Rail officials first started learning about problems with undersized wheels on oversized track late last year while testing trains running at 55 mph.

But the problem of too-thin wheels and too-wide track — especially at 12 points where the tracks cross one another — was born long ago, when the idea to create the nation’s first fully driverless rail system was just a concept.

Now officials with the Honolulu Authority for Rapid Transportation are working with Hitachi Rail to find a solution — whether to replace 32 wheels on all 20 trains or have new track crossings manufactured and shipped in. Rail and Hitachi officials met in person in Honolulu on Friday.

“There’s blame on both sides,” said Lori Kahikina, HART’s interim CEO and executive director, who inherited a seemingly never- ending list of problems when she took over in January. “It’s for the betterment of the project that we work as a team to figure out a solution.”

Hitachi did not respond to a request for comment on Friday.

The problem has generated even more scrutiny from the Federal Transit Administration.

“We’re the first in the nation to be autonomous (driverless),” Kahikina said. “That’s why FTA is highly regulated to make sure that we’re meeting all of the safety testing certification, because it’s the first in the nation.”

The mismatched wheels and tracks are merely the latest embarrassment for the city’s troubled rail system. It faces an approximately $3 billion shortfall and is not scheduled for completion for another 10 years, even though it’s just 4 miles shy of reaching its scheduled destination at Ala Moana Center, Hawaii’s largest transit hub.

City Councilwoman Heidi Tsuneyoshi introduced a resolution last week urging the HART board to pause rail construction at Middle Street and called the newest revelations “very concerning.”

“We’ve had inspectors upon inspectors upon inspectors, and for this to fall through the cracks shows more than a failure and disregard and lack of attention,” she told the Honolulu Star-Advertiser.

Tsuneyoshi said she appreciated Kahikina “for providing her voice and clarity” on the wheel problem but asked: “What else are we going to uncover going forward? If they failed to see this, what else are we going to find out and how much is it going to cost us?”

HART board member Kika Bukoski said, “I don’t believe we have all the answers to the questions yet. We just don’t. But one positive takeaway is that the issue was identified during the testing phase and that HART is doing its due diligence to identify and address such issues prior to turning it over to the city.

“As far as who is responsible for what and at what cost, we need to let the process play out and allow HART to have those discussions with Hitachi and collect all the information needed to present a complete and accurate report to the board.”

HART board member Natalie Iwasa, a certified fraud examiner, also said that it’s good Kahikina is being transparent about the latest problems, especially compared to previous HART administrations.

Both she and Bukoski said they were not speaking to the Star-Advertiser on behalf of HART or for the HART board.

“People can’t make good decisions unless they have good information,” Iwasa said. “The history with HART was that the information wasn’t forthcoming in a timely manner.”

She said it’s important that HART and Hitachi fix the wheel problem and ensure the rail system’s safety.

“I don’t think anyone would feel comfortable without knowing that safety issues are being taken care of when they come up,” she said. “If there’s even one bad incident it would drive riders away permanently, or at least some of them. Things like this shouldn’t be kept in the dark.”

Fixing the ‘frogs’

There are other issues at the track crossings, called “frogs.”

But fixing the problem of narrow wheels is the most expensive and time consuming and is generating additional scorn and ridicule for rail planners.

“People are mad at me,” Kahikina said.

Each of 20 trains is expected to comprise four cars, each outfitted with eight wheels, for a total of 32 wheels per train. But only seven trains would initially operate.

Each wheel weighs 290 pounds and measures 28 inches in diameter and 4-3/4 inches wide. One possibility would be to replace them with wheels that are the same diameter but a half-inch wider, weighing approximately 314 pounds each.

The undersized wheels work fine along the straight portions of what is supposed to be a 20-mile, 21-station route from East Kapolei to Ala Moana Center, Kahikina said.

It’s at the 12 frogs where the half-inch gap causes problems, forcing the trains to slow down from 55 mph to 15 or 20 mph, which will not accommodate HART’s plans to have trains arriving at stations every four to five minutes.

“Basically the wheels are smaller than the tracks,” Kahikina said. “The issue really is when we go over the crossovers, the frogs. Straightaway we’re fine. Everywhere else there’s a protective guard rail that holds it in place. So even if there’s a gap, it’s not a big deal. At the frogs, at the crossings, there’s not that protected rail.”

