Tetra Tech INCA reviewed the existing crane’s data and drawings and prepared an inspection plan including applicable checklists. Site inspection of this 1950s crane included the structures, hoists, gantry and trolley drives, motors and controls, operator’s cab, onboard diesel generator power source and fuel supply, lifting beam, crane rail wear and damage, wire ropes, brakes, painting requirements, and power and lighting circuits. INCA performed sampling and testing of materials for asbestos and lead.

A report containing the results of the field inspection, condition assessment, and alternative refurbishment plans with recommendations and cost estimates was submitted to the client. All electrical systems were slated to be replaced, including the onboard 100kw diesel generator and power distribution. Variable frequency drives replaced the existing magnetic controllers, and all mechanical systems were refurbished.

The existing fendering system at the Port of Tacoma’s Terminal 4 was not adequate to handle the size and class of ship currently operating there. Consequently, the Port hired Tetra Tech INCA to study potential fender alternatives that would provide outstanding pier fender protection without interrupting service.

The selected fender pile system consists of modules spaced 80-feet on center. Each fender module has two steel pipe piles driven vertically to position and support a prefabricated fender panel. This fender panel has two steel pipe sleeves which slide over the fender piles and two additional steel pipes oriented vertically.

Tetra Tech INCA provided engineering and survey services for design and prepared contract drawings and specifications for a new concrete apron at Terminal 30 for the Port of Seattle. The project included installation of 400 linear feet of new concrete aprons, demolition of the existing apron, design of a new concrete apron, and design of an electrical substation and rails for a new 100-kip operating load crane. INCA prepared a 15% cost estimate and updated it throughout the design to assure the owner that the budget would be met.

This $6 million apron contract included pretensioned concrete deck panels placed over water, a five-foot-diameter drilled shaft system to resist lateral earthquake loads, underwater dredging of contaminated and clean soils, underwater pile driving and riprap placement, ship and barge moorage load design, concrete pretensioned piles driven under water, underwater surveying, and sonar mapping.

Pier 23 is located on the southeastern shore of Commencement Bay. Originally built around 1946, the pier serves to support the equipment, personnel, and operations of the 70th Regional Readiness command of the US Army Reserves. A concrete extension was added to the pier a few years later, making the pier approximately 1,216-feet long by 56-feet wide. The landward 606 feet of the pier consisted of timber construction and the outboard 610 feet of the pier consisted of concrete construction. Tetra Tech INCA provided engineering during construction services and developed 23 construction drawings, 13 project specific specification sections, and a detailed MCACES construction cost estimate.

The existing timber portion of the pier was demolished and replaced with a new concrete pier for this project. The replacement pier was constructed of precast/prestressed concrete piles supporting cast-in-place (CIP) pile caps and precast deck panels. The new pier is approximately 600 feet long and lies between the existing concrete pier and the existing sheet pile bulkhead wall, which extends along the shore bank. The pier foundation system supports the vertical loads and lateral loads through a foundation system consisting of pile caps supported by vertical and battered piles, which transfer the load to the soil in friction and end bearing.

Tetra Tech INCA performed design computations, finite element stress analyses, and detail design for Swift No. 2 surge arresting pipeline and structures.

The effort comprised:

• One 15’10” square to round intake transition
• Two 15’10” diameter bends
• One 15’10” diameter pipeline (penstock) on a 19 degree slope
• One 15’10” x 11’4” bifurcation
• Two 11’4” diameter pipelines each with a bend and a 11’4” x 6’0” reducer

The design and analyses included the design of all site handling, supports and erection devices, internal temporary stulling rings to resist concrete embedment loads, as well as hold down ties / supports for concreting.