Parts of the rail guideway are cracking and snapping even before the first stretch is finished, and money-saving efforts may be behind the problem, new reports show.

Workers haven’t yet finished building rail’s first 11 miles of elevated path across West and Central Oahu, but the transit project is already showing defects in key components along the concrete guideway.

Years before any trains will carry commuters across the island, cracks are forming in the plastic padding used to give the train tracks a level surface, and strands in three of the tendons that help keep the guideway structure in place have snapped apart, according to reports issued by the Honolulu Authority for Rapid Transportation and the rail project’s federal oversight agency.

So far, only a small fraction of the metal strands running through the guideway and the so-called plastic “shims” that keep the tracks level have been reported damaged. But rail and construction officials are still working to confirm the root causes of both problems. It remains to be seen how much all the replacement parts and any work to avoid further damage will cost — and who will pay for it.

The latest snafus emerge publicly as HART and Kiewit Infrastructure West, the firm that’s building rail’s first 10 miles, acrimoniously spar in private over tens of millions of dollars in change orders, according to former project consultants with knowledge of the situation.

The HART board is slated to discuss the damage issues at its meeting today, the first to feature Mike Formby in the capacity of the agency’s acting executive director instead of as one of its most outspoken board members. Formby and board Chairwoman Colleen Hanabusa, who helped bring about former Executive Director Dan Grabauskas’ resignation, are both poised to exit HART before the Nov. 8 general election.

HART representatives did not respond to multiple requests for comment on the material defects Tuesday and Wednesday.

A Kiewit spokeswoman contacted Wednesday afternoon said the firm would not be able to respond in time.

Rail officials and Kiewit originally opted to use the plastic, narrow shims instead of a “plinth” — essentially an elevated concrete platform — because they estimated it would save more than $7.5 million along the project’s first 11 or so miles, according to a slide presentation that the board will review today.

However, the shims aren’t performing as planned, and Kiewit will have to make adjustments for them to suit the train tracks, the HART presentation states. Furthermore, since June workers have discovered that about 2 percent of the shims and electrical insulation along the tracks provided by Kiewit have cracks, the report added.

“Some of the thinner (blue) shims appear to be brittle and are cracking,” Jacobs Engineering, a firm hired by federal officials to oversee rail, wrote in its August report.

According to HART, Kiewit has said many of its “isolation pads” used to help contain electrical current “may not” have met the requirements for ultraviolet protection, and the firm has agreed to replace some 165,000 of them at no cost.

But HART is still waiting to hear back from Kiewit on the shims, the rail agency’s presentation states. Both parties have sent the materials to labs for independent testing and the results should be back by the end of September, the report added.

Also, since January workers have discovered snapped strands in three steel tendons that help hold the guideway together, according to HART.

After the problem was found, both HART and Kiewit hired their own forensic engineering experts. They determined that water had leaked through and corroded the strands that eventually broke.

In follow-up inspections, they’ve found potentially corrosive water in 26 other tendon ducts and “defective” grouting that’s supposed to seal and protect the tendon strands, according to the HART and Jacobs report.

Kiewit has since replaced 12 known “problem” tendons in the guideway, including the three that broke, the report stated. HART is still waiting on final reports from the construction firm and its own forensic consultant, Wiss, Janney, Eltsner, Associates Inc., before it decides what to do next.

Kiewit was awarded contracts in 2009 and 2011 to build rail’s first 11 miles. The first contract, to build along Farrington Highway, is six months behind schedule and slated to be done in March. The second contract, to build along Kamehameha Highway to Aloha Stadium, is a year behind schedule and slated to be done in April 2018, according to Jacobs Engineering.

Rail officials hope to partially open rail for service to Aloha Stadium in December 2019.

The entire 20-mile transit project is about five years behind schedule. Kiewit did not bid on the next stretch of rail construction to Middle Street.