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Tunneling speeds increase over time. The first TBM peaked at 4 meters per week. This increased to 16 meters per week four decades later. By the end of the 19th century, speeds had reached over 30 meters per week. 21st century rock TBMs can excavate over 700 meters per week, while soil tunneling machines can exceed 200 meters per week.
Freighter Fairpartner carrying the disassembled tunnel boring machine into the Port of Seattle in April 2013. Bertha was designed and manufactured by Hitachi Zosen Sakai Works of Osaka, Japan, and was the world's largest earth pressure balance tunnel boring machine, [14] at a cutterhead diameter of 57.5 feet (17.5 m) across.
13 December 2024: World Championships: Budapest, Hungary [79] 200m individual medley: 2:04.00 Sydney Pickrem: London Roar 21 November 2020: International Swimming League: Budapest, Hungary [80] 400m individual medley: 4:15.48 WR: Summer McIntosh Canada 14 December 2024: World Championships: Budapest, Hungary [81] 4×50m freestyle relay: 1:35.00
As of January 2013, CMAS recognises world and other records for the following techniques and distances for both males and females in the age groups of Senior (i.e. 18 years and older) and Junior (i.e. 12 to 17 years old) where these are made in an Olympic-size swimming pool (i.e. 50m length) and are measured by electronic automatic officiating equipment:
[13] 50m butterfly: 22.75 Ben Proud Great Britain 24 July 2017: World Championships: Budapest, Hungary [14] 100m butterfly: 50.67 sf: James Guy Great Britain 28 July 2017: World Championships: Budapest, Hungary [15] 200m butterfly: 1:54.58 sf: Michael Rock Great Britain 28 July 2009: World Championships: Rome, Italy [16] 200m individual medley ...
the swimming events of the World Aquatics Championships, held in a long course (50 meter) pool. World Aquatics Swimming Championships (25m), at which swimming is the only discipline. This meet is held in a short course (25 meter) pool. Both events are organized by the international governing body for aquatics, World Aquatics (formerly known as ...
Humanity has thrown the global water cycle off balance “for the first time in human history,” fueling a growing water disaster that will wreak havoc on ... (just over 1,000 gallons) a day to ...
Tunnel Construction. Tunnels are dug in types of materials varying from soft clay to hard rock. The method of tunnel construction depends on such factors as the ground conditions, the ground water conditions, the length and diameter of the tunnel drive, the depth of the tunnel, the logistics of supporting the tunnel excavation, the final use and shape of the tunnel and appropriate risk management.