How a Ship-to-Shore Crane Stops a Swinging Box

A ship-to-shore crane has to land a swinging container within a few millimetres, yet nothing on the crane ever grabs the box. Here is how a container crane really stops the swing: rope length, a trolley move timed to half a swing, a camera in the loop, and the one force no anti-sway system can beat. Chapters: 0:00 Nothing grabs the box 1:06 Four parts 2:09 The one number 3:30 Half speed, half a swing 4:58 The camera in the loop 6:47 The wind limit 8:26 What to remember Sources: Siemens, SIMOCRANE Sway Control (brochure): https://assets.new.siemens.com/siemens/ass... Siemens, SIMOCRANE Sway Control System for STS Crane: https://assets.new.siemens.com/siemens/ass... Liebherr, Ship-to-shore gantry crane, technical data sheet (2026 v2): https://www-assets.liebherr.com/media/bu-m... ZPMC, quay cranes for Piraeus Container Terminal (240 m/min trolley, anti-sway system): https://www.zpmc.com/content/676c11ba00256... ; also Port Technology International: https://www.porttechnology.org/zpmc-delive... Liebherr, Technical Description: Ship to Shore Gantry Cranes (design wind speeds; anti-sway hoist rope reeving): https://www.liebherr.com/shared/media/mari... Tim Watson, "Anti-sway systems", Hoist magazine (2004): https://www.hoistmagazine.com/analysis/ant... (same text: "Swing low", Cranes Today, 2005: https://www.cranestodaymagazine.com/analys...) HyperPhysics (Georgia State University), Simple Pendulum: http://hyperphysics.phy-astr.gsu.edu/hbase... Vision Systems Design, "Antisway crane system embeds smart camera" (MVLZ / Matrox): https://www.vision-systems.com/home/articl... ; specs (3–50 m, 10 mm, 20 Hz): Wiley Industry News, "All good things come from above": https://wileyindustrynews.com/en/contribut... O. J. M. Smith, "Posicast Control of Damped Oscillatory Systems", Proceedings of the IRE, 1957: https://doi.org/10.1109/jrproc.1957.278530 University at Buffalo, Posicast control (origin of the name "positive cast"): https://code.eng.buffalo.edu/tdf/article01... N. C. Singer, W. P. Seering (MIT), "Preshaping Command Inputs to Reduce System Vibration", J. Dyn. Sys., Meas., Control 112(1), 1990: https://doi.org/10.1115/1.2894142 Zaber, "Input Shaping for Vibration Reduction" (ZV shaper, half-period penalty): https://www.zaber.com/articles/input-shapi... TT Club, "TT Talk – Mitigating the impact of windstorms in container terminals" (2020): https://www.ttclub.com/news-and-resources/... Autoridad del Canal de Panamá, water-saving basins: https://pancanal.com/en/first-panama-canal... Stock footage: Pexels and Pixabay contributors (Pexels / Pixabay licenses). Photos (Wikimedia Commons, CC BY-SA 4.0, https://creativecommons.org/licenses/by-sa... Panama Canal, Agua Clara locks.jpg: Dr. Thomas Liptak, CC BY-SA 4.0, https://commons.wikimedia.org/wiki/File:Pa... All footage is real (stock and archive); diagrams are rendered for this episode. Music: original instrumental generated with ElevenLabs Music. Ambient sound: one ElevenLabs Sound Effects machine-hum loop plus synthesized wind, sea and air noise.