The city Department of Emergency Services dedicated six new ambulances Monday.

The new rigs will replace ambulances in Ewa Beach, Wai­pahu, Aiea, Wai­lupe, Kai­lua and Li­liha, Emergency Services spokes­woman Shayne Enright said.

Ewa-area ambulances have doubled their mileage since the closing of Hawaii Medical Center-West in late 2011, Enright said. Ambulances in the Li­liha area also were saddled with a heavier workload after Hawaii Medical Center-East closed in January 2012, she said.

The ambulances being replaced all have at least 100,000 miles on them, Enright said. A typical ambulance lasts about three years, but the ones being replaced have reached the end of their life spans in half that time, she said.

The state, which contracts with the counties for emergency medical services through the Department of Health, paid the estimated $190,000 tab for each of the six new rigs, she said. Each will include about $85,000 in electrocardiogram machines, ventilators, pumps, computers and other equipment.

City Emergency Services Director Mark Rigg said in a statement, "The Emergency Medical Services Division is committed to caring for those who are sick and injured in our community and these six new ambulances will help us continue to provide life­saving services."

The old ambulances will be kept as relievers or spares.