Multiple experts across the different groups responsible for Honolulu’s transit tracks have strong misgivings about their unusual crossing design, echoing the concerns that a former project consultant raised this summer, according to a newly released internal city memo.

Typically, rail transit systems only make limited use of the type of crossing point that’s being installed on Oahu, known in the industry as a “flange-bearing frog,” according to the June 9 memo written by an employee at the city’s Department of Transportation Services.

However, the Honolulu Authority for Rapid Transportation is relying almost entirely on flange-bearing frogs as it builds the rail line across Oahu’s southern shore.

“We are simply at a loss on how this whole situation has evolved,” the DTS memo states. “HART is doing something none of us have ever seen before. Now we are concerned that we will inherit their problem that will cost the taxpayers tremendously for years.”

Rail construction at the Daniel K. Inouye International Airport.
Crews work on the track and crossing points near the Honolulu airport. The system’s unusual use of flange-bearing frogs at those crossing areas has multiple parties responsible for the system’s wheels and tracks concerned. Cory Lum/Civil Beat/2022

The memo forewarns that approach – and the very narrow track tolerances that accompany it – will cause a maintenance nightmare going forward.

HART released the internal city document on its website ahead of a board discussion on the matter slated for Thursday.

It’s not clear who wrote the memo. DTS is poised to take control of rail’s operations and maintenance once the first 10 miles and nine stations open. The agency’s director, Roger Morton, was unavailable Tuesday for comment.

The memo lists DTS’ senior operations and maintenance manager, Steven Bose, and its track compliance officer, Yifeng Mao, as among the six inspectors, managers and compliance officers working on track issues who were “surprised” to see HART use that frog design.

All of them have expressed their misgivings about using the flange-bearing frogs on rail’s mainline track, according to the memo.

Three of the those listed work for Hitachi Rail Honolulu, which is building the rail line’s signaling, communications and driverless trains for HART and the city.

One of the Hitachi managers called the suggestion that they replace the frogs “the smartest thing he has heard since he has been on the island,” according to the memo.

The final person that the DTS memo lists is David Walker, a rail industry veteran who worked on the Honolulu project as a track consultant with rail contractor Stantec until February. Stantec reassigned Walker back to the mainland U.S. after he repeatedly insisted to HART that it swap out the flange-bearing frogs with the more commonly used tread-bearing frogs.

The change, Walker asserted, would save enormous sums of cash in long-term maintenance. It would also avoid system malfunctions and reduce what he described as a very slim chance of derailment after several years in operation.

In July, the local rail agency dismissed Walker’s concerns in a statement to Civil Beat as “the opinions of one individual” that didn’t reflect the views of his employer.

Walker has since retired.

HART Executive Director Lori Kahikina declined through an agency representative Tuesday to comment on the newly released memo, citing the board’s pending discussion.

David Walker speaks to Marcel in the conference room at the Civil Beat office.
Former rail consultant and track expert David Walker raised many of the same concerns detailed in the newly released DTS memo. Cory Lum/Civil Beat/2022

It’s not clear whether she or anyone else at HART had seen the DTS memo when Civil Beat asked about Walker’s concerns earlier this summer.

Walker has said that the rail agency knew that others working on the project shared his misgivings with the crossings and the maintenance and potential safety challenges they posed.

“These maintenance tolerances are too restrictive and unmaintainable,” the June memo states.

The DTS author further says they have “zero confidence” in the frogs’ ability to perform as needed, and “thus we will see many speed restrictions and our customers will suffer undesired delays.”

The memo also states that 67% of train derailments occur at switch points, and that “we are heading down a path that no one has ever done before” based on the frog design and speeds involved.

It recommends replacing many of the already installed flange-bearing frogs with the standard tread-bearing ones used in other rail transit systems. Tread-bearing frogs support the main surface of a wheel, while the flange-bearing frogs used in Honolulu support the wheel’s larger edge.

“The consequences in not moving forward with the replacement of the turnout FBFs (flange-bearing frogs) are too great for DTS to incur especially with the system opening months away,” the agency’s memo states.