There are eight frogs per crossing, for a total of 96. Currently, it’s hoped that only six of eight frogs will have to be replaced.

Even though they look like elongated X’s, they’re conceptually divided horizontally and are called frogs after one of the weight-bearing structures of a horse’s hoof, said Kahikina. She boards a horse in Waimanalo and shoes its hooves herself.

“One frog is like a V and the other one is an upside down V,” Kahikina said. “When you look at the bottom of a horse’s hoof it’s shaped just like that upside down V and it’s called a frog. That’s how old this term is in the rail industry — all the way back to the heydays.”

The frogs also go by another name, Kahikina said: “The double crossing.”

HART ordered the frogs built on the mainland and shipped in to be installed. Hitachi is responsible for the “wheel-rail interface,” Kahi­kina said. But HART gave Hitachi the option of picking two different wheel sizes and Hitachi chose the smaller one, she said.

“To be fair to Hitachi, when HART put out the contract there were two different wheel sizes that they could choose from,” Kahi­kina said. “So from their perspective they choose the thinner one. We’re not both clear. There’s some blame on both sides.”

Replacing the wheels appears to be the simpler and cheaper fix, but negotiations with Hitachi continue over how to proceed and who will bear the cost.

“We’re checking with manufacturers on replacing the wheels and we think it’s about $2 million (or $3,000 each) to swap out all of the wheels on all 20 trains — total,” Kahikina said. “We found a manufacturer, but those are just estimates.”

There are also concerns that wider wheels will make each train about 800 pounds heavier. But Kahikina is still asking questions about the ramifications of heavier wheels.

“We’re questioning Hitachi on that,” she said. “Why is that an issue? … Hitachi is saying they can’t do the bigger wheels because it’s going to go over weight.”

The more expensive solution — to replace six out of every eight frogs — would cost more than double and take more than a year to have them manufactured on the mainland, shipped to Honolulu and then installed.

“The track is much more expensive,” Kahikina said. “We’re estimating it’s about $50,000 per frog. There’s eight frogs per crossing (and six that would likely have to be replaced). There’s 12 crossings. … So it’s about $5 million just for the material.

“It’s going to be a decision between Hitachi and HART. Do we go the wheel route?”

Switch plate welding

HART officials continue to add up the costs for other frog-related issues, but they do not appear to be as severe or costly.

The simplest, at this point, appears to be repairing divots and cracks in the frogs themselves. So far the problem appears limited to three of the track crossings.

Asked why the damaged frogs were not anticipated, Kahikina said: “You won’t see any imperfections until a load is put on to the track. As you’re running it back and forth, then it starts to chip off. So we sent photos to the manufacturer and they said, ‘This is just superficial, not structural, no integrity issues. All you need to do is sand it down and just put a welding on top.’ So that one is very simple. As we keep watching it, there’s been no growth, there’s been no additional (damage).”

At the same time, HART officials are evaluating thousands of switch plates near the frogs that were poorly welded, causing the protective silicone coating to wear off and inhibiting trains from gliding over them as intended.

“It’s all botched up and you see only splotches of weld,” Kahikina said. “There’s thousands of them along the entire rail route. So we are doing an inventory of how many are in bad condition and we need to go back and fix the weld.”

HART purchased the switch plates and had them installed by contractor Kiewit.

“So it’s not a Kiewit problem, it’s not the installation problem,” Kahikina said. “It’s a manufacturing problem. They’re saying, ‘You didn’t properly maintain that silicone. It’s not our fault.’ But we’re saying, ‘Look at the weld.’”

The cost to fix the switch plates is estimated at $150,000 to repair the bad welds in the field, but that could rise.

Officials with the city’s Department of Transportation Services, Hitachi and HART plan to walk the rail tracks to document every poorly welded switch plate, Kahikina said.

“We’re still trying to figure out how many,” she said.

Councilwoman Tsune­yoshi, among untold others, will be watching all of the efforts to solve the latest problems and ensure future passengers that they will be safe riding rail.

“It’s very concerning and I hope we find clarity soon,” Tsuneyoshi said. “We’ll see what else unfolds.”