OCEANSIDE —— Trying to build a private bridge over the Sprinter light rail line has meant nothing but frustration for a local nursery company.

"It's really been a disaster for me," said Mark Collins, owner of Evergreen Nursery Inc. "I was perfectly willing to spend the $600,000 it takes to build the bridge. I even saved up for it."

Evergreen has four nurseries in San Diego County, including one on Oceanside Boulevard just east of El Camino Real. The 87-acre property straddles the North County Transit District's planned Sprinter railway, with two thirds of the acreage accessible only by using a private railroad crossing.

When the transit district rebuilds the section of tracks through the nursery, it plans to close the private crossing. Collins said he understands that he has only temporary rights to use the crossing, and that the district has the legal right to close it at any time.

To maintain access to the bulk of his nursery property, Collins said he planned to build a 180-foot bridge over the tracks using surplus flatbed railroad cars. He said the transit district initially approved the bridge years ago, but has since withdrawn its support.

"I've already spent over $100,000 just in engineering and I have submitted six sets of plans. They were all wrong for some reason," Collins said.

Recently, private railroad crossings along the Sprinter line have become a hot-button issue in Oceanside. On July 30, residents of the Cavalier Mobile Estates, a 348-unit mobile home court at Oceanside Boulevard and I-5, learned they would be asked to pay to upgrade the private crossing that is the only entrance into their homes.

Upgrades would cost an estimated $445,000. The move has spurred the Oceanside City Council to consider making Cavalier's entrance driveway a public street, hoping to force the transit district to pay for the crossing.

Tom Kelleher, spokesman for the transit district, said Thursday that railroad engineers have decided that the proposed bridge is simply not appropriate to cross the Sprinter line, which will carry 64 passenger-train trips per day.

"Our engineers won't accept that," Kelleher said. "We have to decide what's safe and what's good for our railway and we have made the decision that a railroad car bridge is not it."

Kelleher said transit district engineers have not precluded Evergreen from building a bridge to span the Sprinter tracks. But he said any bridge that is built must be constructed so that a second track can be added alongside the single set of steel rails that will be installed by 2007.

"I think the crux of it comes down to the fact that we want Evergreen to build a safe and strong bridge and one that allows us to do double tracking in the future," Kelleher said.

Collins said he's frustrated that he has had to face a constantly changing set of requirements for his bridge from transit district engineers who designed the Sprinter. He said his initial railroad car design was initially approved by the transit district but later derailed.

"I have it in writing," Collins said. "If I had known that (they would not approve a railroad car bridge) I wouldn't have waited five years and spent $100,000 trying to build it."

He said requirements for the bridge have constantly changed over time, making it impossible to have his engineer design a bridge that will gain approval. He said the transit district had a moral obligation to tell him what he could build from the beginning.

"My belief is don't let me go down the river and then tell me, 'This is not a river you can go down,' " Collins said.

Faced with losing access to much of his property, Collins said he has hired two lawyers in case he must press the matter in civil court. He said he is willing to build whatever kind of bridge the district will allow.

"I'll pay for whatever they'll let me do," he said.

Kelleher said the district has already told Evergreen what kind of bridge it can build, though he could not specify exactly what kind of construction that would be.

"It's been abundantly clear to Mr. Collins what our engineers want," Kelleher said.

That statement made Collins laugh.

"They have told me everything but what I can build," he said.

Contact staff writer Paul Sisson at (760) 901-4087 or psisson@nctimes.com.