A caver, who has suffered multiple injuries after a fall, is trapped approximately 300 metres deep in the Ellis Basin cave system on Mount Arthur. A full-scale cave search and rescue is launched, with cave teams tasked to locate the injured man, stabilise and safely transport him in a stretcher to the surface.
This was the scenario used in New Zealand’s largest cave search and rescue training exercise (SAREX) to date, which took place from 26 February – 3 March 2019. The event attracted over 100 cavers from New Zealand and Australia as well as Police and LandSAR teams. It was the ninth event of its kind – funded every three years by New Zealand Search and Rescue to test cave rescue capability.
On 26 February, an advance team began pre-rigging the search area in the cave and fixing ropes, to simulate those left by the missing party. This set the scene for a small group of experienced cavers to weave their way down eight pitches underground, where they waited to be rescued.
Sergeant Malcolm York, head of Tasman Police Search and Rescue and Incident Controller for the cave SAREX said the cavers arrived at different times from different regions.
“Reid Helicopters flew everyone up to the area – cave rescuers, surface support personnel and tonnes of gear. This in itself was a logistical challenge, so ensuring we had the right people as air controllers was crucial.”
Before the flying in was completed, a ‘hasty’ team was deployed into the cave to conduct an initial search. The missing party was found around four hours later and a medical team dispatched to assist. What followed was approximately 48 hours of highly skilled team work, taken in shifts, to evacuate the patient and all caving personnel without incident.
Cave Search and Rescue Adviser John Patterson said the exercise provided all parties with the opportunity to collaboratively test their knowledge, skills and equipment. For example, the latest communication technology – the cave-link radio communication system (which transmits text messages through rock) – was tested at depth, with successful results.
“One radio unit was left at the surface with the entrance team and another was sent to the minus 300m level. The third unit went with the search team to find the missing party.”
“Once the search team had located the injured caver, they were able to use the radio’s text system to send very precise information about his location, the nature of his injuries and the type of assistance required. These messages were transmitted up to the entrance team within 4 hours of entering the cave.”
By comparison, another communications team used a more traditional Michie phone – which operates via a single telephone wire run through the cave off reels – and this took about 16 hours to reach the accident site.
“From a search and rescue perspective, the sooner you get that information back to the surface, the sooner you can escalate the rescue or stand people down,” said John.
Cave rescue teams were also able to trial new, lightweight hauling techniques using 10mm ropes instead of the 11mm used in previous years.
“These thinner ropes are more technically suited to cave rescue as opposed to cliff or alpine rescue,” said John. “The weight and bulk difference between a 10 and 11mm rope is significant. On a rescue, we install a lot more safety lines in the cave than those used on a recreational cave trip – over 2km of rope was used in this exercise. A 10mm rope is more than adequate strength-wise.”
Counterbalance weight techniques, using smaller teams, proved to be the most efficient way to get the stretcher up the eight pitches to the surface.
“With less people on the end of the rope, you apply less force on the anchors,” said John.“It’s quick and reduces the risk to all concerned. Less time spent on the pitch means less chance of rockfall.”
Malcolm said Police depend very heavily on the technical expertise of cavers to respond to underground incidents.
“There are no other search and rescue conditions that are more challenging,” he said. “When you are negotiating complex cave passages to reach people in complete darkness, it is super important to know we are on a good footing with cave search and rescue specialists.”
“We have about one or two caving incidents each year and we need to be prepared. Building on our experience and working on relationships makes us so much more efficient.”
The patient emerged at about 6pm on Saturday 2 March, approximately 6 hours ahead of the expected schedule. Helicopters arrived the following day to transport the cavers back to civilisation.
“It was a really good result,” said Malcolm. “It couldn’t have gone any better.”
For more information, go to www.nzsar.govt.nz