Craig Cwm Silyn. Photo: David Medcalf CC-BY-SA-2.0

Two climbers stuck on a crag were rescued in a nine-hour operation involving two mountain rescue teams and an RAF search and rescue helicopter crew.

The man and woman, students from the Manchester area, called for help after getting cragfast on Craig yr Ogof on the Nantlle Ridge in the West of the Snowdonia national park at 9.10pm last night.

Aberglaslyn and Llanberis Mountain Rescue Teams went to the aid of the climbers on Craig Cwm Silyn and a Sea King helicopter from RAF Valley attempted to winch the pair off the crag, but were defeated by high winds and lowering cloud.

A spokesperson for the Llanberis team said dry windy conditions gave way to storm-force winds with low cloud and drizzle.

The spokesperson added: “The pair started climbing early in the afternoon when conditions were windy but dry.

“Their progress was very slow, taking six hours to reach half-way. By this time the wind had increased and drizzle was falling making the rock greasy.

“They called 999 reporting themselves cragfast and requiring help. Mild hypothermia was setting in as they were only lightly dressed in summer clothing. They had bitten off more than they could chew on this route.

“The couple attempted to embrace the climbers’ ethic of self-reliance in the mountains by abseiling off the route in retreat, however this put them into steeper ground and they needed help to escape any further.

Thirteen Aberglaslyn and 14 Llanberis volunteer rescuers worked through the night in weather conditions described as atrocious, making their way to the top of the 734m (2,408ft) peak to reach the climbers.

The Llanberis spokesperson said the climbers had appropriate climbing equipment but unsuitable clothing and footwear. “Planning and preparation pays dividends. Experience is required to undertake a climb on a big cliff; route finding can be difficult.

“Spare clothing would have helped considerably.”

The spokesperson added: “Check the weather forecast. Conditions can change considerably over a few hours in the mountains.

“This was a long, difficult and arduous rescue undertaken in darkness and challenging weather conditions.

“However it was an example of excellent joint working between the Aberglaslyn and Llanberis Mountain Rescue Teams and the crew of 22 Rescue Squadron who airlifted team members to the location.”

The rescue ended at 6am today when the rescuers finally managed to reach the pair and bring them to safety.

The climbers were taken to hospital by ambulance for a check-up.