January/February 2021 - 82

Preconstruction view of Scorpion Anchorage pier site

powered winch for easier access to the
pier from boats, while considering tide
and swell conditions.
The timber deck of the pier is an
ADA-accessible surface with timber
guardrails. To support the structure, 81
piles were installed that are 24 in and
18 in (61 cm and 45.7 cm) in diameter.
The steel pipe piles were installed
within a 26 in (64 cm) diameter
permanent casing. The installation was
to a depth of 30 ft (9.1 m) and included
the use of pier support piles, berthing
piles and lift platform support piles.
Because the elevation of Scorpion
Anchorage slopes downward to greater
depths offshore, the unsupported pile
lengths above mudline vary, ranging
from 5 ft (1.5 m) at shore side to 40 ft
(12.2 m) above mud-line at the pier's
most offshore point.

Remote Logistics
Santa Cruz Island has a permanent
population of two people, making it a
challenging remote location for a major
infrastructure construction project. The
first logistical challenge was to provide
shelter, food and living essentials for a
rotating crew of 12 to 25 men, working
on a schedule of 4 days on and 4 off. This
meant bringing trailers out to the island
for housing, implementing a galley
kitchen with chefs, and establishing a
power source and septic system.
82 * DEEP FOUNDATIONS * JAN/FEB 2021

A major construction challenge was
transporting a large Soilmec 516 drill
rig, crane, excavators, air compressors,
hydraulic motors, generators, tools and
accessories necessary for the remote
project. Loading all this equipment onto
barges or vehicle-bearing landing
crafts was relatively easy in the Port of
Long Beach. However, offloading it in
the breaking surf of the island was a
different matter. Dive surveys of the
ocean floor were undertaken to
determine the best way to bring in the
barges. Weather and wind conditions,
tide levels and the ocean swell had to be
considered. Offloading often ended up
being a sun-up to sun-down operation.

Site Sensitivities
The careful approach to offloading
equipment was just part of strict
requirements for construction in an
environmentally sensitive national
park. Santa Cruz Island is an oceanic
outpost that also contains sites with
evidence of some of the oldest human
activity in coastal Southern California.
The island is also home to unique,
endemic plants and animals.
Archeological investigations indicate
that the Chumash native people
occupied the island for at least 9,000
years until the early 1800s. The island
Chumash developed a highly complex
society dependent on marine harvest,
Pier crew relaxing at end of day

craft specialization and trade with
mainland groups. An estimated 10 to 12
historic Chumash Native American
villages have been discovered on the
island, including one village, Swaxil,
located near Scorpion Anchorage.
The introduction of non-native
plants and animals in the 19th century
caused significant disturbances to the
island's natural ecosystem. Island
species like native island foxes and bald
eagles were soon on the brink of
extinction, while nonnative feral pigs
and their destructive rooting damaged
many archaeological sites. A decadeslong restoration project by the NPS
helped to bring back many of the
island's unique plant, marine and
animal species as well as preserve the
island's history.
Strict guidelines for the
construction process for the new pier
had to be in place to protect and
preserve the fragile island
environment. In order to protect marine
mammals, a 1,640 ft (500 m) safety zone
was established around the
construction site. The NPS had a fulltime monitor onsite during all pile
installations to look for marine
mammals entering the zone. Drilling
would come to a stop until the animal
left the safety zone. Underwater
surveys were also conducted, not only
to identify beds of eelgrass that provide
January/February 2021

Table of Contents for the Digital Edition of January/February 2021
