Earlier this month, rail officials led a media tour at three future west side stations, giving a better sense of the transit system that’s taking shape.
The event also offered, for the first time, an up-close view of key construction issues that have dogged those stations and others down the line.
The most notable culprit? Canopy arms.
The seemingly innocuous station features have helped drive up costs by millions of dollars in recent years, causing headaches for designers, contractors and fabricators alike. Those issues still threaten to delay the city’s planned opening of interim west side service by December 2020.
The arms will eventually support fabric masts designed to shelter waiting passengers at the rail line’s 21 stations.
Until the recent tour, the public’s only glimpse of those problems came from occasional PowerPoint presentations by the Honolulu Authority for Rapid Transportation in a Honolulu board room, miles away from the actual stations.
“Nothing replaces going out and taking a look at it,” Frank Kosich, HART’s deputy director for design and construction, told the board in 2018, referring to rail construction in general.
Why are the canopy arms so critical? Various wires and conduits that are part of the rail line’s signaling and communications system are designed to pass through them, over the stations. Hitachi, the company that’s building rail’s driverless cars and systems, can’t install that equipment until the arms are up.
The arms have been installed at a third station next to the University of Hawaii West Oahu, named Keone‘ae. No arms had been installed yet at Halaulani at Leeward Community College.
At the third station on the tour, West Loch, also known as Ho‘ae‘ae, no arms have been installed yet. Some of the conduits lining this walkway of the West Loch station, pictured below,will eventually lead to canopy arms, rail officials said.
A Tribute To Hokulea
The canopies were designed to represent the sails of the Hokulea, the renowned replica of traditional Polynesian voyaging canoes and symbol of Hawaii.
Unfortunately, officials realized later that in heavy winds the canopies — like the sails they emulate — would create heavier loads. That led to various design delays, then a $4 million change order in 2016 to address those delays.
Then, in November 2018, HART Executive Director Andrew Robbins revealed that the station canopies were still causing major challenges, this time due to what he referred to cryptically as “constructibility issues.”
“We have challenges to meet the December 2020 (deadline) but if we don’t continue to address it pretty much on a daily basis, you know, we won’t get there,” Robbins told the board. “I don’t intend to give up on that date, but there are challenges.”
At the time, he had trouble elaborating further on those issues. Robbins called it an ”engineering issue in terms of how suitable the design was for construction.”
The issue made more sense while viewing the arms up close during the recent tour.
The unique canopy designs feature appendages that jut out along the trunk. Nan Inc, the local firm building six of the line’s west side stations, had difficulty building them to the specifications of the design, which was created by AECOM, said Sam Carnaggio, HART’s project director. The two companies clashed over whether this was AECOM’s fault or Nan’s, Carnaggio said.
AECOM’s Honolulu office didn’t return a call for comment. Nan declined to comment.
The problems didn’t end with the questions of how to build them, however.
Workers first discovered “prevalent” cracks in four of the canopy arms’ lower segments, before those segments shipped from the mainland, according to HART. Cracks were also found in a fifth arm that had already been shipped.
Officials believe the cracks may have been caused by “hot-tip” galvanizing of the arm’s 100-grade steel, which are treated with zinc to protect them against corrosion. “Micro-cracking” was subsequently found in more arms, Kosich told the board earlier this month.
HART and the other parties are still investigating the cause.
Different arms made with a more mild, 50-grade steel didn’t have the same cracking problems.
Overall, the problem affected some 30 canopy arms planned for the six western-most stations, according to HART’s presentations to the board.
Last week, board members approved up to $10 million to scrap the existing segments and build entirely new ones with 50-grade steel. They are hoping the move will keep the stations on schedule for the December 2020 opening of the first stretch of the line from the fields east of Kapolei to Aloha Stadium.