By Pat ShermanDespite rumors that the city was having concerns about the safety of its new lifeguard tower at La jolla Shores — specifically the cantilevered arm supporting its observation tower — Rick Espana, a senior associate at Roesling Nakamura Terada Architects, which designed the $3.8 million facility, said lifeguards and beachgoers have nothing to worry about.
“The arm itself uses high-strength concrete and can carry a load of up to 3,200 pounds — not including the (observation tower),” Espana said. “The tower itself was only designed to hold three people in terms of operation, but you could probably quadruple that and you’d still be fine.”
The interior of the concrete arm features epoxy-coated, steel rebar. “There’s quite a bit of it too,” Espana said. “We worked with our structural engineer pretty closely to make it all fit and work. epoxy-coated rebar, basically, is rebar that will not corrode over time.”
espana said the crumbling, condemned lifeguard tower at Children’s Pool beach — slated for demolition by month’s end — is being replaced in large part due to corroded rebar.
The high-strength concrete used in the new Shores tower is made to withstand 7,000 pounds per square inch.
“It’s extremely strong and extremely durable; it should last many, many years,” espana said, adding that it meets current building codes for a high-seismic, coastal area.
“During construction we had a couple of tremors after the arm was formed and there were no issues,” he said. “We don’t have any concerns about that.”
Of the new 1,485-square-foot tower, City of San Diego Project Manager Jihad Sleiman concured, “We strongly believe that we have a super-safe building there.”
The existing, 850-square-foot Shores’ tower will be demolished by june 28, the city said. An evaluation of the new tower’s features and safety considerations — produced earlier this year by students with UC San Diego’s Department of Structural Engineering (which can be viewed here at
bit.ly/shorestowerstudy) — suggests that ultrasonic testing, impact echo testing and infrared thermography should be used periodically as tools to assess the tower’s health. “Metallic elements such as the stairs, girders, and columns are all prone to cracking, rust, and corrosion over time,” the report states, in part. “It is proposed that over the life of the structure, trained ultrasonic testing personnel periodically check all metallic elements for significant defects and record data such as the location and severity of found defects. ...
“The new La jolla Shores Lifeguard Tower has a lack of structural redundancy. Because of this, the structure is vulnerable to high deflections if any cracks are present. It is important to monitor these deflections and cracks over time in order to make sure the structure remains within its allowable deflection limits.”
New Children’s Pool tower updateSleiman said the city is still waiting for the national Oceanic and Atmospheric Administration to issue an Incidental Marine Mammal Harassment Permit before the demolition of the existing Children’s Pool lifeguard tower can proceed. The permit is required in case construction causes an unintended disturbance to seals on the beach.
“We promised all the groups here that we are not going to start this project unless we have that permit in hand,” Sleiman said. “We are very, very committed to this. We are not going to do work during pupping season, and we are not going to start if we don’t have that permit.”
In the meantime, Sleiman said, the city will set up two temporary lifeguard towers along the coast — one about two blocks south of Children’s Pool, and the other on the southern edge of ellen Browning Scripps Park.
The existing trailer used as a lifeguard office will be placed atop several street parking spaces at Children’s Pool until the new tower is built, Sleiman said.