RAILWAY AGE, NOVEMBER 2024 ISSUE: The HART Skyline location on an island in the middle of the Pacific Ocean adds to its complexity and challenges.
The Skyline rail project is a $10 billion, 20-mile, 21-station rail megaproject in Hawaii, spearheaded by the Honolulu Area for Rapid Transportation (HART). This elevated rail system will connect East Kapolei in West Oahu to Honolulu’s dense urban core, addressing the city’s significant traffic congestion issues. With limited space to expand roads, the Skyline project offers a sustainable solution. Stantec is providing construction engineering and inspection services for this groundbreaking project, which will feature electric and driverless railcars—a first in the United States.
This project has extensive and long-lasting benefits. It aims to reduce Hawaii’s carbon footprint and dependence on imported oil, alleviate road congestion, stimulate the economy by creating jobs, and provide a safe mode of transportation. The trains, supplied by Hitachi Rail, are powered by electricity via third-rail that carries 750 volts at all times. Stantec supports HART throughout the entire project lifecycle, offering services such as pre-construction support including procurement, constructability review, construction management, resident engineering, project controls, and inspection.
Segment 1 spans 11 miles and features 9 stations. It was constructed by Kiewit, Nan Inc., and Hawaiian Dredging Construction Company and opened in July 2023. Segment 2 is another 5 miles and 4 stations, including the Honolulu International Airport. It’s being constructed by Shimmick/Taylor/Granite Joint Venture (STG JV) and is expected to open in late 2025. The final 3-mile, 6-station segment into downtown was awarded to Tutor Perini with a notice to proceed (NTP) in October 2024 and is anticipated to open in 2031.
While there are numerous transit megaprojects under way in the U.S., the Skyline’s unique location on an island in the middle of the Pacific Ocean adds to its complexity and challenges.
Delivering a Complex Megaproject
Managing construction on a project like Skyline is extremely complex. Supporting delivery on a project of this scale requires robust contract management and submittal review/approval processes.
This involves understanding the tools and mechanisms of the contract, or modifying accordingly, to address issues in the field to maintain the contractors’ productivity, while protecting against cost overruns. Change and risk management, including claims defense, are critical components. Items such as provisional sum allowances for field change notices, short supply payments, hazardous materials management, third-party inspections, dispute resolution, betterments, and spare parts are prime examples.
Documentation is vital to managing a project of this complexity. This includes:
- Project controls for risk management and mitigation, schedule management with look-ahead and what-if scenarios for critical path analyses, and payment verification.
- Quality management, such as quality control procedures, audits, inspection and testing plans, safety plans, work plans, as-builts, and non-conformances.
- Submittals, RFIs, and correspondence.
- Access/availability and property acquisition assistance.
Segmental Precast Yard: A Megaproject Within a Megaproject
To meet the project’s needs, segmental construction methods were employed for the first two segments, which are more economical, better for managing road closures, and generally less disruptive for the size and length of the project.
The segmental precast yard for the Skyline project was a significant undertaking in itself. Spanning 34 acres and employing up to 300 workers for construction of Segment 2, the yard was capable of storing up to 1,000 segments, double-stacked. Quality control was a critical aspect, ensuring that all operations met stringent specifications. The yard handled rebar (including track plinth inserts in the top flange), conduits, stress blocks, transverse tendon installations in the top flange, including post-tensioning (PT) stressing and grouting operations, along with match-casting for each segment, soundwalls, point and patch operations, and typical repair procedures. Once completed and quality personnel signed off, the segments were stored and then hauled out for span erection.
Tracking for Buy America compliance was meticulously managed, ensuring that every piece of material could be traced from its origin to its final location on the project. This included a unique barcode system employed by the contractor stamped onto each segment.
Supply Chain Management on a Pacific Island
Managing the supply chain for a project of this magnitude on a Pacific island presented unique challenges. Time and distance had to be carefully managed for both materials and personnel. Schedule management for material procurement was crucial to ensure that structural steel, rebar, canopies, and specialty equipment were available when needed in the field. Personnel management included coordinating specialty inspections for station construction, following International Building Code (IBC) certifications for structural steel inspections.
Contract clauses, such as those addressing short supply, were essential to mitigate risks and ensure that the contractor could be compensated for material cost increases. The primary source for materials was shipping, with backups at the port for entry. Shipping delays and resource constraints limited supply into the ports, necessitating longer lead times for material procurement. Resource constraints for both material and labor were significant, as relocating personnel quickly was not feasible, requiring meticulous planning and time management.
