St John still needs more volunteers to maintain a 24-hour service, in addition to seven who have already stepped forward.
The service has 12 volunteers, but needs another 12 to ensure the 24-hour service can continue without stress on its staff.
Six Meridian Energy Twizel-based staff put their hands up, and another person had volunteered since the shortage was first publicised about a week ago, St John North Otago territory manager, Ken Barton, said. ''Desirably, we still need another five to run a [training] course,'' he said.
Volunteers would work 12 hours a week. On call by pager, they did not have to be at the station but could be at home or work.
While there had been seven volunteers, Mr Barton said St John would still be struggling to maintain the 24-hour service without putting pressure on staff.
The service covers an area, depending on availability, from the Lindis Pass to halfway between Twizel and Tekapo and down the Waitaki Valley to halfway between Twizel and Kurow.
Kurow and Tekapo have their own ambulance stations.
Twizel relied on volunteers to provide an emergency ambulance service, preferably one responding from Twizel within 12 minutes. It could take an hour or more for ambulances to come from other areas.
