Resonance frequency was a little higher and the amplitude was about 20 per cent small after installation than measured on test bench. The reason of this difference is considered that the flexible joints used for connection with engine room piping was stiffer than expected to a small extent.
Only small vibration within + 0.1mm was measured in any position of the ship, passages, cabines, galley and wheel house. Noise inside the engine room was measured about 100 dB, but the noise level became lesser as further from the engine room of which walls were covered with noise suppressing cloth. Noise from the main engine could not be heard in the galley or in the wheel house.
