costs normally are paid by charterer and the building cost by the owner. If ships with electric propulsion that can be proved to give savings in fuel costs, gain a higher day-rate or other compensation for the additional building costs, this would stimulate the industry to select the most o p t i m u m solution, and thereby reducing the overall costs and also environmental impact of offshore operations.
Paper 19
Propulsion of Offshore Support Vessels
Jens Ring N i e l s e n ,
Manager Propulsion R&D, MAN B&W Diesel A/S, Denmark
Rasmus M a n d r u p J e p p e s e n ,
Research Engineer, MAN B&W Diesel A/S, Denmark
Ege L u n d g r e n ,
Research Engineer, MAN B&W Diesel A/S, Denmark
Key words: Custom built and integrated propulsion packages, bollard pull improvement, nozzle design
This paper describes how the design process works at MAN B&W Diesel A/S when delivering propulsion packages. The company's strategy is to be a single source supplier for offshore support vessels. The recent technological progress done in the field is presented in this paper.
An o p t i m u m designed solution for an offshore supply vessel requires a custom built and integrated propulsion plant using mainly standard components. As an example of this, t w o engine configurations for a bollard pull of 100 tons with different nozzles are presented to show the various possibilities and the idea behind the design process. Gaining the last 5-10% bollard pull can be achieved by improvements on the components and/or the interaction between them. A few examples ofthese are hull/propeller interaction, nozzle design, propeller design or efficiency improving devices. At MAN B&W Diesel there recently has been a focus on nozzle design. Numerical tools like CFD have been introduced and studies of various nozzle design parameters have been made. The outcome of this is a new improved nozzle design called AHT that enhances bollard pull.
Making an optimal custom designed propulsion system solution involves many parties such as owners, shipyards, consultants and suppliers. Making the best solution for the customer requires close cooperation between them. Using CFD as optimization tool, MAN B&W Diesel has developed an improved nozzle designed for bollard pull condition.The most interesting results o f t h e latest development supplemented by model test results will be presented.
Paper 20
ACERT® Technology: How Caterpillar Engines Meet Current and
Future Emission Limits
S t e p h e n J Phillips,
Coterpillar Marine Asia Pacific Pte Ltd
K e y w o r d s ; Emissions, R&D, Key Technologies, EIAPP
In 1999, Caterpillar started to fund R&D work for what would become the largest single effort in this industry, with the following objectives:
Meet the most stringent current emission rules Enhance true customer value
Minimize pollutants where they are generated, i.e. in the combustion space
We have also developed a technology, which serves as a stepping-stone for meeting future regulations applying evolutionary steps.
The result is what we call the ACERT® Technology, a unique solution for emission reduction. It has already been successfully introduced for high-speed, heavy duty all the way up to some 1700 hp. What makes the difference? It is the superior system integration of key technologies:
A hydraulically actuated, fully flexible fuel system, capable of split injections, variable timing and able to flex in injection intensity and fuel rate.
A high boost, single- or two-stage, very compact turbocharger arrangement to reduce the combustion temperatures by increasing the amount of air.
Flexible, electronically controlled valve timing combining Turbo Power with Intelligent Valve Control optimizing fuel efficiency and emission for each operation point.
A low emission combustion system with intensive mixing for rapid combustion.
As the flexibility o f t h e system is increased, a huge number of parameters can be now selected to change the characteristics of Fuel Systems and Air Systems. Powerful Caterpillar electronic controls do the job. Finally, simple and reliable oxidation catalysts are used only as an exception to finish the good combustion j o b done by the engine itself
The application of ACERT® Technology across the whole Caterpillar engine base has offered a unique opportunity to strengthen the position o f t h e reciprocating engine, a technology invented more than 100 years ago. Power density has demonstrated quantum steps without affecting reliability. Efficiency is unparalleled. All this happened under the pressure of economics.
Superior system integration, or what we have defined as ACERT® Technology adds a new dimension. It has resolved the complicated balance between superior customer value and low emissions.
Paper 21
Offshore Supply Vessels equipped with Voith Schneider® Propellers
Ivo B e u ,
Voith Turbo Mahne GmbH & Co KG, Heidenheim/Germany
K e y w o r d s : Offshore, support, supply, VSP, propulsion, seakeeping, efficiency
The vertical axis cycloidal or Voith Schneider® Propeller (VSP) has by no means reached the limits of its development. A new generation of VSP with enhanced hydrodynamics and improved construction is already introduced into the market.
