The company building train cars for the Honolulu rail line must retrofit 24 cars that have already arrived in Hawaii to make them more fire resistant, according to the Honolulu Authority for Rapid Transportation.

A sample from one of the rail cars being produced for the city’s $9.2 billion transit project failed roof and floor fire testing in Texas in February, and a car shell was supposed to undergo retesting in Italy this week to determine whether the first results were valid.

In follow-up testing this week of just the roof of a car train, the roof passed. However, after reviewing those test results, Hitachi Rail Honolulu Joint Venture opted on Tuesday to retrofit the floors of the Honolulu rail cars with a thin layer of stainless steel to ensure they will also pass the fire testing, HART officials said Thursday.

“They wanted more margin on the floor, so they just made a decision to go to the stainless insert as the most optimal solution,” said Andrew Robbins, executive director of HART. The retrofits will be done at the contractor’s expense, and Hitachi will also absorb any additional manufacturing costs for new cars, he said.

Industry standards require the roof and floor of rail cars to withstand flames for 20 minutes, an interval that is supposed to give passengers an opportunity to evacuate in the event of an accident and fire.

Fire testing of the car floor with the stainless steel retrofit in place will be done late next month to confirm it meets those requirements, HART officials said.

Each extra plates under the Honolulu cars will be about one-sixteenth of an inch thick, and will add about 190 pounds to the weight of each car.

Hitachi Rail will need to retrofit the rail cars that already have been shipped to Hawaii, and also incorporate the extra steel floor plate into the manufacture of the rest of the cars Honolulu has ordered to make sure they meet federal safety requirements, Robbins said.

Rail officials said they are not sure if the rail cars will be retrofitted in Hawaii or shipped to California to have the work done.

Ansaldo Honolulu JV won a $574 million contract with the city in 2011 to manufacture 80 Honolulu rail cars and develop and install the driverless rail operating system. Ansaldo was later acquired by Hitachi, and also has an $830 million contract to operate and maintain the Honolulu rail line for 14 years.

The floor and roof of the Honolulu rail cars are similar in design to another car manufactured by Ansaldo that passed a more stringent fire test, which is why the company didn’t believe the fire testing for the Honolulu cars needed to be completed earlier, HART officials said.

New entrance approved

In other business, plans to install a new entrance to the Waipahu Transit Center on the makai side of Farrington Highway for $6.44 million won approval from the HART board Thursday. HART staff said money for the change order will come from rail’s contingency reserves, and will not increase the overall cost of the project.

That makai entrance to the rail station was part of the original design, but was dropped in 2013 as a cost- cutting measure, said In-Tae Lee, deputy director of engineering and design.

Then the Honolulu City Council passed a resolution in March asking HART to work with the city to find a way to restore the entrance, and HART agreed to restore it.

The new entrance will improve access to the station and transit center, improve the flow of some bus traffic and encourage transit- oriented development in areas makai of the station, Lee said. HART still needs to acquire a small piece of property in the area to meet flood control requirements, which will add to the $6.44 million cost of the change, he said. That additional cost will also come from the rail’s contingency reserves.

Bird deterrents

The rail board on Thursday also approved a plan to spend $1.39 million to design and install measures such as netting and spikes to keep rats, birds and other wildlife out of the inner cavities of the 20-mile guideway, and also keep birds from perching above station areas that will be frequented by rail passengers.

Frank Kosich, director of rail design and construction for HART, said crews running cables inside the rail structure late last year reported pigeons and at least one non-native barn owl had been nesting in three areas of the guideway and depositing droppings in exposed areas of the structure.

Those droppings were “exposing workers to a potential for a health hazard,” Kosich said.