This week in 1960

52 years ago, on 23 January 1960, humans went deeper than ever before – and indeed since. The Trieste bathyscaphe submersible touched down at 10,914m below sea level near the bottom of the Challenger Deep section of the Mariana Trench in the Pacific Ocean.

Discussing the accomplishment in its yearly technology round-up of 1960, The Engineer said: ’Penetration into stranger and more forbidding environments has been an exciting adjunct of technical advance throughout the ages.’

The design was actually penned 25 years prior to the achievement by Prof August Piccard, whose son Jacques went on to pilot the craft alongside Don Walsh of the US Navy.

’It has a compartmented hull filled with 125m3 of petrol, from which is slung a 12-ton steel sphere, 2.18m in diameter and with 120mm-thick walls. Buoyancy is increased by jettisoning steel shot and decreased by releasing petrol. The petrol communicates with the sea so that there is no resultant pressure on the hull, while the steel sphere can resist nearly 2,200 atmospheres, as shown by tests on a 1:20 scale model which was crushed at that pressure.