Local rail officials and Hawaiian Electric Co. say they’ve agreed to a cheaper fix for many of the utility-line clearance problems that have plagued Oahu’s elevated transit project, saving about $140 million.

Under the new $61.5 million plan, which was unveiled at Thursday’s Honolulu Authority for Rapid Transportation board meeting, most of the overhead power lines running along the rail route’s first 11 miles from East Kapolei to Aloha Stadium would stay put, and HECO crews would work on them using new, specialized trucks and cranes.

The plan avoids a costlier, $200 million worst-case scenario for HART and the city, in which all of those lines would have been relocated underground to avoid rail’s concrete pathway.

Instead, the city will pay for the new equipment and the cost to put just some of the lines underground.

The agreement follows about four years of wrangling between HART and HECO to resolve the clearance problems. By 2015 they posed the “most significant risk” to rail, according to Jacobs Engineering, the independent firm overseeing the project.

“This was an expert-level puzzle, and solving it took a lot of people at Hawaiian Electric and HART exploring options and then testing solutions out in the field,” said Jim Kelly, HECO’s vice president for corporate relations. “There are still some areas that will be challenging and some clearances that will be tight, but we think we can make it work.”

Thursday’s cost-saving plan does not include the overhead power lines that run along the narrow Dillingham Boulevard corridor, however. The city will still have to pay an estimated $70 million to relocate those power lines underground to get them out of the way, according to Brennon Morioka, HART’s deputy director.

The semi-autonomous rail agency aims to save more costs and avoid putting the lines — currently on nine 138-kilovolt poles between Aloha Stadium and Middle Street — underground. Doing so largely depends on HART securing the land easements it needs from the Navy near those poles, Morioka added.

HECO had warned rail consultants in 2009 that its workers would need clearances of 50 feet to safely access high-voltage power lines near the guideway, but the issue was neglected until 2013. The city started building rail shortly afterward without a solution. Since then the problem has become a top priority for rail officials — and they’ve budgeted an added $300 million to deal with it.

Thursday’s utility plan represents a rare instance of good budget news for the island’s cash-strapped project, which has seen its projected cost nearly double from $5.26 billion in 2014 to about $10 billion today.

The roughly $140 million that HART expects to save from its utility-relocation budget will go into rail’s contingency fund, Morioka added.

HECO needs as much as 50 feet of clearance for the “bucket” trucks that carry its maintenance crews to gain access to overhead lines, according to the local utility. Rail and utility officials since 2014 have been testing other trucks and equipment designs that might safely give HECO’s work crews the access they need to the power lines on the rail route’s west side.

Those stretches of the route — along Kualakakai Parkway, Farrington Highway and Kamehameha Highway — offer enough space that special equipment might solve the problem more cheaply than relocating power lines.

The crews “started reviewing everything on a pole-by-pole basis,” Kelly said Thursday.

HART and HECO officials traveled to Colorado to test some equipment, Morioka told the HART board Thursday. Eventually, the two entities agreed that specialized Altec-brand bucket trucks and Phoenix-brand cranes would work for most of the overhead lines on the west side.

Dillingham Boulevard remains too narrow for that solution to work, however, Morioka said. It’s part of rail’s final 4-mile stretch heading into the crowded urban core, a stretch that has seen its projected costs swell by nearly $1 billion.

The city will also have to cover the costs for HECO to find additional storage for the new trucks to serve the power lines along the rail guideway, Morioka said. HART doesn’t yet have an estimate for that cost, he added.

Rail leaders, including Honolulu Mayor Kirk Caldwell, are asking state lawmakers for another rail-tax extension to rescue the transit project.