Section 1 Notations
Clasification Society 2024 - Version 9.40
Clasifications Register Guidance Information - Guidance Note for the Classification, Safe Design, Construction and Operation of Tugs, August 2018 - Chapter 2 Classification - Section 1 Notations

Section 1 Notations

Parent topic: Chapter 2 Classification

1.1 Type and Service Restriction Notations

1.1.1 As with all vessels that are to enter into Class, the governing requirements for the tugs are partially dictated by the notations that are to be associated with the vessel.

Notations may describe the type of vessel, its operational profiles, functions and fit out. From a Classification perspective, this guidance note focuses on the Type Notations and the Service Restriction Notations for tugs. Full listings of these can be found in Pt 1, Ch 2, 2.1 Definitions 2.1.6 and Pt 1, Ch 2, 2.1 Definitions 2.1.11 of the Rules and Regulations for the Classification of Ships, July 2022 respectively.

1.1.2 Lloyd’s Register offers a number of different Type Notations for tugs which may follow the typical arrangements listed previously, these are:
  • Tug
  • AHTS (Anchor Handler Tug Supply)
  • Offshore tug
  • Escort tug
For Classification, a vessel assigned any of the above Type Notations should comply with the requirements listed in Pt 4, Ch 3 Tugs and Pt 3, Ch 8, 5.5 Special requirements for tugs and offshore supply ships of the Rules and Regulations for the Classification of Ships, July 2022, the general design and construction requirements of the Rules and Regulations for the Classification of Ships, July 2022, the general Rule requirements for the propulsion and engineering systems of the Rules and Regulations for the Classification of Ships, July 2022 as well as all Statutory/Flag Administration requirements as applicable.
1.1.3 Additional design requirements for Classification are dependent on the Type notation:

1.1.4 Service Restriction Notations indicate that a ship has been classed conditional to operation only in specific areas which have been agreed by the Classification Committee. If a vessel has no Service Restriction Notation, at design appraisal it is considered to be an unrestricted seagoing vessel according to the 100 character notation. In the case of many tugs e.g. Harbour tugs, designing to unrestricted seagoing service may be too onerous, therefore a ‘Service Restriction Notation’ can be used to reflect a more appropriate operational profile of the vessel.

Typical Service Restriction Notations for tugs might be one of the following:

Type of Service Restriction Notations Typical Text for Service Restriction Notations Tug specific explanation
Protected waters service Protected waters service at “geographical location” For vessels limited to conducting operations in nonexposed waters, where the environmental impact on the service is negligible. In general, sheltered water may be considered as waters adjacent to sand banks, reefs, breakwaters or other coastal features, and in sheltered water between islands.
Specified route service For service at the Port of “name of port” For vessels operating within a specific port and within the defined navigational boundaries of that port.
Specified Coastal Service “Country- Specific” Coastal Service For vessels operating within specified maritime coastal waters in accordance with the requirements of the relevant National Administration and/or at a defined distance offshore where it may seek refuge within two hours of sailing at normal service speed.
Specified operating area service For service within “X”nm “name of geographical point” For vessels operating within a specified area.
  Or  
  For service within “defined geographical area”  

Note that this is not an exhaustive list of Service restriction notations and others may be available or agreed by the classification committee. Further information on Service Restriction Notations can be found in Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.1, Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.4 and, Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.6 to Pt 1, Ch 2, 2.3 Class notations (hull) 2.3.10 of the Rules and Regulations for the Classification of Ships, July 2022.

This guidance note makes use of ‘Protected waters service’ Service restriction notation and restriction notations which limit the operational range to refuge of the vessel to within 5 nm or 4 hours at standard operational speed. For example ‘For service within 5 nm of Shoreham Port’ or ‘For service within 48 nm of Eemshaven’ (the second notation represents 4 hours traveling at operational speed of 12 kts)

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