Antlers Bridge Demolition

Ballard Marine Construction had been tasked with locating and removing unexploded ordnance (UXO) in the Sacramento River arm of Shasta Lake near the community of Lakehead, California. The unexploded ordnance consists of RDX Linear Shape Charges (LSC’s) ranging in size from 7-30 inches in length at 600, 900, 1200, and 2000 grains per linear foot. In addition to the LSC’s, Ballard commercial divers removed the prima cord (“pigtails”), non-electric booster caps and detonators.

The unexploded ordnance was a result of the “pigtails” at the connection point to the booster caps suffering from long-term exposure to water temperature fluctuations creating a water barrier, subsequently resulting in failure of initiation of the explosives. Approximately 250 of the 1288 LSC’s that were loaded on the Antler’s Bridge failed to initiate and required underwater recovery. Ballard divers recovered the unexploded ordnance and loaded them into recovery bags that were hoisted onto the deck of a barge and placed into a magazine for temporary storage. Ballard is also utilizing underwater metal detectors to locate explosives laying on the lake bottom, not visible due to sediment.

We are working under a California licensed explosives contractor (Dykon Explosive Demolition Corp) under prime contractor Tutor-Saliba.