Section 5 Rudder and Steering Arrangements

501.

Rudder and steering arrangements

1. The scantlings of rudder post, rudder stock, pintles and steering gear, etc. are to comply with re- quirements in Pt 4, Ch 1 and Pt 5, Ch 7 of the Rules for the Classification of Steel Ships. The maximum service speed of the ship to be used in these calculations shall, however, not be taken as less than stated below:

IA Super 20 knots IA 18 knots

IB 16 knots

IC 14 knots

If the actual maximum service speed of the ship is higher, that speed shall be used.

2. The local scantling of rudders are to be determined assuming that the whole rudder belongs to the ice belt. The rudder plating and frames are to be designed using the ice pressure for the plating and frames in the midbody region.

3. For the Ice classes IA Super and IA, the rudder stock and the upper part of the rudder are to be protected from direct contact with intact ice by either an ice knife that extends below the LIWL or by equivalent means. Special consideration is to be given to the design of the rudder and the ice knife for ships with flap-type rudders.

4. For ships of Ice classes IA Super and IA, the rudders and steering arrangements are to be designed as follows to endure the loads that work on the rudders by the ice when backing into an ice ridge.

(1) Relief valves for hydraulic pressure is to be installed

(2) The components of the steering gear are to rudder stock.

(3) Suitable arrangements such as rudder stoppers

be dimensioned to stand the yield torque of the

are to be installed.