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Local Fuel – Shoreham Oil Terminal
Gasoline Ship Import – Layers of Protection Analysis
P & I Design Ltd
DOCUMENT NO: LF364002_RPT
2 Reed Street, Thornaby, UK, TS17 7AF
ISSUE: E DATE: 30.07.15
Tel: + 44 (0)1642 617444
PAGE 27 OF 38
Fax: + 44 (0)1642 616447
www.pidesign.co.ukInitiating Event 2
Cause
Description
Notes
No of
events/year
2
Whilst importing
from a ship
transfer, overfill
of Gasoline Tank
with correct line
up due to the
capacity of the
tank being less
than expected.
Surveyor performs manual dip and
confirms any discrepancy with book-stock
figures are within the accepted tolerance
prior to the start of each import operation.
10 Imports per year. Probability that the
manual dip is incorrect and under-dipped
by a metre or more. (This is the amount
considered between normal fill alert and
overfill where the dip reading could lead to
a problem) = 2.74 x 10
-3
based on HEART
Data. See Appendix 2) (Total Frequency:
10 x .002743 /yr). This is conservative as
here it has assumed the worst case scenario
where the quantity being charged is in
excess of the available ullage.
0.0274
AND I.E. Modifier 1
Cross Check: Operator confirms dip figure
with book-stock figures prior to import.
(Using Software) Book-stock is updated
from receipts (from imports) and exports
(Direct from flowmeters). Probability that
incorrect ullage is not picked up by checks
and corrected = 0.065 based on HEART
Data. Probability based on historical site
date, for operator making cross check error
over 5 years Nil
Conservative probability assumed = 0.1
0.1
Overall Frequency of Initiating Event :
(0.0274) x (1 x 10
-1
)
= 2.74 x 10
-3/
year