C+S August 2023 Vol. 9 Issue 8 (web)

systems in the main terminal; designing cost-effective replacement solutions that minimize the shutdown impact on end-users and passenger experience; and implementing the upgrades to provide a safer, more robust, and more reliable electrical system for this critical public facility. Mortenson places a heavy emphasis on planning to proactively address these challenges. Working together with its electrical contractor, Casne Engineering, Mortenson proposed a three- year pre-construction period to ensure a successful project outcome—including advising the design team on all aspects of the construction; assisting in identifying and obtaining space for new equipment and rooms; implementing circuit tracing to create accurate electrical as-built drawings of the entire main terminal building; and working with tenants and airport management to determine phasing and necessary interactions to facilitate construction. Technology has also been an exceptional tool in the project team's arsenal. For example, to better understand the impacts of its work, the team took three-dimensional (3D) scans of particularly congested areas and created 3D models to create accurate construction documents to minimize impacts on airport tenants and visitors. Because the Main Terminal Low Voltage Upgrade project involves more than 2,100 power shutdowns, Mortenson’s due diligence and integrated communications ensure that no shutdowns come as a surprise to airport operations or passengers throughout the course of the project. Through proactive cooperation from all parties—including the owner—the team performs the work in a carefully sequenced and well-communicated manner. Mortenson also uses target value delivery (TVD), as a management practice throughout all phases of design and construction to deliver projects within a fixed budget, while meeting the operational needs and values of the client. Using TVD, Mortenson was able to break project budgets into smaller buckets to help allocate cost and design to each element – making it easier to analyze where savings opportunities and over-run risks exist. The program also provides the working team with ownership over individual scopes, which creates accountability. By resolving numerous unanticipated issues through these communications Mortenson was able to bring the final contract price down five percent less than the original target (a welcome surprise to the client and a great accomplishment in the current market). Providing a Reliable Source of Back-Up Power: SeaTac’s Alternative Utility Facility Mortenson was also the design-builder for the new Seattle-Tacoma International Airport Alternate Utility Facility (AUF). The facility provides a reliable source of back-up power to run everything from runway lights, communication between ground and air, fuel pumps, and maintaining the arrival and departure schedule. Located on an approximately one-acre site at the Seattle Tacoma International Airport near the Port of Seattle’s South Main

Substation, the AUF project's primary focus was to provide a power source for the entire airport in the event of a catastrophic loss of power from the local utility. Special consideration was given to ensure that the facility could operate if any single device were to fail. The facility was designed to withstand major earthquakes and lightning events. The project team worked diligently with the Port of Seattle to identify economies of scale during the design phase that allowed the team to fully build out this critical facility within budget while also expanding the scope to include ten generators instead of eight. Relocation of an employee parking lot and bus staging facility was also necessary for the construction of the project. By scheduling the relocations during slow periods and diligently communicating the impacts of revised routings, Mortenson informed dislocated users well in advance while mitigating impacts to essential airport personnel. As a result, the successfully completed project—including a control building, a medium voltage (MV) switchgear building, and MV automatic transfer switching building on a separate secure campus connected to SETAC’s South Main Substation by MV underground ducts—can supply 30 megawatts (MWe) of power via ten (10) 3 MWe diesel generators. The AUF is also capable of soft parallel with the upstream power supplier (Puget Sound Energy) in order to transition to and from the normal power provider, as well as provide power during an unexpected loss of normal utility power. Understanding the Inner Workings of a 24-7 Environment to Deliver Reliable, Innovative Solutions Completing critical infrastructure improvements requires a deep understanding of the inner workings of a global, 24/7 environment, and the ability to deliver reliable, innovative solutions in extremely sensitive environments. Just as important is extensive engagement with all stakeholders during the design phase to understand their processes and constraints. The use of next-generation technology, such as 3D modeling, to understand the impact of work on areas that cannot be interrupted and detect inefficiencies and clashes before construction starts is also key to success. At Mortenson, we continue to learn invaluable lessons through our ongoing work at SeaTac (and beyond) and look forward to continuing to make sure the built airport environment has a lasting positive impact—while striving to make projects even better than imagined. STEVE LARSON is a Senior Mechanical, Electrical & Plumbing (MEP) Design Phase Manager at Mortenson Seattle. With more than 40 years of dedicated MEP experience, he is deeply familiar with complex facilities and expansive mechanical, electrical, and building systems required for their efficient opera - tion. As a strong proponent of the value that can be gained through design- build, Steve has been a project team member for several Design-Build Institute of America (DBIA) national award-winning projects. His commitment to pre-planning and extensive communication in maintaining high-quality installations is invaluable to all stakeholders throughout projects. You can reach him by email or phone at 425-895-9000 or steve.larson@mortenson.com .


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