Human ingenuity is incredible. Love it. For thousands of years, people have made cranes that could lift enormous weights, way beyond what we could lift unaided. Physics and math extend the power of human mind and muscle.
In “The sky is the limit: human powered cranes and lifting devices,” Kris De Decker writes:
The most common tower crane used in construction today has a lifting capacity of some 12 to 20 tonnes. For quite a few construction projects in ancient history, this type of crane would be completely inadequate.
The majority of stones that make up the almost 140 discovered Egyptian pyramids have a weight of “only” 2 to 3 tonnes each, but all of these structures (built between 2750 and 1500 BC) also hold stone blocks weighing 50 tonnes, sometimes more. The temple of Amon-Ra at Karnak contains a labyrinth of 134 columns, standing 23 metres (75 feet) tall and supporting crossbeams weighing 60 to 70 tonnes each. The 18 capital blocks of Trajan’s column in Rome weigh more than 53 tonnes and they were lifted to a height of 34 metres (111 feet). The Roman Jupiter temple in Baalbek contains stone blocks weighing over 100 tonnes, raised to a height of 19 metres (62 feet).
The job [of moving the Vatican obelisk] was done using a wooden construction 27.3 metres tall, ropes up to 220 metres long, 40 capstans, 800 men and 140 horses (when lowering the obelisk the workforce consisted of 907 men and 75 horses). While the whole undertaking took more than a year – including the transport of the obelisk (on rollers) and the assembly of the tower, the capstans and other lifting machinery – the stone was erected in just 13 hours and 52 minutes. As a result of this successful operation, many more obelisks were moved around Rome, one of these weighing 510 tonnes.…
[A] 60 ton crane was built for the new docks at Keyham, which could lift loads five times heavier up to heights of 60 feet (18 metres) and over a circle 104 feet (32 metres) in diameter.
It is this “colossal crane,” probably the most powerful hand driven crane ever built, that is described in detail by Fairbairn:
A mechanical advantage of 632 to 1 means that each of the four men had to apply a force of only 23.7 kilograms in order to lift a weight of 60 tonnes – and this while operating a winch instead of a more efficient treadwheel.