The comments from DTS and Hitachi largely reflect Walker’s own conclusions from when he worked on the project separately for Stantec.

Pumping The Brakes?

The memo’s release comes amid HART’s trial running phase, which must be successfully completed before passenger service along the line’s western 10 miles can begin.

That trial started in late August and will last at least 90 days. The city now aims to launch that much-anticipated interim rail service early next year.

Stopping to replace the frogs with the more standard and widely accepted design could push that opening back about another year, Walker estimated Monday.

Any such change in frogs would also come after HART and the city spent well over $500,000 on an outside consultant, Transportation Technology Center, or TTCI, to verify that Honolulu’s driverless trains could run safely over the existing frogs at the speeds needed.

“That’s why HART doesn’t want to do it right now,” Walker said Monday.

Plus, in order to use the existing frogs, HART has already started to replace the trains’ wheels with wider, custom-designed ones that will fit Oahu’s unique track layout. It’s not known how much the replacement wheels will cost, and it hasn’t been determined whether the city or Hitachi will pay for them.

Rides ‘Getting Worse, Not Better’

The DTS memo says some of the city agency’s most pressing questions to TTCI regarding its analysis of the frogs “were simply disregarded” by the consultant.

Specifically, DTS wanted to know why the Colorado-based consultant did not consider an FTA-accepted formula used to calculate how long the frogs’ built-in ramps should be.

Based on that formula, developed by another rail industry firm, Transit Cooperative Research Program, Honolulu’s frogs are too short and steep. It’s an issue that Walker raised this summer.

The version of the memo released by HART includes responses from TTCI. The consultant said that it did consider the city agency’s comments for its final report but it “did not use all DTS suggestions.”

“TTCI was not asked to design the frogs nor recommend an optimal ramp rate” for them, the consultant wrote.

Walker described that comment as very telling.

“They had a very narrow scope to go by, and by that narrow scope they could only come to one conclusion,” he said, which was to clear use of the frogs at the desired train speeds.

The memo also raises what it calls “new ride quality concerns.”

During test rides in May, DTS personnel encountered “noticeable and at times uncomfortable side-to-side train movement” along the main track, according to the memo.

“I don’t recall our previous train ride … being this bad. I also don’t think this is a safety concern,” the DTS employee said. However, they did think it would cause wheel and track maintenance issues.

“It seems that as the system is wearing in with the newly cut (wheels), it is not wearing in a stable way,” the memo adds, “and the side-to-side motion and resultant wear is getting worse, not better.”

TTCI responded that the uncomfortable motion during the ride is a result of the system’s tight gauge problems, separate from the frog issues.

Walker agreed. The motion issues will persist even if the frogs are replaced, he said Monday.

Board Wants More Details

It’s not clear what prompted the HART board to take up the frogs matter during its latest Project Oversight Committee meeting.

However, in July, the agency’s board chair, Colleen Hanabusa, told her colleagues she was surprised to learn of Walker’s concerns after reading his separate memo on the frog saga in the media.

HART CEO Lori Kahikina
Lori Kahikina: DTS was “in agreement” to keep rail’s existing frogs. David Croxford/Civil Beat/2022

“I’m going to ask that we as a board get this kind of information to us,” Hanabusa told HART staff.

In subsequent meetings, Kahikina has reported that the frog issues have been fixed.

She has declined requests to discuss the matter, although she and HART Deputy Director Rick Keene fervently dismissed Walker’s concerns as unfounded on local radio talk show host Rick Hamada’s program once they became public.

“This individual that is being touted as a whistleblower … he just did not like the joint decision that all the smart people in the room” made, Kahikina told Hamada. “We’re not handing an O&M (operations and maintenance) nightmare to DTS. They were in agreement with the decision” to ultimately move forward with flange-bearing frogs.

The board’s discussion on the newly released DTS document will be held 10:30 a.m. Thursday at HART’s board room on the first floor of Alii Place.

Read the memo here:

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