For more than 90 years, the old Royal Hawaiian Groin had helped protect Waikiki Beach in Honolulu, but its deteriorating condition required quick action. In 2020, Hawaii’s Dept. of Land and Natural Resources broke ground on its replacement, a 175-ft-long hybrid structure half the size of the original groin and made of granite armor stone and reinforced concrete.

The $1.4-million project was originally scheduled to be built during winter months, when the tide and swells on the south shore of Oahu are calmest. But when the beaches closed in March 2020, the DLNR asked contractor Kiewit Infrastructure West Co. to start work early. The project team also altered the work plan to transport and stockpile the stone while the beaches were closed, thus reducing safety risks to the public. Construction was challenging in the higher surf conditions, but the team completed the groin in July of that year, ahead of schedule and on budget with zero safety incidents.

Since the groin was half a mile from the only access point, the 2,000 tons of stone required for construction were hauled in off-road dump trucks more than half a mile down the soft sands of Waikiki Beach. The team built nearly 600 ft of a reinforced steel-plate roadway on the beach to haul the stone. But when the concrete was placed in mid-July, the beaches had reopened and building an access road would be a major safety hazard and an inconvenience to the public. The project team instead used the Royal Hawaiian’s loading zone to pump concrete to the site.