External Challenges with a Big Project Impact
The project faced numerous external challenges, including natural disasters like wildfires, hurricanes, and tropical storms, which impacted both the island and the supply chain. Tariffs and embargoes also created obstacles, as did the war in Ukraine, which affected material availability and prices. The COVID-19 pandemic severely impacted operations, requiring workers to maintain a six-foot distance, which complicated tasks such as erecting segments, installing rebar, and pouring concrete. Meetings in the field had to be carefully coordinated to ensure that there was effective communication across disciplines. Learning “Microsoft Teams” was the new normal, dramatically improving electronic communication.
However, the pandemic also had some positive impacts. Reduced traffic on roads and at the airport allowed for longer working durations for lane closures and the ability to close more lanes, making maintenance-of-traffic (MOT) closures through the airport more acceptable. From an economic perspective, a large workforce stayed employed through the project, which in turn supported local businesses.
Utility Relocation to Make Way for Construction
Infrastructure on Oahu is aging, dating back to 50 to 75 years ago, with many utilities suspended on overhead poles. Couple this with natural disasters such as wildfires, hurricanes, and tropical storms, this creates an environment susceptible for power and communication outages when strong winds occur—impacting many communities in the area.
Utility relocation was a significant aspect of the project, with a total of 90,000 linear feet of utility lines needing to be moved—a majority were relocated underground providing a safer, more reliable, system. Notifications for de-energizing the 138 kV power lines were needed one year in advance. Managing these relocations with minimal disruption required careful scheduling for planning outages and reconnections, whether during the day, night, weekends, or special times as needed for each business/residence.
Separate contracts totaling $1 billion were established to get ahead of the guideway work. Utility relocations included electrical lines (12 kV, 46 kV, and 138 kV), communication lines (AT&T, Oceanic Time Warner Cable and Hawaiian Telecom, to name a few), and gas and water lines.
Geological Challenges in Hawaii
Hawaii’s unique geology presented additional challenges. Unlike the U.S. mainland’s more predictable silt, sand, clay, and rock, native Hawaiian soils consist of alluvium, tuff, and coralline detritus. The drilling contractor for Segment 2, Legacy Foundations, had to drill the deepest shaft on record, 357 feet deep, to address volcanic rock, ignoring the top 150 feet due to poor soil conditions. This required two weeks of continuous drilling, soil excavation, and hole protection—a truly remarkable accomplishment by the contractor with no anomalies in the crosshole sonic log (CSL) testing or non-conformance reports (NCRs) during installation.
Construction at sea level, including trenching for utility relocations, typically required dewatering and water management. Single drilled shafts, ranging from 7 to 11 feet in diameter and up to 357 feet deep, supported the guideway. A total of 225 drilled shafts were constructed using varying methodologies, including temporary and leave-in-place casing, open hole with and without water, and telescoping oscillators.
The typical sequence of drilled shaft construction involved setting up necessary MOT, best management practices (BMPs), environmental and public protection measures, constructing drill working platforms, mobilizing and positioning drill equipment, oscillating or rotating drill casing into the ground, and excavating soil using spherical/hammer grabs, augers, and cleanout buckets. The material extracted from each drilled shaft was evaluated by qualified personnel to ensure it matched the boring log, and once dry, it was moved to a storage yard or hauled off site.
Contaminated materials were managed according to the project environmental compliance plan. Water was added to the shaft when groundwater was encountered to stabilize foundation walls. After reaching the tip elevation, the shaft bottom was cleaned out, rebar cages were set, and the approved concrete mix was placed while removing any temporary casing. Nondestructive testing, CSL, verified the integrity of the shafts as the top of the shaft was prepared for column construction.
Team Focus
A team approach, referred to as “One HART Ohana,” has been critical to the success of this project. This approach involves everyone on the team (owner, consultant and contractor) removing their individual company hard hat and collectively putting on the HART hard hat and working together to achieve the same project goals. Our approach made it a priority to get ahead of issues, proactively progressing the project by focusing on maintaining the contractors’ productivity, and empowering team members to make decisions.
An example of effective teamwork was the collaboration with an unidentified AT&T Government fiber optic cable that was impacting the critical path. Instead of being hands-off and asking the contractor to figure out a solution, our team provided two possible courses of action as a workaround. This enabled the contractor to continue working on the critical path while the permanent design and construction relocation for the fiber-optic line was provided afterward.
Interface Management – Station Construction
The interface process during design and construction involved establishing Interface Points (IPs) with all HART contractors. The fixed facility contractor responsible for construction of the guideway and stations is accountable for installing the infrastructure conduits, supports, power and grounding for communication devices such as speakers, cameras, and telephones. It is also responsible for conduit installation for Fire Detection Alarm System (FDAS), Supervisory Control and Data Acquisition (SCADA), signage and Video Message Sign (VMS) boards, Ticketing Vending Machines (TVMs) and entrance gates, as well as elevators and escalators. For successful project integration, constant coordination with HART contractors such as the Core Systems Contractor (Hitachi), Elevator & Escalator Contractor (Schindler Elevator Corporation), Fare Systems Contractor (Init), as well as individual artists for each station was a team priority.
