Great Rescue Operations Quiz

Answer: Fénix (Phoenix). Designed with help from Chilean navy engineers and NASA, this narrow steel cage went down a borehole about 60 cm wide to nearly 700 m deep. Each ascent took about fifteen minutes. The rescue, watched live by more than a billion people, lasted nearly 24 hours.

Answer: It was broadcast live on television for more than two days. The 18-month-old was stuck for about 58 hours some 7 m down. Then-new 24-hour news channels followed every step. The photo of her rescue won its photographer a Pulitzer Prize. Jessica McClure grew up without serious after-effects, apart from scars.

Answer: To be able to hold a companion who falls into a crevasse hidden by a snow bridge. On a glacier, snow can hide deep crevasses covered by a fragile 'snow bridge'. Roped up and well spaced out, the party can stop a fall by throwing themselves down and driving in their ice axes, before setting up a pulley system.

Answer: It detects the heat of the face and head, which contrasts with the cold water. To the naked eye, a head in the waves is almost invisible at night, even a few dozen metres away. The infrared camera reveals temperature differences. Helicopters, aircraft and lifeboats are now equipped with them, as are many search drones.

Answer: Its 25,000 volts can electrocute from a distance, even without touching the wire. On high-speed lines the voltage is so high that an electric arc can form if you get too close, with a ladder for example. Rescuers wait for confirmation that the power is off and the line earthed. Other trains on nearby tracks must also be stopped.

Answer: To find the way out even if visibility drops to zero. In cave diving you can't swim straight up to the surface: you must come back the way you went in. A single fin kick can stir up silt and reduce visibility to nothing in seconds. The line, held in the hand, then guides the diver, as in the myth of Theseus.

Answer: For its experience of long-term isolation: astronauts' nutrition, health and morale. The space agency's doctors, psychologists and engineers advised rescuers on gradual refeeding, organising underground life and designing the capsule. The miners even had a timetable, lighting that simulated day and night, and regular contact with their families.

Answer: A pulley system that multiplies pulling force. One person cannot pull up the weight of a dangling climber by arm strength, let alone with the rope rubbing on the crevasse lip. A pulley system with pulleys and rope clamps divides the effort by three or more. It is taught on mountaineering courses.

Answer: The Fastnet Race, between England and Ireland. An unexpectedly violent depression struck more than 300 yachts. Helicopters, lifeboats and naval ships picked up dozens of crew; 19 people died. The tragedy led to sweeping reforms of offshore racing safety and boat equipment.

Answer: Los Topos, 'the moles'. Faced with massive destruction, volunteers crawled into the ruins to look for survivors, often with bare hands. They then formed an organisation that has helped in rescues in Haiti, Turkey, Nepal and Morocco. Their mole-decorated helmet has become famous.

Answer: About a hundred passengers were stranded, some overnight, then evacuated by helicopter and by rope. Cables crossed and stopped the small cabins hanging above the Vallée Blanche at more than 3,000 m. Helicopter-winched rescuers and guides evacuated passengers cabin by cabin; those left overnight received blankets and food. Everyone was saved.