Section 5 Anchoring, Mooring and Towing - Strong Points

501. Scope

This section specifies requirements for strong points for attaching chains, cables and lines for an- choring, mooring and towing.

502. General requirements

1. A strong point may be used for different purposes. An anchoring or towing strong point may be used for mooring.

2. The minimum number of strong points shall be as follows:

(1) all craft: one anchoring/towing point forward;

(2) craft over 6 m ÄĂ: at least one mooring point aft;

(3) craft over 12 m ÄĂ: at least one additional mooring point both forward and aft;

(4) craft over 18 m ÄĂ: at least one additional mooring point both port and starboard.

503. Strength requirements

1. Introduction

The assessment of the breaking strength shall be made according to 2, 3 or 4.

2. Horizontal load

Each strong point shall be designed and installed, so that it will take a horizontal load, ĀŸ , in kil- onewtons without failure of the strong point or the surrounding structure to which it is attached:

- forward, for anchoring and being towed:

ĀË G XFĖĦĖÄÆ GÈĦĖF

- forward, for mooring:

ĀË G XFĖĦÈÄÆ GĖĦĖF

- aft

ĀĖ G XFĖĦŊÄÆ G ĖĦĒF

where

X = 1.0 (design categories A and B)

= 0.9 (design category C)

= 0.75 (design category D)

ÄÆ is the calculation length:

ÄĂ ĞÄBÄ

ÄÆ G JË

The breaking strength of a strong point for any application need not be higher than that required to withstand a load representing the mass of the craft in the fully loaded ready-for-use condition, ŶÄǼÆ .

Ch 6 Hull Equipment Ch 6

3. Direct calculation

The assessment of the breaking strength of the strong points may be made by direct calculation, taking into account the design category, the configuration of the craft with special regard to the windage area, the hull form, and the wave spectrum in the intended area of operation.

4. Matching strength

Where a

craft manufacturer specifies or supplies lines, chains or cables which exceed the require-

ments of 2 (e.g. where the craft is intended to be used in extreme conditions or lines are required to be easier to handle), the breaking strength of the related strong point shall be not less than 125

% of the rope or chain that is specified or supplied.

504. Detailed requirements

1. Structural support

Craft structures in the vicinity of strong points shall be reinforced to take the loads calculated ac- cording to 503. 2 to 4. Doubling plates or washers of adequate size shall be used where the strong points are secured with nuts and bolts.

2. Corrosion resistance

Strong points shall be made of materials that are resistant to or protected against corrosion.

Where non-metallic (plastics) strong points are provided, the material shall be UV stabilized. In ad- dition, a warning notice shall be listed in the owner's manual to replace strong points showing visi- ble signs of deterioration.

3. Labelling

Where the intended use of a strong point for anchoring and/or being towed is not self evident, strong point shall be labelled.

the

505. Owner's manual

The information specified in ISO 15084 Annex A shall be included in the owner's manual

506. Strength of synthetic fibre ropes See ISO 15084 Annex B.

Ch 7 Steering System Ch 7