6.1.1 All fabrication tolerances are to be in accordance with good
shipbuilding practice and be agreed with LR before fabrication is commenced. Where
appropriate, tolerances are to comply with a National Standard. In general, the
tolerances for the fabrication of structural members for fatigue sensitive areas are
to comply with the requirements of this Section.
6.1.2 For cylindrical members, the out of roundness is not to exceed 0,5 per
cent of the true mean radius. Applicability of absolute out of roundness tolerances
to structures with large diameter to wall thickness ratios (D/t>300) will be
specially considered e.g. circumturret bulkhead.
6.1.3 When measuring cylindrical members, the out of roundness is to be
measured always as a deviation from the true mean radius in order to avoid
errors.
6.1.4 Cylindrical members are not to deviate from straightness by 3 mm or
l mm, whichever is the greater, where l is the length of the
member, in metres.
6.1.5 The misalignment of plate edges in butt welds is not to exceed the
lesser of the following values:
- Special structure 0,1t or 3 mm
- Primary structure 0,15t or 3 mm
- Secondary structure 0,2t or 4 mm
where
|
t |
= |
thickness of the thinnest plate, in mm. |
See
Figure 8.6.1 Misalignment of plate edges in
butt welds.
Figure 8.6.1 Misalignment of plate edges in
butt welds
6.1.6 Misalignment of non-continuous plates such as cruciform joints is not to
exceed the lesser of the following values:
- Special structure 0,2t or 4 mm
- Primary structure 0,3t or 4 mm
- Secondary structure 0,5t or 5 mm
where
|
t |
= |
thickness of the thinnest plate, in mm. |
See
Figure 8.6.2 Misalignment of non-continuous
plates.
Figure 8.6.2 Misalignment of non-continuous
plates
where
|
s |
= |
stiffener spacing or unsupported panel width, in mm |
|
t |
= |
plate thickness, in mm. |
See
Figure 8.6.3 Plate deformation.
Figure 8.6.3 Plate deformation