Cheaper Braces No Savings for MTA : Transportation: The agency did not demand financial concessions when it allowed a contractor to use less costly wood braces instead of metal, records show. The material is blamed for contributing to the sinkage in Hollywood.

Officials of the Metropolitan Transportation Authority demanded no financial concessions when they permitted a contractor to use cheaper and inferior building materials for the bracing of subway tunnels under construction beneath Hollywood Boulevard and Vermont Avenue, records and interviews show.

Engineers working on behalf of the MTA allowed the contractor to use wood wedges instead of metal struts for the bracing. But officials did not require the contractor, Shea-Kiewit-Kenny, to compensate the transit agency for the resulting savings.

The wood wedges failed within a 200-foot-long section of Hollywood Boulevard last month, and project officials have said that the crushing of the wood helped cause significant surface sinkage in the area.

Andrea Greene, an MTA spokeswoman, said agency officials stand by their decision two years ago not to seek a credit from the contractor for its substitution of the less-expensive wood bracing. “The (agency) was not eligible for a credit in this case,” Greene said. “The bid documents called for structural steel or other approved struts. The contractor provided an approved alternative.”

Shea-Kiewit-Kenny won the contract to construct 12 miles of twin tunnels connecting Wilshire Boulevard with Hollywood Boulevard two years ago with a bid of $165 million.

After Times inquiries last week, MTA Chief Executive Officer Franklin E. White announced Monday that tests of the wood wedges have found that the material “failed to meet its specified strength.”

White said he intends to retain outside specialists by the end of the week to help investigate why the wood was not as strong as it was supposed to be. He also said he would review the decision to substitute wood wedges for metal struts, which were required originally by the contract.

Representatives of the contractor, Shea-Kiewit-Kenny, did not return calls seeking comment. They previously have declined to discuss any of their work on the subway.

Metro Rail contract documents show that when a contractor substitutes a less-expensive material “in comparison with the product specified,” the company should propose “equitable adjustment and credit” to the transit agency.

Other contractors reached by The Times said that the substitution of wood wedges for steel struts to fill expansion gaps in the outer concrete tunnel shell provided a cost savings.

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For instance, the contractor who submitted the second-lowest bid for the work, Tutor-Saliba Corp., based its proposal on the assumption that metal struts were required, according to company President Ronald N. Tutor. “We bid it on that basis,” Tutor said.

Another contractor with Los Angeles subway experience, Michael L. Shank, said that before he built 15,000 feet of tunnels now open to passengers Downtown, between Pershing Square and MacArthur Park, he considered and then rejected the use of wood wedges in the expansion gaps.

Shank said he estimated at the time that the wood wedges would have cost a maximum of $20 per four feet of tunneling, compared to about $60 feet for metal struts.

Shank said he decided not to use the wedges because he did not believe any wood product would meet the strength requirements. “We just could not satisfy ourselves that it would calculate to hold the loads,” Shank said. “Nor did we think the (transit agency) would approve it because we couldn’t demonstrate that it would hold the loads.”

Shank and Metro Rail officials said his company was required to test, to the point of destruction, the metal struts that would be used to demonstrate their strength.

Engineering experts, including Prof. John F. Hall of Caltech, told The Times that the hardwood oak wedges proposed as a substitute for the metal struts in Hollywood “appear to be inadequate to bear the full weight of the soil.”

The wood does not have the compressive strength of 1,500 pounds per square inch assumed under the contract revision, according to experts. Oak typically has less than half that much strength.

Tunneling along Hollywood Boulevard has been shut down since Aug. 18. The problems that two days later forced evacuation of one of the twin tunnels are the subject of investigations by local and federal officials. The subway work is financed with federal, state and local funds.

It has yet to be determined whether the contractor or the transit agency will have to pay for what are expected to be millions of dollars of repairs to the damaged tunnels, to the street and to buildings within a nine-block-long area of Hollywood Boulevard.

Meanwhile, the Los Angeles City Council on Tuesday approved spending $50,000 to hire its own engineer to review the plans for preventing any further problems from subway tunneling beneath Hollywood.