The misuse of RMS Titanic as a benchmark for ship size Paul Stott 6th February 2014 Benchmarks in popular reporting of Science ≡ 11 elephants Popular reporting often makes use of tangible common objects to convey size This is relatively easy with linear or square dimensions and weight Benchmarks in popular reporting of Science For ships the default is often to compare the ship to RMS Titanic to try to convey a sense of a vessel’s size: BBC Radio 4, Today Programme, 16th Sept 2013: “Costa Concordia weighs twice as much as the Titanic” BBC Newsround, 16th Septeber 2013: “Costa Concordia weighs twice as much as the Titanic” ExtremeTech.com: “Costa Concordia: How a ship twice the size of Titanic is being lifted from the seabed” Use of RMS Titanic as a benchmark The intent of this comparison is laudable: it is to convey the heroic nature of the salvors in man-handling something that is very large. So, where is the problem? ≡ 2x Use of RMS Titanic as a benchmark Problem number 1: The common misinterpretation of the meaning of Gross Tonnage as a measure of weight. BBC Radio 4, Today Programme, 16th Sept 2013: “Costa Concordia weighs twice as much as the Titanic” BBC Newsround, 16th Septeber 2013: “Costa Concordia weighs twice as much as the Titanic” 114,147 Gross Tons 46,320 Gross Tons Use of RMS Titanic as a benchmark Problem number 1: The common misinterpretation of the meaning of Gross Tonnage as a measure of weight. In terms of tonnage, Costa Concordia is 2.5 times the size of Titanic, so the BBC’s statement appears approximately correct….. except that tonnage is a measure of volume, not weight: 1 Tun 114,147 Gross Tons 46,320 Gross Tons Use of RMS Titanic as a benchmark Problem number 1: The common misinterpretation of the meaning of Gross Tonnage as a measure of weight. In terms of tonnage, Costa Concordia is 2.5 times the size of Titanic, so the BBC’s statement appears approximately correct….. except that tonnage is a measure of volume, not weight: 1 Tun Tonnage was introduced as a means of taxing ships according to their earning power, determined by their carrying capacity. Use of RMS Titanic as a benchmark Problem number 1: The common misinterpretation of the meaning of Gross Tonnage as a measure of weight. 1 Tun 55,000 tonnese 52,310 tonnes Full load displacement When looked at correctly the two vessels weigh a remarkably similar amount: Titanic was built with much heavier scantlings, was joined by millions of rivets and was114,147 fuelled Gross by Tons coal……. 46,320 Gross Tons Use of RMS Titanic as a benchmark Problem number 2: does Edwardian engineering have any relevance as a benchmark in the modern context? 190 bhp 1 Tun Fiat S74 – the leading Grand Prix car of 1912, the year of Titanic’s delivery from Harland and Wolff Can this car be used as a benchmark to convey the power of a modern F1 car in any meaningful way? Use of RMS Titanic as a benchmark Problem number 2: does Edwardian engineering have any relevance as a benchmark in the modern context? ≡ 1 Tun Stating that the F1 car has engine power equivalent to 5 Fiat S74 gives no immediate tangible impression of how powerful a modern F1 car is. The comparison conveys how relatively weak the 1912 car was, rather than giving a sense of the power of an F1 car. Use of RMS Titanic as a benchmark Problem number 2: does Edwardian engineering have any relevance as a benchmark in the modern context? ≡ 1 Tun Fiat S74 – the leading Grand Prix car of 1912, the year of Titanic’s delivery from Harland and Wolff, is equivalent in engine power to a modern family car. Use of RMS Titanic as a benchmark Problem number 2: does Edwardian engineering have any relevance as a benchmark in the modern context? ≡ 1 Tun Stating that the F1 car has engine power equivalent to three Porsche 911s (and weighs about the same as a large paper clip) gives the reader a direct impression of how powerful the car is. The Porsche provides a tangible benchmark that can be directly related to. Use of RMS Titanic as a benchmark Problem number 2: does Edwardian engineering have any relevance as a benchmark in the modern context? 1 Tun The Edwardian products provide no tangible benchmark with which we can intuitively gauge the size of a modern product. Has the size of the Titanic any relevance in the modern context? Was it a large ship? Was Titanic a Large ship? Titanic’s legendary status is based on a combination of a number of factors: 1. The unprecedented level of opulence: a first class ticket to New York cost the equivalent of £64,000 in today’s money. 