Gross Tonnage DECODED: Finally Understand Cruise Ship Size

Unlock the Mystery of Cruise Ship Size! Ever wondered how those colossal cruise ships are measured? In this video, we decode the often-confusing concept of "Gross Tonnage" (GT) and explain why it's the key to understanding the true size of these floating cities. Forget what you think you know about ship weight – we break down the crucial differences between Gross Tonnage, Gross Registered Tonnage (GRT), Net Tonnage, and even Displacement. Join us as we journey through the fascinating world of maritime measurement, starting with the sheer scale of the World's Largest Cruise Ship (0:00) before diving into the definition of ship "tonnage" (0:49) and precisely what Gross Tonnage means (1:22). We'll clarify the historical distinction between GT and GRT (1:56), tackle the question of a cruise ship's actual weight (3:26), and explain Displacement (3:50) and Net Tonnage (4:00). Finally, we'll even take a quick look at the tonnage comparison between the Icon of the Seas and the Queen Mary 2 (4:25) before wrapping up with the key tonnage takeaways you need to know (4:29). Want to explore more maritime history and cruising insights? Check out my links below! 🚢 My History Website: https://www.chriscunard.com/ 📚 Buy my books: https://www.chrisframe.com.au/books 👕 Buy cruise merch: https://chrisframeofficial.Teemill.com/ 🎶 Listen to The Big Cruise Podcast: https://thebigcruisepodcast.com/ 🛳️ Learn more about cruising at my Blog: https://www.chrisframe.com.au/ About this video: As a measurement, gross tonnage has been the standard since 1969, when the International Convention on Tonnage Measurement of Ships was taken up by the International Maritime Organisation. The convention came into complete effect in 1982, and since then all passenger ship tonnage, regardless of the age of the ship, has been measured in gross tonnage. The calculation to work out gross tonnage is a bit mind bending and as I am not a mathematician I won’t try and explain all the calculations. However, for the purposes of this video what you need to know is gross tonnage is calculated by a logarithmic relationship between the ship’s total volume in cubic metres - V, and a multiplier, K. I’ve put the calculation up on the screen for those of you who are interested. The implementation of a gross ton was a significant step forward to standardise the measurement of a ship’s size across national borders. Prior to this, there were numerous national standards but no true international agreement. Gross Registered Tonnage or GRT was one of the most common older measurements you may have heard of. It is the measure you’ll hear used for historic ships like Titanic, and it is often mixed up with gross tonnage. GRT was devised by the Moorsom Commission all the way back in 1849. The measure, of British origin calculated the size of a ship by the total internal volume. Like gross tonnage that succeeded it, GRT was an internal volume measure. However here the volume used in the calculation was based on the British imperial system. -- Imagery References: Icon of the Seas: Royal Caribbean - https://www.royalcaribbeanpresscenter.com/images/ including the Jan 2024 Thumbnail. Andrew Sassoli-Walker - https://www.solentphotographer.com/ Henderson & Cremer Collection. Licenses: Wonder of the Seas: CC BY SA 4.0 Jörg Fuhrmann - https://commons.wikimedia.org/wiki/File:Wonder_of_the_Seas.jpg Wind Surf: CC BY SA 2.0 Kees Torn - https://commons.wikimedia.org/wiki/File:Wind_Surf_(ship,_1989)_001.jpg Titanic Images - All Public Domain USA / UK. Levithan Image - Library of Congress, Public Domain (USA): https://commons.wikimedia.org/wiki/File:SS_Leviathan.jpg Empress of Britain and Olympic - Public Domain: https://commons.wikimedia.org/wiki/File:RMS_Empress_of_Britain_entering_dry_dock.jpg Titanic (Thumbnail): CC.0 Public Domain: https://commons.wikimedia.org/wiki/File:Titanic-Cobh-Harbour-1912.JPG Pexels Imagery: Video by Jean Pablo Silva from Pexels: https://www.pexels.com/video/aerial-view-of-a-cruise-ship-at-the-port-in-puerto-rico-15366340/ Video by Pixabay from Pexels: https://www.pexels.com/video/aerial-shot-of-cruise-ship-854976/ Thumbnail 2024 created with support from Bing AI / Copilot Designer: Adobe Stock: August 2023 thumbnail Royalty Free Standard License. Royal Caribbean: Inage of Utopia of the Seas Cunard: Thumbnail of QE2 in 1995 entering Sydney (2025 Thumbnail) Tags: #cruisenews #iconoftheseas #cruiseship #cruiseline #royalcaribbean #utopiaoftheseas #ididntknow #didyouknow #facts #interestingfacts #rci #oceanliner #cruiseship #cruiseships #cruisenewsupdate #oceanlinerdesigns #titanic