Rule 10 TSS: Traffic Separation Schemes (eBook)

Published Date

November 2013

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Rule 10 TSS: Traffic Separation Schemes (eBook)

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This publication is a guide to navigating and collision avoidance when sailing through a traffic separation scheme. It is useful to all deck officers learning the application of Rule 10 of the COLREGs. Accident case studies illustrate both operational and safety considerations and are visually supported by ARPA screenshots.

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This publication offers comprehensive guidance on using COLREGs when navigating in a traffic separation scheme. The concept of a TSS is explained, in addition to its criteria and design according to IMO guidelines. The book is supported by additional concepts, such as 'hampered vessels', grounding these in COLREGs guidance and offering manoeuvring advice. The aim of this book is to isolate major causal factors that, when followed, break the 'error chain' and stop accidents from occurring.

Section 1         Understanding Rule 10 and the Need for TSS Routeing Measures
                        1.1       A History of Ship Routeing and the Development of Traffic Separation                                Schemes
                        1.2       The Concept and Application of Traffic Separation
                        1.3       Rule 10 Traffic Separation Schemes

Section 2         The Use of COLREGs when Operating in the Vicinity of a TSS
                        2.1       Approaching and Entering a TSS
                        2.2       Lookout
                        2.3       Case Study of the Grounding of ‘LT Cortesia’ on the Varne Bank
                        2.4       Assessing Risk of a Collision
                        2.5       Case Study of the Close Quarters Situation between the ‘Costa                                           Atlantica’ and the ‘Grand Neptune’
                        2.6       Safe Speed
                        2.7       Case Study – Collision Between HSC ‘The Venetian’ and Fishing Vessel                               ‘Yue Tai Shan 33040’ (Safe Speed) 69
                        2.8       Action by Give Way Vessel
                        2.9       Crossing Vessel Encounters within TSS
                        2.10     Case Study ‘Scot Isles’ and ‘Wadi Halfa’
                        2.11     Action by Stand-on Vessel
                        2.12     Case Study of the Collision between ‘Sand Heron’ and ‘Fv Celtit’                                         (Action by Stand-on Vessel)
                        2.13     Overtaking in Clear Visibility
                        2.14     Restricted Visibility
                        2.15     Case Study ‘Tricolor’/‘Kariba’/‘Clary’
                        2.16     Case Study ‘British Trent’ and ‘Western Winner’

Section 3         Special Circumstances to Consider when Transiting a TSS
3.1       Defensive Navigation
                        3.2       Hampered Vessels in a Crossing Situation
                        3.3       High Speed Craft (HSC)
                        3.4       A Special Case – Three Green Lights in Singapore Strait
                        3.5       Pilot Boarding Stations

Following the successful introduction, in 1967, of the Dover Strait Traffic Separation Scheme (TSS), initially on a voluntary basis and later as a mandatory scheme following adoption by the IMO in 1971, there was a dramatic decrease in the number of collisions and near misses in that area.

Since introducing these measures there have been enormous changes to the type of ships transiting the scheme. Ships have expanded in size and container ships of more than 10,000 TEU, operating at speeds greater than 25 knots and with draughts in excess of 14 metres, are now common. The dynamics and geometry of collision avoidance have changed as these ‘gigantic ships’ are generating ever larger interaction forces.

In 2009, the United Kingdom and French governments jointly funded an investigative study aimed at 'Reducing Risk in the English Channel'. An independent team of consultants attempted to identify all the associated causes and problems that were contributing to the perceived increase in safety risks.

This study was carried out using the IMO’s preferred methodology of ‘formal safety assessment’, the aim being to identify risk mitigation measures that could be considered for the ‘risk control options’ produced by the report.

During the many discussions it was felt that most, if not all, of the accidents, incidents or near misses occurred due to:

  • • A lack of knowledge, understanding, or respect for the Collision Regulations
  • • a lack of experience
  • • errors of judgement
  • • failure to appreciate the limitations of navigational equipment
  • • language or communication difficulties
  • • fatigue.

If the International Regulations for Preventing Collisions (COLREGs) are adhered to by ships at all times, collisions should be avoidable.

In my own working life as a deep sea pilot in North West Europe, I have continually observed ships blatantly contravening the COLREGs within the various TSS regions, often encouraging other ships to do the same. While there are many reasons for this, it appears that there is an educational gap, exaggerated by the reduced sea time requirements for officers and the subsequent reduced experience that watchkeeping officers are required to have.

Unfortunately, the demand for a ‘thorough and working’ understanding of the COLREGs appears to have been diluted. In reaction, it is not unusual to see posters of light and signal recognition displayed on bridge bulkheads.

Intervention from shore VTS operators has occasionally added to the problems that ships experience.

It is generally accepted that the vast majority of accidents or near misses are not the result of one factor, but are due to an error chain developing. If the correct risk assessments are carried out and sensible risk control options are identified, the error chain should be broken. The aim of this book is to try to isolate major individual causal factors that, when followed, would have broken the error chain and stopped the incident occurring.


Witherbys titles are developed using scripts developed by technical experts that are peer reviewed within work groups. Typically, they seek to improve understanding of the regulations, recommendations and guidelines issued by Industry.

Witherbys staff have significant expertise in the fields of navigation and hazardous cargoes as well as in the presentation of complex subjects in a graphic and easy to understand manner.

Captain Kevin Vallance

Captain Kevin Vallance has held the role of Master with South Coast Shipping Co and in 2006, became a Trinity House Licensed Deep Sea Pilot. He was elected to the United Kingdom Maritime Pilots’ Association Technical and Training Committee and represented them at a variety of safety meetings during his 5 year tenure. In 2020, he was awarded the Merchant Navy Medal for his services to maritime safety.

Title: Rule 10 TSS: Traffic Separation Schemes (eBook)
Number of Pages: 186
Product Code: WS1405EA
ISBN: ISBN 13: 978-1-85609-606-5 (9781856096065), ISBN 10: 1-85609-606-8 (1856096068)
Published Date: November 2013

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