Risk-Based Inspection Technique - Offshore Structures: Design, Construction and Maintenance - page 583

TABLE 8.12 Splash-Zone Corrosion and Damage

Extent of Corrosion Score

None and light corrosion 0

Moderate corrosion (approx 50% coverage) 3

Heavy corrosion 10

No corrosion data 10 or go to Table 8.13

TABLE 8.13 Corrosion Condition against Topside Loads Where No Data

Exist on Extent of Corrosion

Original Topside Weight
Known Estimated

No weight growth or known/believed weight growth
≤

3 7

10%

Known/believed weight growth > 10% or no data 8 10

members are designed to be buoyant. Basically, damage like a crack or a hole
has allowed water to enter the flooded member. In some cases, the cause of the
flooding cannot be found, and this is the condition considered here. The basic
assumption is that, although the specific damage is unknown, it is still signifi-
cant enough that it will affect member strength, and if enough members are
flooded, it will affect platform strength.
In terms of the scores assigned to the number of flooded members, the logic
previously described for damaged members, when applied to flooded members,
will be different and have little impact on the platform strength. A larger num-
ber of flooded members has a greater impact. As with damaged members, the
number of legs and the type of framing scheme also have an impact on the
score.
The number of flooded members does not include members known to be

“ For damaged members, the damaged member factor overrides

the flooded member likelihood of failure score. Only flooded members that
have an unknown cause of flooding are counted.
Table 8.14 is very similar to the damaged members table. It illustrates a
score between 0 and 10, where a score of 0 corresponds to no flooded members
and hence no increase in the likelihood of failure, and a score of 10 corresponds
to 10 or more flooded members and a significantly increased likelihood of

damaged. ”