An IP is an element of design or construction requiring the exchange of information to ensure the integrated performance of the overall system or other facilities. Exchanges of interface data within the Project Management Information System (PMIS) allowed interfacing contractors to formally request or provide data and information necessary for their work scope. A finalized document contained lists of the agreed interface coordination points and associated documents, memorializing the communication, coordination, and closure of Interface Points by Interfacing Partners for every design package. This documented decisions and agreements, particularly useful for the duration of the project when this information needed to be communicated to differing labor crews.
Stakeholder Management
The success of the Skyline project hinges on effective team focus and stakeholder management. With dozens of stakeholders, jurisdictions, and organizations directly involved, Stantec leads consultation and coordination with more than 40 key agencies and private third-party organizations. Public involvement and community meetings have been a key feature of the ongoing project, including the “Shop & Dine on the Line” initiative, which promotes supporting local businesses through the disruptive construction phase.
Coordination with the City & County of Honolulu (CCH), Hawaii Department of Transportation (HDOT)-Highways, HDOT-Airports, Hawaii Department of Health (HDOH), Army Corps of Engineers, and other authorities having jurisdiction ensured regulatory compliance and effective communication with relevant authorities.
Projects near or on the corridor, such as a pumping station, low-income housing village construction (Kahauiki Village), radio tower relocation, CCH Infrastructure Improvement Projects, and the Airport Rental Car Facility, required careful coordination.
Environmental Compliance in Paradise
Hawaii is one of the most ecologically and environmentally sensitive places in the United States.
Environmental compliance is crucial due to its fragile ecosystems and the cultural significance of its natural resources. For any large-scale project, obtaining the necessary permits and adhering to regulatory requirements is essential to avoid delays and ensure the project’s success. Key permits and regulatory frameworks include:
- National Pollutant Discharge Elimination System (NPDES): This permit is vital for managing stormwater discharges and ensuring that construction activities do not pollute water bodies.
- Programmatic Environmental Hazard Evaluation and Environmental Hazard Management Plan (EHE-EHMP): These plans are essential for assessing and managing environmental hazards across the project site.
- Site-Specific EHE-EHMP: Tailored to address unique environmental concerns at specific locations within the project area.
- Permits for Laydown Areas: Required for temporary storage and staging areas used during construction.
Compliance with the Programmatic Agreement (PA) and Environmental Impact Statement (EIS) is fundamental to maintaining commitments to the community and other stakeholders. These commitments are integrated into the project to ensure that environmental and community commitments and feedback are reflected in the project’s design; then verified during the construction phases. Historic preservation is a key part of the project as well. There are archaeologists on site, State and County agencies, Native Hawaiian Organizations (NHOs) and community groups are regularly consulted.
One of the more challenging aspects of the project for Segment 2 involved construction over four sensitive waterways. To mitigate environmental impacts, several measures were implemented. A No Adverse Impact Study was conducted to ensure that construction activities would not negatively affect the waterways, while flood plain mitigation reports were prepared to address potential flooding risks. Trestle construction was a common approach involving the construction of temporary bridges to support equipment, ensuring minimal disruption to the waterways. Vibration monitoring protected adjacent bridge structures from construction-related vibrations. All these measures, including BMP compliance coupled with weekly inspections and reports, helped minimize environmental impacts.
One major challenge that could have significantly delayed the project was avoided near the airport station, where the discovery of contaminated soil required a site-specific EHE-EHMP. This included soil and water testing for drilled shaft operations to separate clean soil from soil requiring further testing and organizational strategies to track soil piles and ensure proper handling and disposal. Our team was able to initiate a provisional sum, time and materials, change order to provide a funding source to pay the contractor, thereby mitigating a potentially major impact to the project. This was an enormous accomplishment as the fast response significantly reduced the potential impact to the critical path of the project.
Transforming Transportation on Oahu
The ongoing development of a new rail system in Oahu represents a transformative step for transportation in Hawaii. This sleek and modern system is poised to revolutionize how people move around the island. Segment 2, spanning 5 miles with 4 stations including the Honolulu International Airport, is scheduled to open in late 2025. Segment 3, covering 3 miles with 6 stations into Honolulu’s dense urban downtown, is planned to open in 2031.
As it continues to come online, the Skyline will support Honolulu’s robust bus system, creating a comprehensive transit network. Stantec’s transportation planning services, utilizing data-driven approaches, will further enhance the system’s efficiency and effectiveness.
Ultimately, this project is about making a difference for the people of Hawaii, providing them with more transportation options and improving their quality of life. The lessons learned from building Segments 1 and 2 were incorporated into the Segment 3 contract, ensuring continuous improvement and success for the project.
Scott Rostek is Stantec’s Director of Construction Management.
