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
The partial jackets and stiff-leg frames will be prefabricated in a shop environment and shipped to site via
barge. The erection of the partial jackets can begin once the individual piles for the berthing structure
have been installed. The partial jacket frames can be lifted and erected onto the tops of the piles via a
barge crane. Although various connection configurations are possible, the partial jackets will likely be
attached to the vertical piles via field welding. Any ancillary bracing can also be installed via field
welding. After the partial jackets are erected and the onshore abutments are constructed, the stiff-leg
frames can be lifted into position and connected accordingly. With the stiff-legs installed, the deck and
trestle framing can be assembled on a barge and lifted as complete or partial assemblies onto the jackets
and stiff-legs via a barge crane. These components are then field welded to the jacket frames and stiff-leg
frames to complete the erection of the primary structural members.
The final selection of the preferred structural option will be made at the detailed design phase of the
project. However, it is anticipated that the buttressed (stiff-leg) option will be selected as it requires
significantly less rock blasting and associated disturbance of the marine habitat compared to the jacket
structure option. It also minimizes the potential design and construction issues associated with the quality
of the rock.
2.3.4 Mooring Structures
Because of the proximity of the shoreline to the tanker berths, the mooring structures will be located on
land. The mooring structures will comprise a rock anchored concrete abutment. During the detailed
design phase, an optimization process will be conducted to determine the most cost effective and practical
locations for the mooring structures.
The abutments will be cast-in-place mass concrete formed and poured directly on bedrock. Some minor
rock surface preparation may be required including cleaning away any loose or deleterious material. The
transfer of load from the abutment to the bedrock will be achieved with rock anchors that are drilled and
grouted into the bedrock. Mooring equipment anchor bolts, electrical conduits, etc., will be cast
monolithically with the abutment.
2.3.5 Access Structures
Vehicular and pedestrian access to the central platforms will be provided by access trestles that lead from
shore to the berth structures. Depending on the final berth configuration selected, the access trestles may
span directly from the main berth structures to shore or they may have intermediate supports of their own.
The onshore supports will consist of cast-in-place concrete abutments that are rock anchored into the
bedrock. Intermediate support bents, if used, will consist of individual vertical steel pipe piles with castin-place
concrete pile caps. To provide spill containment, a cast-in-place concrete slab and curb is
required as the roadway surface. Either concrete box-girders or steel beams can be used as the framing
members that support the concrete deck slab. The two options are described below.
Page 2-14 FINAL - Rev. 0 January 20, 2010