In recent years, it has become standard practice to regulate
vibration aspects for a newbuilding on a contractual basis. In the
newbuilding contract, limit values that must not be exceeded during
operation of the ship are defined as being part of the specification.
The shipyard thus bears the responsibility for ensuring that limits
agreed on with the shipping company are not exceeded or – if they
are – for taking action with the aim of reducing the vibration level to
the permissible value.
At the preliminary design stage or during the structural design phase,
the shipyard will carry out adequate analyses or will have them
performed by an independent consultant. Amongst other things,
the scope of theoretical investigations regarded as neces-sary in
a given case depends on the agreed limit values, the type of ship,
the propulsion plant, and so on.
There are essentially three areas which are often included in the
building specification to define vibration limits:
• Effect of vibrations on human beings
• Structural vibrations
• Vibrations of engines and equipment items
In the following, a few important standards that are often used to