Use o f t h e latest computational fluid dynamic methods (CFD) in combination with model tests allow continuous improvement of hydrodynamic performance. New blade profiles with higher efficiency have been developed and hull designs using the VSP are now the subjects of continuous research and improvement at Voith.
The new propeller generation has higher maximum input power. So the re-design of each component with an industry leading structur analysis (FEM) program is used. This provides the power of linear and non-linear structural analysis capabilities to provide reliable structural simulation results. New construction principals for key components such as blades and main bearings have been developed.The first shipset ofVSPs with 6 blades (instead of 5) and improved hydrodynamic efficiency is already installed and has been successfully tested during trial runs.
Branch mark model scale tests have been performed and showing superior efficiency of VSP over other competitive propulsors.
These competitive model scale test as well as other model testing and developments of Voith Turbo Marine and the first PSV for Rederi 0stensj0 A/S are the topics of this paper.
The comprehensive joint investigation program performed by Ostensjo Rederi A/S and Voith Turbo Marine at Marintek and the SVA Vienna have proven a much better propulsion efficiency of the VSP solution over the entire operation draught range as well as the speed range.
Under consideration o f t h e operation spectrum for an OSV considerable fuel saving is possible. Furthermore the excellent sea keeping behaviour was proven and documented.
Additional to the known and proven advantages of the VSP with respect to: - Redundancy
- Controllability
- Fast and extremely precise thrust control for DP mode - long lifetime and very low downtimes
- Automatically built-in c.p. characteristic with the corresponding flexibility in o p t i m u m adaptation o f t h e entire power train to the different operation modes
The function of roll stabilisation can be offered foran OSV application. These aspects will offer to a modern OSV some absolutely new and outstanding performances.
Paper 22
Electric Propulsion in Ice Going OSVs
A r t o U u s k a l l i o ,
Sales Manager Ice-going and Ice-breaking Vessels, ABB Manne, Finland
A l f Kare A d n a n e s ,
Technology Manager, ABB Mahne, Norway
Key words: OSV, AHTS, ice-going, ice-breaking, electric propulsion, Azipod
An increasing part of world's oil and gas reserves are located in Arctic areas, such as in the Barents Sea and in East Siberia. Year-around operations in these areas put strict requirement to the vessels that are supporting the offshore field, and the use of ice-going and ice-breaking Ofi'shore Support Vessels (OSV) is rapidly increasing.
It is the long experience from ice-breaking vessels in the Baltic Sea and Russia that has created the platform of knowledge that much o f t h e new arctic OSV designs are based on.The design criteria and dimensioning methods have been developed from operational experience and with established tools and methodologies. However, it has shown that testing in arctic model test basins is a key criteria for successful hull design and propulsion rating and designs.
Some important design criteria for the electric power and propulsion system is highlighted, and explained. The Azipod ® propulsor, where the electric motor is located in a submerged podded, 360 deg azimuthing unit, has been dimensioned for strict, arctic ice class conditions, and this system will be presented in the paper.
Hnally, selected solutions for electric propulsion for ice-breaking OSVs are presented, with example installations. The Azipod® propulsor has been used in ice-going and ice-breaking vessels in over a decade and this concept has shown to be reliable and very good characteristics when operated in ice. Due to the short, gear-less shaft transmission from the podded electrical motor to the fixed pitch, ice class dimensioned propeller, it may be designed to take up the extensive load torque variations when operating in ice, compared to a mechanical geared power transmission, with long intermediate shafts. Maneuvering, DP capability, redundancy, and reliability is superb compared to conventional mechanical designs, and electric propulsion provides the flexibility that is needed for operation through-out the year with a broad operational span.
Paper 23
Electrical Propulsion Systems for Offshore Support Vessels
Mr. Ivar A n d e r s e n ,
Manager Power Systems; Offshore & Mahne ASA, Norway
Developnnent and design of offshore support vessels (OSVs) have during the last years nnore and more focused on operation availability, redundancy, cost-effective and safe operation, as well as improved performance for its intended purpose, than make a work-horse, only.Thanks to the power electrical industry making innovative solution possible.
