Section 3.10: Site Plans and Technical Data - Rick Neufeld Comments

Northern Gateway Pipelines Inc.
Section 3.10: Site Plans and Technical Data
Table of Contents
2.2.3.3 Fill for Levelling Courses
Although efforts will be made to minimize the amount of rock overbreak, the surface of the rock face
after blasting will likely be somewhat irregular, which is not ideal as a bearing area for structure
foundations. In order to seat the marine structures properly, it may be necessary to place a layer of
engineered fill or tremie concrete on the horizontal rock faces to act as a levelling course in order to
provide a flat working surface. This surface will facilitate seating of the structures and the drilling of
anchor piles or rock sockets.
2.3 Tanker Berth Marine Structures
Several structure types and construction methodologies were considered during the development of the
tanker berth marine structures. For each concept various criteria were evaluated such as design
practicality, reliability, durability, constructability, and long-term maintenance issues (Reference 2).
Based on a review of the advantages and disadvantages, and the associated risks for each concept, two
options are proposed for each functional element of the tanker berths. The proposed options represent a
range of structure-types and construction methodologies that are considered the most viable for this
project.
2.3.1 Tanker Berth Structural Arrangement
Each tanker berth is comprised of the following functional elements:
• Central Loading / Unloading platform structure;
• Breasting / berthing dolphin structures;
• Mooring structures; and,
• Access structures consisting of main and secondary trestles, and catwalks.
The basic layout of the berths is based on conventional industry practice for tanker berths and complies
with the recommendations of the Oil Companies International Marine Forum (OCIMF), which is one of
the most widely recognized international standards. OCIMF guidelines for the layout of tanker berths are
summarized in Figure 2-4. The berth layouts also generally comply with TERMPOL Appendix 3, Berth,
Mooring and Fendering guidelines. The TERMPOL guidelines (Diagram B, Appendix 3) differ somewhat
from the OCIMF guidelines in that they recommend providing a head line and stern line at approximately
45 degrees from the axis of the largest ships. Although these lines are less efficient than “pure” breasting
lines or spring lines, they do offer some additional redundancy and safety during storm wind conditions.
The proposed berth layout therefore includes additional mooring points on shore, located to provide head
and stern lines lead angles of approximately 45 degrees (see Drawing No. 002). These additional mooring
points could be used at the ship master’s discretion if desired.
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