Appendix 3: Berth, Mooring and Fendering - TP 743 E

Previous Page  |  Next Page

1  BERTH CONSIDERATIONS

1.1 Alignment of the berth face should be at an angle of less than ten degrees (10° ) to the prevailing current flow as follows:

Current Speed (Knots)	Design Ship’s Deadweight
2 - 4	Up to 100,000 tons
2 ½ - 3	100,000 to 350,000 tons
2 ¼ - 2 ½	Greater than 350,000 tons

 

This requirement may be relaxed to an angle of less than thirty degrees (30° ) for the following flow conditions:

Current Speed (Knots)	Design Ship’s Deadweight
0 - 2	Up to 100,000 tons
0 - 1 ½	100,000 to 350,000 tons
0 - 1	Greater than 350,000 tons

Where the current sets at an angle greater then 30° , the maximum current should not exceed the following:

Current Speed (Knots)	Design Ship’s Deadweight
1	Up to 100,000 tons
¾	Over 100,000 tons

1.2 The minimum depth in the berth area at the state of the tide should not be less than the maximum draught of the design ship plus an underkeel clearance of 10% of such draught. Alternatively, the required clearance may be computed in accordance with the Special Underkeel Clearance Survey (see section 3.6 of the TERMPOL Surveys and Studies) except no allowance is required for the estimated squat calculated for each critical depth. The minimum depth should be provided over at least one design ship length on each side of the centre of the berth.

1.3 All components of the berth and its supporting structures above and below the water should be set well clear of the ships making an angular approach not less than five degrees (5° ) relative to the berth alignment, with contact being made amidships at either end of the outer ends of the breasting faces.

1.4 The distance between the outer corners of the breasting faces should not be less than thirty-five percent (35%) of the overall length of the largest design ship and the distance between the inner corners of the breasting faces should not exceed fifty percent (50%) of the overall length of the smallest design ship which the berth is designed to accommodate (See Diagram A).

2 MOORING GUIDELINES

2.1 The TRC will examine any proposal founded on sound engineering practices. The mooring section below is presented as example only.

2.2 Mooring structures should be located to provide the required longitudinal and lateral restraints, without overstressing, for the full range of ship sizes the berth is designed to accommodate under the most adverse combination of displacement, current flow, wind, wave and ice forces that are within the operating criteria.

2.3 Mooring structures for ships should be located as follows:

• two outer mooring structures for securing the head and sternlines, located so as to maintain a horizontal angle of approximately forty-five degrees (45° ) between the mooring line and the axis of the berth face;
• two interior mooring structures for securing breast lines located approximately abeam of the fairleads maintaining a vertical angle not exceeding forty five degrees (45° ); and
• two inner mooring points (that may be combined with other berth structures) for securing forward and after back springs (See Diagram B).

2.4 The location of the mooring structures should be checked to verify that the mooring restraint requirements of the smallest ship for which the berth is designated are met, taking into consideration of the line strength and the number and location of the fairleads. Leads between ship fairleads and mooring devices should be clear or projections that may snag the mooring lines.

2.5 Mooring structure locations should be verified for satisfactory mooring patterns for the full range of ship sizes in ballast and in full displacement condition and for ships in head-in and head-out berthing positions, unless the berth is designed specifically for a single heading.

2.6 Mooring structures and devices should be designed for the maximum forces generated by the largest ship when in ballast and at full displacement under combined action of maximum current flow and most severe wind and ice conditions from any direction within the operating criteria.

2.7 For berths designed for ships over 100,000 DWT, mooring devices should incorporate quick-release mechanisms. Each hook should be capable of rotating freely in the vertical and horizontal planes through the full range of mooring line angles.

2.8 Every mooring structures and every component of a mooring device should have a minimum safety factor of 1.6. An approved surveyor should be present when each mooring device is factory tested with the maximum mooring load.

2.9 Each hook should be equipped with a locking device to prevent accidental release of the mooring lines.

2.10 Capstans and other electrical equipment used for mooring purposes should be weatherproof and their motors totally encased. If this equipment is located in hazardous areas then it should be approved in accordance with the Canadian Electric Code.

To enlarge image click here

DIAGRAM A: Breasting Arrangements
DIAGRAM B: Mooring Points

3 FENDERING ARRANGEMENT AND DESIGN

3.1 The following Fender System Design criteria is an example of the calculations and factors that a proponent needs to address and are required in the selection of a terminal’s fendering arrangements and design.

See : FENDER SYSTEM DESIGN (PDF)

This document is published on the Transport Canada web site in Portable Document Format (PDF) Adobe Acrobat. This PDF File is 2277KB. In order to view the document, you will need a copy of Adobe Acrobat Reader (version 3.0 or higher). This reader is available free of charge from Adobe’s web site. Please visit the Adobe website where you can download the Acrobat Reader

Previous Page  |  Next Page