The Tube Takes On the Sea in Battle to Save a Carlsbad Beach

Times Staff Writer

Along a 1,000-foot stretch of Carlsbad beach that once was covered with cobblestones lies an enormous wormlike dike of sand-filled plastic called a Longard tube.

Behind this unsightly barrier rest tons and tons of precious sand, saved from theft by the winter's windblown high tides, which drain away the grains, sometimes to return them in the spring.

The Longard tube is one of the latest in a long line of hoped-for panaceas embraced by this coastal region in an effort to preserve one of its most precious assets, the sandy beaches that attract hundreds of thousands of visitors every year. But the jury is still out on whether this ungainly device is living up to its reputation as an innovative, relatively low-cost answer to beach erosion control.

"I'd call it a moderate success," said Bob Wojcik, a city senior civil engineer who, like a lot of other Carlsbad residents, makes trips to the beach to see how the sand-filled behemoth is faring.

"Of course, it hasn't really been tested yet," he cautioned. "We really haven't had a severe winter storm like the one that did in Del Mar's tube" since the Carlsbad structure was installed in the spring of 1983.

Three towns south, in Del Mar, the only reminder of the city's brave experiment at beach erosion control is a tattered piece or two of the sturdy fabric sticking out of the sand at low tide.

Del Mar's Longard tube worked well until the winter of 1982-83, when high tides and wind-driven waves combined to breech the barrier and turn it from an asset into a problem.

"It wasn't the storm that destroyed it. We did that," Del Mar City Manager Bob Nelson confessed. The waves rose high enough to break over the tube and dump water behind it, he explained. That water, seeking to return to the ocean, created a "lateral flow" that began eroding the beach at each end of the 660-foot-long tube.

"When I saw what was happening, I told the guys: 'Take her out,' and they did," Nelson said. So, early in 1983, the $100,000 experiment died at the age of 2.

"No, we'll never do it again," Nelson said. "It had a high potential for failure, and it did."

To the north in San Clemente, owners of a mobile home park installed a Longard and had nothing but problems with it.

"It was an obvious failure," Wojcik said. Its sponsors had nothing printable to say about it, he added.

In an effort to educate the Carlsbad property owners, Wojcik convinced some of them to visit the San Clemente installation to show them that the tube was not a perfect cure-all. The effect of the visit was "amazing," Wojcik recalled. The Carlsbad contingent appeared, if anything, even more eager to pursue their beach project, he said.

The Carlsbad oceanfront landowners, with a little help from the city, went ahead with their plans despite the failure of the Longard technology to the north and south. In May, only a few months after Del Mar's tube was destroyed, 16 property owners along Carlsbad's Ocean Street anted up $130,000 for a Longard tube. The city chipped in $10,000 to finance part of the construction.

"We told the property owners that the city would take the lead and handle the installation of the tube," Carlsbad City Manager Frank Aleshire said. "After that, everything--the liability, the upkeep and repairs--was up to them."

Tony Howard-Jones, leader of the groups of property owners who tend the sausage-like Longard, said that he and the neighbors have faithfully kept it in shape, painting it with epoxy and sand at intervals to strengthen its coating, and patrolling to keep vandals from damaging it.

However, about eight or nine months ago, someone or something attacked the tube, slitting its outer covering and allowing its sandy fill to spill out onto the beach. More than 200 feet of tube was lost.

"It was almost certainly vandalism," Wojcik said. "One evening it was there and the next morning it wasn't. There was not the sort of weather that could have done it."

Nature and man are the Longard's enemies, Carlsbad and Del Mar officials agree. And Nelson can spin tales by the hour about the Del Mar tube's adversities, as well as some humorous moments.

In the summers, when the tube was almost completely covered with sand, beachgoers wreaked havoc by building bonfires above it, sometimes unwittingly, sometimes not.

The heat conducted by the sand to the tube melted its plastic covering, which Nelson described as similar to double-knit suit material except that the strands are "as big around as a baby's finger." Lifeguards then were assigned to sew patches over the holes in the tube covering, a very unpopular duty.

Once, a wayward bulldozer scooping sand out of the ocean's way scraped its blade across the tube, opening a gaping hole. Nelson took the equipment operator to small claims court to recover the cost of repairs.

And, on one winter day, Nelson watched helplessly as storm waves launched some floating wood at the tube like a spear, each surge inflicting another wound in the tube.

Scientists from Scripps Institution of Oceanography analyzed the Del Mar tube and came to the conclusion that it failed because it was not seated on solid ground. Constant wave action eroded the sand base of the tube in spots, allowing the bulky structure to sink unevenly and permitting the waves to infiltrate and attack the Longard at its weakest points.

In Scandinavian countries, where the Longard tube was devised and first used, its success rate was near 100%, Scripps scientists reported, leading them to conjecture that the less-than-perfect record of the Longard along the Pacific coast is due to a difference in wave action between the Atlantic and Pacific oceans and the lack of solid rock or another firm base along most Southern California beaches.

"It is a good idea that should have worked better than it has," Aleshire summed up in assessing the Carlsbad experiment. Perhaps, he said, if the property owners come up with the money, the 200 to 300 feet of Longard that succumbed to apparent vandalism can be patched, repaired and restored to duty.

In addition, half a dozen other methods of retaining sand are being tested along the city's beaches, Aleshire said.

Gunnite has been applied to sections of the beach where it has hardened to a cement-like finish; artificial seaweed installation is under consideration for dissipating the surge of the waves offshore, and the more traditional method of placing boulders on the beach to form riprap barriers is being tried.

And soon, the city will be holding hearings on a proposed $4 million seawall to be financed with state and city money in yet another effort to save the city's beachfront.

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