Section 2 Means of Going Astern

201. General

1. Units are to have sufficient power for going astern to secure proper control of the unit in all nor- mal circumstances.

2. The ability of the machinery to reverse the direction of thrust of the propeller in sufficient time and so to bring the unit to rest within a reasonable distance from maximum ahead service speed is to be demonstrated.

202. Tests

1. In the astern trial, an order for full astern is issued while the unit is running ahead at the speed

specified in Pt 3, Ch 1, 120. of operation from ahead run to full

Rules for the Classification of Steel Ships, whereby reversing astern run is to be carried out as fast as possible. In this case,

astern operation is to be continued until the astern speed (rotational speed in rpm) is stabilized for diesel units, or for the period of 15 minutes after the order of astern for steam turbine units, gas turbine units and electric propulsion units respectively, whereby the astern performance and stopping

performance are to be verified and the test results recorded are to be available on board for the use as a guidance for unit manoeuvres.

2. In units having multiple propellers, the unit navigating and maneuvering performance with one or more propellers inoperative is to be verified, as well as the test results recorded are to be made available on board for the use as a guidance for unit manoeuvres.

3. When the units provided with supplementary means for maneuvering or stopping, performance test for such means is to be carried out, and the test results are to be available on board for the use as a guidance for unit manoeuvres.