The misuse of RMS Titanic as a benchmark for ship size
Paul Stott 6th February 2014 Benchmarks in popular reporting of Science
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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:
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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.
114,147 Gross Tons 46,320 Gross Tons 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 was fuelled by coal……. 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
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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?
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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?
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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?
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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?
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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..
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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
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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:
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45 2.5 x larger than the typical
Thousands 40 transatlantic liner of the day
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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
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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
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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. 1 Tun - Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
Titanic was of a similar size to a modern North Sea ferry – not much of a paragon of size in the modern era. How does Titanic stack up against the modern fleet
c. 35,000 GT
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The current equivalent of Demodocus is possibly a handysize or handymax bulk carrier.
This is the most numerous sector of the commercial fleet and could be thought of as a “transit van” of the shipping world. How does Titanic stack up against the modern fleet
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0 Demodocus Titanic Handymax Panamax
Titanic was about 1/3 larger than a handymax and a similar size to a modern panamax….. How does Titanic stack up against the modern fleet
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0 Demodocus Titanic Handymax Panamax Capesize VLBC Titanic was only 50% of the size of a modern capesize bulk carrier (the shipping equivalent of a bulk lorry on the roads), the main long haul vessel for coal and iron ore. Titanic was only 20% of the size of the largest bulk carriers shipping coal and ore to China How does Titanic stack up against the modern fleet
The identification of the largest vessel afloat is debateable -
Maersk McKinney Moller, 18,000 TEU, EEE, is 12% smaller than Oasis of the Seas in terms of GT, but that doesn’t include the boxes on deck.
1 Tun With deck cargo the EEE could be over 250,000 GT, carrying the equivalent of 1.3 Titanics on deck! How does Titanic stack up against the modern fleet
The largest ship ever was the ULCC Belamya, delivered in 1976, which was 275,268 GT.
This is due to be exceeded by a gas processing plant under construction at Samsung, due for delivery in 2016, which will be 300,000 GT.
1 Tun How does Titanic stack up against the modern fleet
Titanic compared to the largest ships in the modern era:
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GT 150
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- Titanic Bellamya Oasis of the Seas Samsung 2030 Use of RMS Titanic as a benchmark
Titanic has no validity as a benchmark to convey ship size in the modern era :
1. It’s reputation for size is only incidental to its fame for other reasons; 2. It’s size was well superseded almost 80 years ago; 3. It would not have been a large vessel in the modern era; 4. It provides no tangible basis to give an impression of size – no-one living has ever seen Titanic – its use as a benchmark is therefore meaningless as well as arbitrary.
1 Tun This leaves us with a need to find a benchmark that can convey ship size to a lay audience: Benchmarks for ship size
Titanic has no validity as a benchmark to convey ship size in the modern era :
What parameter could be used to properly convey the magnitude of the task that salvors were undertaking in trying to right the Costa Concordia?
It has to be on a similarly immediate basis to the use of Porsche to convey the magnitude of an F1 engine power.
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≡ Benchmarks for ship size
The problem lies in the fact that GT is a volumetric measurement and the comparator therefore has to be volumetric.
It is tempting to suggest a linear measure could be used and this would be more accessible to the audience – length and weight are the most obvious candidates.
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10,000 male African elephants
The length parameter does not convey the size of the vessel adequately 10,000 elephants is better in this context but appears a little arbitrary and out of scale. Benchmarks for ship size
The real problem with linear measurements is that they are not consistent in terms of benchmarks between ship types.
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- Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
Comparing length would suggest that and Costa Concordia is only about 8% larger than Titanic – because of the very different block coefficients of the two ships (c.66% for Titanic and c.76% for Costa Concordia) Benchmarks for ship size
The real problem with linear measurements is that they are not consistent in terms of benchmarks between ship types.
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- Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
Comparing weight would seem to provide an obvious answer giving a direct indication of the size of a ship to which we can relate. But there are two problems… Problems with using weight
1. Problem # 1 is that weight is not a commonly reported parameter, so is difficult to find. 2. Problem # 2 is that where weight can be found it is normally displacement, not lightweight, and this leads to inconsistencies between ship types.
1 Tun Benchmarks for ship size
The real problem with linear measurements is that they are not consistent in terms of benchmarks between ship types.
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Thousands 200
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- Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
Comparing weight would suggest that Titanic and Costa Concordia are about the same size Benchmarks for ship size
The real problem with linear measurements is that they are not consistent in terms of benchmarks between ship types.
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GT 150
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- Titanic Bellamya Oasis of the Seas Samsung 2030 Comparing light weight would suggest that Oasis of the Seas is about double the size of Bellamya
Comparing displacement would suggest that Oasis of the Seas is only about 20% of the size of Bellamya Benchmarks for ship size
The benchmark has to be volumetric to be consistent with GT.
