Mayor Kirk Caldwell, former U.S. Rep. Charles Djou and former Mayor Peter Carlisle criticized one another for their respective positions on rail but failed to provide specific plans of their own during a forum Tuesday sponsored by the Rotary Club of Honolulu.

The major takeaways from the forum, held at the Japanese Cultural Center of Honolulu’s Manoa Grand Ballroom:

>> All three candidates want the rail project to span the entire 20-mile route to Ala Moana, and are willing to try to tap federal transit dollars and the private sector for necessary funding.

>> While experts now say the $6.8 billion in projected revenues will not be enough cash under current funding mechanisms to get the rail project past Middle Street, all three agree they do not want to raise property taxes to pay for construction to Ala Moana, but offered no real plans to pay for it.

>> Djou differs from Caldwell and Carlisle in that he vowed not to seek an extension of Oahu’s existing 0.5 percent surcharge on the general excise tax to pay for rail to get to Ala Moana, and appears more willing to go back to the drawing board for the Middle Street-to-Ala Moana segment. The other two candidates would prefer to see the steel-on-steel technology continue.

Carlisle said, “It would be absolutely nonsensical under any circumstances to stop what was promised, which was from Ala Moana back to Kapolei, and Kapolei to Ala Moana.” The former mayor said he would seek federal dollars to cover the shortfall.

Djou maintains that the project should be modified to match financial realities. “We have to be open to any alternative here to change our mass-transit objectives to get people from the west side all the way not to Ala Moana, but to (the University of Hawaii),” Djou said. “But we have to do it within reason and with a budget we can afford.”

The city should “stay the course” with the current technology, which has been proven reliable elsewhere, Caldwell said. Changing the technology now, he said, would require a new environmental impact statement and a new route, and could pose legal challenges — changes that could set back the project another 10 years and cost an unknown amount of money. “We have the trains, we have the rail line in place,” Caldwell said.

Djou said he supports the idea of having the project run at ground level from Middle Street to Ala Moana. “We need to look at changing the route and the system. If we don’t, this system will consume us. I am fully supportive of looking at any reasonable alternative here that can achieve our transit objectives without breaking the bank.”

Carlisle said an at-ground line would “invite … suicides, interactions with cars, and splits downtown Honolulu right in half with an impenetrable barrier.” He added, “Putting this thing on the ground is a disaster.”

While above the ground is expensive, “we have a way to pay for it,” Caldwell said. “If it’s on the ground, it can’t go any faster than the fastest car or bus.”

Djou said Caldwell’s plan to take Middle Street “and then figure out the rest after the election isn’t accountable. It’s not working.”

The mayor said Djou has yet to pinpoint a plan to extend the project to Ala Moana. “That is not being honest with all of you,” Caldwell said, nodding to the audience. “How is he going to fix it, and where is the money coming from to do so?”

After the forum Carlisle said, “We need to look at every possible (funding) source” to get rail to Ala Moana except raising property taxes. He said he would support an extension of the excise tax surcharge because “we’ve already got it going.”

Caldwell said he is the only one who has a solution for additional funding.

“There are multiple sources, and one is talking to the federal government,” he said. “They’ve said, ‘No, not right now.’ They said, ‘Until the election is finished, we can’t make that commitment because there will be a new administration (in the White House).’” Caldwell is also hoping that developers and landowners along the rail line will either build rail stations or provide financing to the city.

Djou said it’s Caldwell who “has no clue … and has no plan whatsoever” to fund the rail to Ala Moana. “I think the realistic solution to do that is to look at putting the system on the ground, including looking at perhaps … light rail or … bus rapid transit.”

The mayor’s race has drawn eight other candidates, none of whom have held elected office or have as high a profile as Caldwell, Carlisle or Djou.

The primary election is Aug. 13, although absentee mail-in ballots have started being delivered to Oahu voters. A candidate from the field of 10 getting 50 percent of the votes cast plus one vote would be declared the winner. Otherwise, the top two candidates will face off in conjunction with the Nov. 8 general election.