During the lecture I will start with the different types of OSVs and their requirement and main capability, and thereafter explain when electrical propulsion systems (EPS) are preferred, and when combined electrical &
mechanical propulsion systems or conventional systems will be the choice. Platform support vessels, anchor handler tug supply vessels, construction vessels, pipe layer vessels and diving support/service vessels will be handled, and focus will be on "a solution for each application", with examples.
Furthermore, the "why, where and how" of diesel electrical propulsion will be handled, in o r d e r t o bring everything in the correct perspective.
Particular requirements for electrical power & propulsion systems, as analysis and calculations, of short circuit level, harmonic distortion, load flow, protection and relay setting, as well as DP classes and their segregation requirements, and integration and the global view from prime movers to propellers will be handled.
Last, but not least, some brief comparisons between electrical and mechanical systems, between FPP and CPP propellers, between pod-propellers and azimuth propellers, between high speed and medium speed prime movers, and between high voltage and low voltage applications, will be lectured.
My lectures intention will more be an overall presentation of "all electric vessels" than detailed presentation of particular equipment a n d / or technological questions. But if the Committee, after receiving the different paper-proposals, like to see a more edged lecture, I can moderate the generality.
Paper 24
New Diesel-Electric Propulsion Concepts for OSVs
D i p l . I n g . J o a c h i m M ü l l e r ,
Sales and Project Manager Offshore and Sea Going Vessels, SCHOTTEL GmbH & Co. KG
Key words: offshore, support, supply, diesel-electric
Diesel-electric Pod drives are well known and have become the standard drive for large cruise liners and ferries. But are these drives reliable and economical enough as propulsion systems for offshore supply ships?
In the power range from 1 to 5 MW, SCHOTTEL has developed t w o new concepts based on simplicity and ingenious ideas, working on the basis that "every part you leave out cannot fail:
Rrstly, a small Pod drive (SEP) fora power range of up to 5 MW using a simple, straightforward asynchronous motor. When the small Pods were developed at SCHOTTEL, the focus was on:
- Simplicity
- Easy maintenance and the possibility of carrying out repairs worldwide - Comparability with all available "off-the-shelf" electrical diive systems - Cost-effectiveness
Secondly, a combination of Pod and mechanical azimuthing thruster, the so-called Combi Drive (SCD). First installations of this Combi Drive will be on double-ended ferries.
The advantages o f t h e Combi Drive are:
- Compact design ("shortened" L-thruster) inside the vessel - Low-cost Pod
- Electric motor combined with the thruster as a single unit - Reduced gear losses (only 3% mechanical losses remaining) - Fewer mechanical parts (dispensing with upper gear) - No alignment of gear, shaft line and electric motor
- Utilization of proven mechanical parts from existing thruster series
Are such drives suitable for OSVs too? What are the pros and cons? This paper provides an overview o f t h e development of both systems, their technical features, current references and future potential applications.
Paper 25
Common Rail Diesel Fuel Injection Technology
Concept ond System Application
Klaus D e l e r o i
General Manager - Sales & Application Engineering, MTU Asia
The MARPOL convention concluded by the International Maritime Organisation sets out the rules for the reduction of pollution by international shipping. One ofthese rules concerns NOx emission by marine engines and applies to diesel engines with a capacity of over 130kWon board vessels for which keel is laid after 1 Jan 2000 and which do no operate exclusively in national waters.
Reducing NOx emission without fuel consumption penalty typically requires improvements of compression ratio, air supply system, injection system and combustion chamber design. Conventional systems have constrains to optimise the combustion process as injector pressure and the characteristics of the injection cycle are determined by the shape o f t h e cam shaft and geometry o f t h e injection pump and thus remains unalterably fixed over the whole of engine's operating range.
This paper describes the consideration of an optimal combustion process, the characteristics o f t h e c o m m o n rail fuel injection technology and comparison with the conventional ones and how it helped achieve the requirements laid down by MARPOL.
Turbulent Kinetic Energy Mean Flow Velocity
Conventional Combustion Chamber
Combustion Chamber with Common Rail
Common Rail has facilitated the use of an optimized combustion chamber that allows the engine to meet emission standards, improve operation flexibility and substantial reduction of visible smoke. By using c o m m o n rail injection system the injection is now independent of engine speed and the injection process is independent of cam shape. The principle of c o m m o n rail fuel injection is based on a high-pressure accumulator system fed by one or more special high-pressure pumps. It provides the electronically controlled Injectors with a constant supply of fuel throughout the injection period regardless of engine speed. This arrangement allows independent control of all
