Steering gear box testing – How do you check for correct functioning of marine steering gears?


The engine room of the ship is literally a huge factory with hundreds of big and small machineries and devices. Although the ship control room of modern ships, has the facility to check all important parameters from the comfort of a single place, still it is important to carry out actual checks of various important machineries before starting out for a voyage.

The steering gear arrangement of the ship is certainly one of the most important equipment since along with the propeller, it helps to manoeuvre a ship in the right direction. You certainly dont want to be in the middle of the sea without any control over which direction you are heading at, and totally at the mercy of the feiry elements of nature. Hence it is important that a sort of black box testing is done of the steering gear

A steering gear failure might lead to collision, grounding or some other adverse condition. Thus for a satisfactory operation, steering gear should be well tested before a ship’s departure from any port. Infact it is a mandatory routine and one of the most important items of the engine room departure checklist. Any failure to comply with the same could lead to serious consequences.

Steering Gear Testing

Steering gear testing comprises of a series of tests on the whole steering gear system that should be carried out religiously. The tests include:

  • Testing of the main steering gear operation
  • Testing of the auxiliary steering gear system
  • Testing of the main and standby pump
  • Testing of the tele-motor system, remotely operated from both bridge and engine control room.
  • Testing steering gear operation with emergency power supply.
  • Testing of rudder indication system with respect to the true angle of rudder.
  • Testing of remote control alarms and steering gear power units.
  • Testing of automatic isolating arrangements

Additional Points

The operation of the main steering gear, along with all the other equipments related to it should be carried out by a responsible engineer officer. During the tests the rudder should be moved in both the directions with an angle of 35 degree each. The time taken by the rudder to move from one extreme angle to the other should not exceed more than 28 seconds. The level of the hydraulic oil in tank should be continuously monitored and the tank should be filled completely prior to the manoeuvering process.

All the responsible officers should be familiar with the operation and maintenance of the gear. Moreover they should also aware of the change over procedures along with reading the block diagrams of the system. All the tests should be carried out within 12 hours of the ship’s departure. The connecting linkages should also be visually inspected for damage or wear.

There is also an arrangement for emergency steering in case of sudden fault developing in the steering gear system on a ship. Apart from the routine checks and procedures of the main system, the operation of the emergency steering gear should be checked manually from within the compartment once in every three months. I will be posting an article on the emergency steering gear testing very soon


Introduction to marine engineering – D.A Taylor