By Mario T. Icari, Naval Facilities Engineering Command Southwest Public Affairs
SAN DIEGO (NNS) -- Naval Facilities Engineering Command (NAVFAC) Southwest, Naval Base Point Loma (NBPL), NAVSEA Southwest Region Maintenance Center (SWRMC), and SPAWAR Systems Center Pacific (SSC PAC) conducted a rapid engineering pier assessment Feb. 11 and 12 at Naval Base Point Loma (NBPL) south submarine pier as part of the nation-wide, CNIC exercise Citadel Shield 2015.
"The exercise overall was an excellent opportunity to demonstrate how various teams from across Navy Region Southwest can come together under a common mission to support the base and the warfighter and get the job done," said Lt. Cmdr. Daniel Lutz, NAVFAC Southwest production officer.
As part of the annual Anti-Terrorist Force Protection exercise, NBPL was the center of gravity for Navy Region Southwest due to a live simulated infiltration of two active shooters and a suicide bomber on the base. In response, NBPL initiated THREATCON Charlie the morning of Feb. 11. As the scenario unfolded, the suicide bomber detonated a bomb on the south submarine pier.
Once the pier was secure, an initial damage assessment was made by NAVFAC Southwest junior officers assigned to Public Works Department NBPL. The simulated damage included a small crater from a bomb detonation on the surface of the pier that was two feet in diameter and six inches deep with cracks radiating outward and loss of power to the moored submarine and a building on the pier.
The findings of the initial damage assessment prompted NBPL Emergency Operations Center (EOC) to request support from the Regional Operations Center (ROC). In turn, Region resourced the base with surveying assets from SWRMC and SSC PAC who provided reach back and waterfront engineering support via NAVFAC Southwest Coastal Integrated Product Team (IPT).
SWRMC and SSC PAC Remotely Operated Vehicle (ROV) teams were deployed to the south pier and fell under the direction of the Civil Engineer Corps Officer on site and NBPL EOC. The purpose of the newly formed assessment team was to evaluate NBPL's south pier structural integrity and assign restrictions to the base commands operating on the pier. The assessment team also recommended expedient repairs needed to the pier for maximum pier area cargo operation availability. Finally the team gave scope and cost estimates for a permanent repair to return the pier to its previous vertical and lateral load capacities.
SSC PAC employed their ROV first to quickly inspect the pier piling directly above the detonation with the highest probability to have sustained damage. The submersible was launched, controlled, and tethered from a small boat. This ROV is still in development with its primary mission being mine detection. Once the SSC PAC technician inputted a few simple parameters to locate and inspect the piling in question, the submersible then operated autonomously on sonar power.
"Fortunately for NAVFAC engineers, in the process of looking for a mine on a pier piling, the ROV can do a pretty good piling inspection," said Steve Koepenick, SPAWAR Systems Center Pacific representative. "This capability is unique in that the ROV can operate without human input and then retrace its steps without getting tangled under the pier. It can also inspect in water with zero visibility."
Minutes after the sonar inspection, the SSC PAC technicians created a 3D mosaic of the pile and proved that it was still intact and standing and that it had not suffered any major damage. Minor damage and cracking was indiscernible in the sonar image leaving NAVFAC engineers and the EOC with some unanswered questions.
SWRMC arrived on site shortly thereafter from Naval Base San Diego. They drove directly onto the south pier, around the simulated blast area, and setup their SeaBotix ROV equipment pier side. Their tethered submersible could navigate via onboard sonar and visually inspect via an underwater camera while Navy petty officers remotely controlled it. The SWRMC ROV provided a live video feed that was then broadcasted to the pierside operator as well as remote viewers. A dedicated webpage provided live video feed to the EOC, ROC, and higher headquarters as well as two waterfront engineers at NAVFAC Southwest Coastal IPT. This real-time video feed allowed subject matter experts to inspect the pier first hand and make more accurate determinations of the level of damage. In addition to the live feed, a chat function on the webpage allowed the waterfront engineers to chat with the operators and to give guidance as to where and what to inspect in real time.
By 9:00 a.m. on the morning of Feb. 12 the inspection was complete. The assessment team provided the EOC and NBPL leadership with their evaluation of the south pier's structural integrity and assigned a standoff restriction for vehicle traffic and weight handling equipment within 22 feet of the crater, and recommended high strength mortar for surface concrete as an immediate repair. NAVFAC Southwest Costal IPT also recommended a diver survey to inspect the underside of the pier directly under the blast location. They estimated this effort to take two to three days and cost approximately $30,000.