Hi can anybody advise me on the vibration standards available for machinery compartments (in marine vessels especially steering gear compatrment).
Thanks.

Typically the steering gear on ships built in the last 40 years or so the steering gear is a complex arrangment of electro-hydraulic machinery. But breaking it down into its individual components will give you a clue as how to monitor. The system usually has two motor driven pumps; one is a spare and a good Chief Engineer will rotate service. When the ships wheel is amidships (no turn being requested) the pump rotates but doesn't pump. When a turn is requested the active pump begins to pump through a six-way valve and delivers oil under pressure to one of two opposed hydraulic cyclinders which provides motion to the rudder.

So, fundamentally you have a motor driven pump, relatively small, so I would apply any motor and pump spec you feel confortable with to the machinery. The system should be checked at mid position (no turn requested) and with the ships wheel fully over in both the starboard and port positions. Do this for both motor pump systems, or schedule the spare unit for this test when it is in service.

Back when I was an engineer on merchant ships and in the Navy all steering gears were tested in port prior to sailing. That would be the obvious time for this type of test work.

John

One more thing...transducer type is critical if you are taking readings at sea. The vessel has a "natural" motion in the water. It typically is of the order of 0.5 Hz. This can drive a transducer nuts, particularly if you chose to integrate. Proximity probes are OK, but not the right transducer for a steering gear. Best is a velocity coil with a 600 to 900 cpm low end roll off frequency and don't integrate. Accelerometers can be used if the low end can be filtered out, say a high pass of 5 Hz.