It has to be capable of assimilation by the lay reader/viewer to give an impression of volumetric size. The most commonly used parameter for volumetric comparison is the “olympic-sized swimming pool”.
Unfortunately this is too 1small Tun for use with ships, at only around 900 GT.
Costa Concordia is equivalent to 126 swimming pools is as arbitrary as using elephants to compare the weight. Benchmarks for ship size
The ideal comparator would be:
• Between about 30,000 and 100,000 GT • Between about 85,000 and 283,000 cubic metres • Between about 3 million and 10 million cubic feet
This means that the most likely candidates are buildings.
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The problem is that building volumes are rarely quoted – architects deal in linear dimensions and floor area.
This just means that comparators are difficult to find – there isn’t much of an alternative given the requirements for scale above. Benchmarks for ship size
The first attempt was sports stadia – but they tend to be too large.
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Wembley stadium = 400,000 GT MCG = 600,000 GT*
Stating that Costa Concordia is around ¼ the size of Wembley stadium loses any impact
* Moulded volume Benchmarks for ship size
Large religious buildings provide potential but reliable volumes have not been found.
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St Peter’s Basilica = 424,000 GT Saint Paul’s = 55,000 GT (un-verified) Benchmarks for ship size
Stating that the Costa Concordia is equivalent in size to almost 2 St. Paul’s puts into perspective the size of the job that the salvors were trying to achieve in parbuckling the ship!
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= + Benchmarks for ship size
The next large spaces tried were concert venues.
Happily there is a credible source for auditorium volumes:
Beranek’s book lists the acoustical properties of the world’s major concert venues, including the internal volume of auditoria.
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Leo Beranek, acoustic engineer, USA, b. 1914 Benchmarks for ship size
The next large spaces tried were concert venues.
Some are too large:
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Millennium dome – 850,000 GT Benchmarks for ship size
The next large spaces tried were concert venues.
Most, even the large ones, are unfortunately too small:
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La Scala, Milan – 4,000 GT Carnegie Hall, New York – 8,600 GT Benchmarks for ship size
The next large spaces tried were concert venues.
Only two well known spaces fall within the required size bracket:
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Royal Albert Hall, London – 30,000 GT Great Hall of the People, Beijing– 32,000 GT 人民大会堂 Benchmarks for ship size
The next large spaces tried were concert venues.
Stating that the Costa Concordia is equivalent in size to almost 4 Albert Halls or 4 人民大会堂 puts into perspective the size of the job that the salvors were trying to achieve in parbuckling the ship!
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= Benchmarks for ship size
The next large spaces tried were concert venues.
Stating that the Costa Concordia is equivalent in size to almost 4 Albert Halls or 4 人民大会堂 puts into perspective the size of the job that the salvors were trying to achieve in parbuckling the ship!
But only if these benchmarks mean anything to the audience.
1 Tun To be effective, the benchmark needs to be localised within the experience of the intended audience. Benchmarks for ship size
Finally, an iconic building was sought in London that might be useable.
Norman Foster’s “Swiss Re Headquarters”, affectionately known as the “Gherkin”.
Appropriate for marine use as it was built on the ruins of the Baltic Exchange at St Mary Axe, following the detonation of a 1 tonne bomb on 10th April 1992. 1 Tun It is also mercifully regular, having a circular cross section for its full height, enabling volume to be calculated by Simpson’s rules, based on a sectional drawing. Benchmarks for ship size
Finally, an iconic building was sought in London that might be useable.
Norman Foster’s “Swiss Re Headquarters”, affectionately known as the “Gherkin”.
128,500 GT.
1 Tun Benchmarks for ship size
Finally, an iconic building was sought in London that might be useable.
Stating that the salvors of the Costa Concordia are attempting to man-handle an object the size of a sky scraper, London and the UK’s third tallest building, really puts into perspective what they achieved that day.
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= Benchmarks for ship size
Finally, an iconic building was sought in London that might be useable.
Stating that the salvors of the Costa Concordia are attempting to man-handle an object the size of a sky scraper, London and the UK’s third tallest building, really puts into perspective what they achieved that day.
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But only if you know what the ‘Gherkin’ is!
Adding that it weighs 55,000 tonnes is also helpful – if you can find a lightship value. Benchmarks for ship size
I stopped there, because I had work to do!
Other localised benchmarks are needed:
• Burj Al Arab, Dubai? • PSA building, Singapore? • Australia Square Building, Sydney? • HSBC Building, Hong Kong?
When you have an idle moment, please 1 Tun consider adding to the list.
Benchmarks for ship size
Ship size ready reckoner:
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