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Paul Stott
6th February 2014
The misuse of RMS Titanic as a benchmark for ship size
Benchmarks in popular reporting of Science
Popular reporting often makes use of tangible common objects to convey size
This is relatively easy with linear or square dimensions and weight
≡ 11 elephants
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”
ExtremeTech.com: “Costa Concordia: How a ship
twice the size of Titanic is being lifted from the seabed”
BBC Newsround, 16th Septeber 2013: “Costa
Concordia weighs twice as much as the Titanic”
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.
46,320 Gross Tons 114,147 Gross Tons
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”
Use of RMS Titanic as a benchmark
Problem number 1: The common misinterpretation of the meaning of Gross
Tonnage as a measure of weight.
46,320 Gross Tons114,147 Gross Tons
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
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 46,320 Gross Tons114,147 Gross Tons
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?
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?
190 bhp
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 Tun
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.
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 Tun
0
0.5
1
1860 1870 1880 1890 1900 1910 1920
Year of delivery
Comparison with Cutty Sark
(1869)
Titanic was 50 times larger
Perhaps not a fair comparison
as Cutty Sark is remembered
primarily for speed and good
looks
Was Titanic a Large ship?
Rather than Cutty Sark, the prior paragon of size was probably Brunel’s nemesis,
the Great Eastern
1 Tun
1858
18,915 GT
Great Eastern was
6 times larger than
any preceding ship
and it would be 40
years before
anyone tried to
build anything that
large again.
The ship was sadly
a technical failure.
Was Titanic a Large ship?
1 Tun
Comparison with Great
Eastern (1858)
Titanic is 2.5 times larger
0
0.5
1
1840 1850 1860 1870 1880 1890 1900 1910 1920 1930
Year of delivery
Size of circles is proportional to gross tonnage:
Was Titanic a Large ship?
Other relevant ships of the Edwardian era:
1 Tun
Typical transatlantic liner:
RMS Oceanic, 1899, 17,274 GT
Typical cargo liner:
SS Demodocus, 1912, 6,689 GT
Superseded record holder for size:
Mauretania, 1907, 31,938 GT
0
5
10
15
20
25
30
35
40
45
50
Demodocus Oceanic Mauretania Titanic
GT
Tho
usa
nd
s
Was Titanic a Large ship?
1 Tun
Titanic was:
2.5 x larger than the typical
transatlantic liner of the day
45% larger than the previous
record holder, built only 4
years previously
7 x larger than the typical
cargo liner of the day
By any measure at the time, therefore, Titanic earned the epithet “Leviathan”
The magnitude of Brunel’s challenge
1 Tun
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
The world’s first recognisably ‘modern’ ship:
Ocean-going, screw powered, 12 knots, made
of metal
0
0.5
1
1820 1840 1860 1880 1900 1920 1940
Year of delivery
The magnitude of Brunel’s challenge
1 Tun
No wonder it killed him!
Size of circles is proportional to gross tonnage:
0
10
20
30
40
50
60
70
80
90
Demodocus Oceanic Mauretania Titanic Queen Mary
GT
Tho
usa
nd
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Was Titanic a Large ship?
1 Tun
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.
RMS Queen Mary
1936
81,237 GT
How does Titanic stack up against the modern fleet
1 Tun
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
Queen Mary 2, 2003, 148,528 GT
Oasis of the Seas, 2009, 222,282 GT – the largest
vessel afloat in 2013
-
50
100
150
200
250
Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
GT
Tho
usa
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How does Titanic stack up against the modern fleet
1 Tun
The largest ship in service is
currently almost 5 times larger
than Titanic.
Titanic is not a small ship in
the modern era (as
Demodocus would be) but is
no more than mid-sized.
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
1 Tun
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.
c. 35,000 GT
How does Titanic stack up against the modern fleet
1 Tun
Titanic was about 1/3 larger than a handymax and a similar size to a modern
panamax…..
0
5
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15
20
25
30
35
40
45
50
Demodocus Titanic Handymax Panamax
GT
Tho
usa
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How does Titanic stack up against the modern fleet
1 Tun
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
0
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Demodocus Titanic Handymax Panamax Capesize VLBC
GT
Tho
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How does Titanic stack up against the modern fleet
1 Tun
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.
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
1 Tun
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.
-
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100
150
200
250
300
Titanic Bellamya Oasis of the Seas Samsung 2030
GT
Tho
usa
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How does Titanic stack up against the modern fleet
1 Tun
Titanic compared to the largest ships in the modern era:
Use of RMS Titanic as a benchmark
1 Tun
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.
This leaves us with a need to find a benchmark that can convey ship size to a
lay audience:
Benchmarks for ship size
1 Tun
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.
≡
Benchmarks for ship size
1 Tun
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.
≡
26 Double decker buses
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
1 Tun
The real problem with linear measurements is that they are not consistent in terms of
benchmarks between ship types.
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)
-
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150
200
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Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
GT
Tho
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Benchmarks for ship size
1 Tun
The real problem with linear measurements is that they are not consistent in terms of
benchmarks between ship types.
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…
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100
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Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
GT
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Problems with using weight
1 Tun
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.
Benchmarks for ship size
1 Tun
The real problem with linear measurements is that they are not consistent in terms of
benchmarks between ship types.
Comparing weight would suggest that Titanic and Costa Concordia are about the
same size
-
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100
150
200
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Titanic Costa Concordia Queen Mary 2 Oasis of the Seas
GT
Tho
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Benchmarks for ship size
1 Tun
The real problem with linear measurements is that they are not consistent in terms of
benchmarks between ship types.
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
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Titanic Bellamya Oasis of the Seas Samsung 2030
GT
Tho
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Benchmarks for ship size
1 Tun
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 small 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
1 Tun
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.
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
1 Tun
The first attempt was sports stadia – but they tend to be too large.
MCG = 600,000 GT* Wembley stadium = 400,000 GT
Stating that Costa Concordia is around ¼ the size of Wembley stadium loses any impact
* Moulded volume
Benchmarks for ship size
1 Tun
Large religious buildings provide potential but reliable volumes have not been found.
St Peter’s Basilica = 424,000 GT Saint Paul’s = 55,000 GT (un-verified)
Benchmarks for ship size
1 Tun
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!
= +
Benchmarks for ship size
1 Tun
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.
Leo Beranek, acoustic engineer, USA, b. 1914
Benchmarks for ship size
1 Tun
The next large spaces tried were concert venues.
Some are too large:
Millennium dome – 850,000 GT
Benchmarks for ship size
1 Tun
The next large spaces tried were concert venues.
Most, even the large ones, are unfortunately too small:
La Scala, Milan – 4,000 GT Carnegie Hall, New York – 8,600 GT
Benchmarks for ship size
1 Tun
The next large spaces tried were concert venues.
Only two well known spaces fall within the required size bracket:
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
1 Tun
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!
=
Benchmarks for ship size
1 Tun
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.
To be effective, the benchmark needs to be localised within the experience of the
intended audience.
Benchmarks for ship size
1 Tun
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.
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
1 Tun
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.
Benchmarks for ship size
1 Tun
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.
Benchmarks for ship size
1 Tun
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.
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
1 Tun
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
consider adding to the list.
Benchmarks for ship size
1 Tun
Ship size ready reckoner:
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