2. The irony of the label ‘unsinkable’ that was attached to the ship. 3. The extent of the tragedy: the loss of 1,517 souls remains the 6th worst peacetime loss of life at sea. 4. The catastrophic inadequacy of LSA regulations. 5. The moral bankruptcy in the correlation between wealth and chances of survival. 6. The ship’s size. 1 Tun Without factors 1 to 5, Titanic would no longer be remembered as a paragon of size. By 1936 the Titanic’s size had been exceeded by a factor of 2 (RMS Queen Mary) and the Titanic has no more relevance than the Fiat S74 in the modern era If the vessel were remembered specifically for size then the paragon would be Olympic, the first of class that preceded Titanic. Benchmarks in popular reporting of Science Stating that the Costa Concordia is 40% larger than the RMS Queen Mary or “twice” the size of the RMS Olympic or RMS Brittanic is clearly meaningless and no-one would suggest these vessels as size comparators in the modern context.. But it is the same thing as using Titanic as the comparator. ? 2x Was Titanic a Large ship? But this does not mean to say that the Titanic may not be a good benchmark for large ship size. To judge whether Titanic was a large ship in her day we could use the same benchmarking technique and compare the ship to other famous vessels. Arguably, the most famous ship prior to Titanic in public consciousness may have been Cutty Sark.. 1 Tun 1869 963 GT Was Titanic a Large ship? Size of circles is proportional to gross tonnage: 1 Comparison with Cutty Sark (1869) Titanic was 50 times larger 0.5 Perhaps not a fair1 Tuncomparison as Cutty Sark is remembered primarily for speed and good 0 looks 1860 1870 1880 1890 1900 1910 1920 Year of delivery Was Titanic a Large ship? Rather than Cutty Sark, the prior paragon of size was probably Brunel’s nemesis, the Great Eastern Great Eastern was 1858 6 times larger than 18,915 GT any preceding ship and it would be 40 years before anyone tried to build anything that 1 Tun large again. The ship was sadly a technical failure. Was Titanic a Large ship? Size of circles is proportional to gross tonnage: 1 Comparison with Great Eastern (1858) Titanic is 2.5 times larger 0.5 1 Tun 0 1840 1850 1860 1870 1880 1890 1900 1910 1920 1930 Year of delivery Was Titanic a Large ship? Other relevant ships of the Edwardian era: Typical transatlantic liner: RMS Oceanic, 1899, 17,274 GT Typical cargo liner: SS Demodocus, 1912, 6,689 GT 1 Tun Superseded record holder for size: Mauretania, 1907, 31,938 GT Was Titanic a Large ship? Titanic was: 50 45 2.5 x larger than the typical Thousands 40 transatlantic liner of the day 35 30 45% larger than the previous GT 25 record holder, built only 4 20 years previously 15 10 7 x larger than the1 typicalTun 5 cargo liner of the day 0 Demodocus Oceanic Mauretania Titanic By any measure at the time, therefore, Titanic earned the epithet “Leviathan” The magnitude of Brunel’s challenge A digression: The Titanic is remembered in popular consciousness as an epitome of a large vessel. But look at what Brunel achieved… SS Great Britain 1843, 3,270 GT 1 Tun The world’s first recognisably ‘modern’ ship: Ocean-going, screw powered, 12 knots, made of metal The magnitude of Brunel’s challenge Size of circles is proportional to gross tonnage: 1 0.5 1 Tun 0 1820 1840 1860 1880 1900 1920 1940 Year of delivery No wonder it killed him! Was Titanic a Large ship? RMS Queen Mary 90 1936 80 81,237 GT Thousands 70 60 50 GT 40 30 20 1 Tun 10 0 Demodocus Oceanic Mauretania Titanic Queen Mary By any measure at the time, therefore, Titanic earned the epithet “Leviathan” But by 1936 Titanic had been succeeded by a factor of almost 2x. How does Titanic stack up against the modern fleet Having concluded that Titanic was a “leviathan” in the Edwardian era, does this have any currency as a benchmark for the modern fleet. How big is a modern large ship? Costa Concordia, 2004, 114,147 GT 1 Tun Queen Mary 2, 2003, 148,528 GT Oasis of the Seas, 2009, 222,282 GT – the largest vessel afloat in 2013 How does Titanic stack up against the modern fleet 250 The largest ship in service is Thousands 200 currently almost 5 times larger than Titanic. 150 GT Titanic is not a small ship in 100 the modern era (as Demodocus would be) but is 50 no more than mid-sized.