5.1 The guidance values
are based on ISO 6954:1984 Mechanical Vibration and shock -Guidelines
for the overall evaluation of vibration in Merchant Ships (1984).
The limits of this Standard have been adopted as
Figure 6.5.1 Accommodation and workplace vibration levels
of the Guidance Notes.
The amendments and interpretation are intended to facilitate:
simpler analysis of routine survey measurements; evaluation of the
sum of two or more frequency components; and differentiate between
rest and working areas.
5.2 The severity criteria
are intended to apply to the position of maximum vibration within
the space under consideration. Vibrations in each of the three orthogonal
directions should be assessed independently. Analysis of measurements
should be in accordance with
Ch 3, 2 Analysis for ISO 6954:1984
.
5.3
Broadband
measurements
The following severity classification applies to broadband measurements
of the maximum overall vibration amplitude (peak) for vibrations within
the frequency range 1 to 100 Hz. The values are the maximum repetitive
amplitudes which occur during a minimum measuring period of 60 seconds.
Vibration levels are normal if:
- Velocity is below ± 6 mm/s peak,
or
- Acceleration is below ± 0.15 m/s2 peak.
Vibration levels are excessive if:
- Velocity exceeds ± 15 mm/s peak,
and
- Acceleration exceeds ± 0.30 m/s2 peak.
For intermediate vibration levels severity should be assessed
from a narrowband frequency analysis as described in
Ch 6, 5 Lloyd’s Register’s assessment of accommodation and workspaces based on ISO 6954:1984 5.3
.