The Earl of
Abergavenny
The Earl of Abergavenny was an East Indiamen
ship built in 1796. On the 1st February 1805, she
sailed from Portsmouth heading for the Bengal
and China. Three days later she sank with the loss
of 300 people.

Why do you think that she sank?

What evidence would you need to make a
decision?

What questions should you ask?
At 5pm, the crew thought there was no danger.
Then the ship’s carpenter discovered a serious
leak and the pumps were set. No distress signal
was released because it was not thought to be too
serious.
By 6pm more leaks were found and the ship was
thought to be in serious trouble. Signal guns were
fired but by 10pm the ship was full of water and
began to sink.
On the 4th February, near Portland Bill, the wind
dropped and the tide took the Earl of Abergavenny
towards breakers. (Rough waves over shallow
rocks).
At 11pm a rough sea hit the ship and she quickly
sank before most of the passengers and crew had
reached the lifeboats.
Write your hypothesis on the next page.
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Why do you think that The Earl of Abergavenny sank?
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Ship building
At the time that the Earl of Abergavenny was
being built, a number of changes were taking
place in ship building. The ‘knee’ (the part of the
ship joining the deck to the hull) of ships used to
be made of wood. Now they were being built of
iron for extra strength.
Could the iron ‘knees’ have caused the ship
to sink?
Write your new hypothesis below.
Have you changed your hypothesis?
Why do you think that The Earl of Abergavenny sank?
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Composite ships (ships using wood and iron) were
being built at this time and did not show any real
problems with rusting.
Sir Francis Drake’s ship, the Golden Hind, was
built in a similar way and survived over 100 years.
This means that the iron knees can’t have just
rusted away.
The only way to find out what happened was to
dive to the ship and investigate further.
Look at the following page for information
about the dive.
A cross-section of a composite ship showing more
advanced iron and wood construction.
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Diving to
the ship
The dive to the ship was obstructed by poor
visibility and the fact that the knees were very
heavy to raise.
Eventually a number of knees were brought to
the surface to be analysed.
Analysis of the knees showed far greater
corrosion (rusting) had taken place than was
expected. The knees had worked loose around
the pins that held them to the hull and deck.
This allowed the planks of the hull to move and let
in water, causing the ship to sink.
Why did the knees rust so quickly?
Chemical analysis showed that the pins used were
not made of iron but were cheaper copper.
Did this make the difference?
Raising the knees.
A photograph of the pin hole on the iron knee.
Large amounts of rusting can be seen.
Go to the next page to update your hypothesis.
Salvaged knees (taken from another dive).
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Have you changed your hypothesis?
Why do you think that The Earl of Abergavenny sank?
You can look at your previous hypotheses on
pages 2 and 3.
Go to the following page for your next piece of
information.
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Sacrificial
Anodes
Modern ships are now made of metal. There are a
number of methods to prevent them from rusting.
Sacrificial anodes are small blocks of metal
(normally magnesium or aluminium) which are
bolted to the hull.
The blocks corrode whilst the ship stays safe.
Sacrificial anodes made from Magnesium.
See the following page for the last piece of
information.
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The reactivity
of metals
The reactivity series of metals
K
Potassium
Na
Sodium
Ca
Calcium
Mg
Magnesium
Al
Aluminium
C
Carbon
Zn
zinc
‘Rusting’ corrosion can be prevented by
connecting iron to a more reactive metal (eg Zinc
or magnesium). This is referred to as sacrificial
protection or sacrificial corrosion.
Fe
Iron
Sn
Tin
Pb
Lead
H
Hydrogen
The more reactive metal in the pairing is
preferentially oxidised away (corrodes), thus
protecting the other metal, leaving it intact. The
picture above illustrates what would happen after
a few days.
Cu
Copper
Ag
Silver
Au
Gold
Pt
Platinum
How does this compare to the iron knees on the
‘Earl of Abergavenny?
(added for comparison)
Most reactive
Least reactive
Go to the following page to write your final
hypothesis.
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What is your final hypothesis?
Why do you think that The Earl of Abergavenny sank?
You can look at your previous hypotheses on
pages 2, 3 and 6.
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registered in England and Wales (number 3644723). Our registered address is AQA, Devas Street,
Manchester M15 6EX.
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