Worm turned on the Navy
QUESTION The teredo has been described as ‘the clam that sank a thousand ships’. Just how big a problem was this creature for the Royal Navy?
To GIVE it its full name, teredo navalis, or the ‘naval shipworm ’, has a worm-like appearance, but it is, in fact, a saltwater clam. P robably originating in the North Atlantic ocean, it is found in most temperate and tropical seas and oceans.
t. navalis can grow up to 60cm long and to a diameter of 1cm to 2cm. it has exceptional burrowing qualities and can live in a wide range of temperatures.
The question aptly describes t. navalis as ‘the clam that sank a thousand ships’.
it wasn’t just ships that got attacked, but piers, jetties, dykes — anything wooden. There are reports of the creature damaging ships going back to Columbus.
During the Age of sail, this clam was one of the biggest problems for wooden sailing ships. Entire ships’ hulls were eaten away relatively quickly. Many ships were leaking by the time they arrived in the West indies; sometimes, whole ships were lost to the ‘worm’.
The warmer the climate, the more voracious an appetite it seemed to have. This worm was up there as a problem for the Royal Navy with yellow fever and the French!
Deterioration of the hull of a wooden ship was a big problem, due to infestation, weeds and wet rot. These affected a ship’s handling and fighting capability.
Many types of hull protection were tried: wood sheaths, pitch, tar , hair and yarn. in 1761, HMs Alarm was the first ship to have experiments carried out on her using copper plates.
The Alarm was chosen as she was in such poor condition due to t. navalis. The innovation of copper sheathing kept the worm and weed at bay, enabling the Royal Navy to function around the world.
However, copper cladding was not certain protection from the ‘worm’, as this poem by Henry David Thoreau (18171862) attests: ‘The vessel, though her masts be firm / Beneath her copper bears a worm / Around the cape, across the line/ . . . Far from New England’s blustering shore / New England’s worm her hulk shall bore / And sink her in the indian seas . . .’(Though All The Fates).
Peter N. Lockyer, Gosport, hants.
QUESTION Why is the Royal Signals Badge of Mercury nicknamed ‘Jimmy’?
i sERVED in the Royal signals from February 1960 to F ebruary 1962 for my National service.
For a long time, it was widely accepted that the badge name ‘Jimmy’ came from a popular Corps boxer called Jimmy Emblem, who represented the Corps from 1921 to 1929 and was the 1924 Army Champion. The soldiers were supposed to have said: ‘Jimmy is our emblem.’
But more recent research unearthed a document from Brigadier - General Clementi-smith Dso, who stated: ‘on my return from south Africa at the end of 1904, i was posted to the signal service RE in Aldershot.
‘This unit carried the drumstick with the figure of mercury on top. This figure was known as “Jimmy” and had been known as such for some time.’
The bandstick is on display in the Aldershot Museum.
Another theory is that it is based on a life-size bronze statue of Mercury in the Bargello Museum in Florence. similar in design to the Royal signals badge, it includes the Caduceus (Mercury’s winged staff) in the left hand. it was made between 1578 and 1580 by Giambologna (Jean de Boulogne). it ’s possible that ‘Jimmy’ was derived from his name.
Brian starkey, huntingdon, Cambs.
QUESTION What were the worst warships of the 20th century?
EARlY submarine design certainly caused a number of unnecessary deaths. However, the built-in design flaw of the battlecruiser caused more deaths than any other badly designed ship.
in order for a warship to be successful, three things have to be kept in balance: speed, protection and firepower.
The purpose of a cruiser is to attack the enemy supply lines and convoys. she needs to be fast enough to out- sail the more powerful enemy battleships and powerful enough to out-gun the smaller , faster enemy destroyers and frigates.
At the beginning of the 20th century , the Admiralty tried creating a ship with the speed of a cruiser , but the firepower of a full-sized battleship.
The only way to achieve the speed was to cut down on the armour plating . it ended up with a ship that could be described as an eggshell armed with sledge hammers.
That is why, at the Battle of Jutland in 1916, three British battlecruisers went down in quick succession to single shots fired by the German fleet, resulting in more than 3,000 deaths.
The folly of the battlecruiser design was illustrated by the sinking of HMs Hood by the German battleship Bismarck in the Denmark strait in 1941.
Both ships had eight 15 in guns. The Bismarck was accompanied by P rinz Eugen, which had eight 8 in guns.
The Hood was accompanied by the new battleship the P rince of W ales, armed with ten 14in guns. Also present were the cruisers HMs sheffield and Norfolk, both armed with eight 8 in guns.
it should have been an easy victory for the British. Unfortunately, due to a lack of armour plating, the Hood was sunk by a shell from the Bismarck that penetrated the decks and exploded in the magazine. it sank with 1,418 men aboard; just three crew members survived.
in theory, the P rince of Wales should have been able to deal with Bismarck by herself. Unfortunately, she was so new she still had civilian contractors on board sorting problems with the gun turrets. she had to withdraw from the action.
As Bismarck had the correct armour plating, it took several direct hits from the 14 in guns of King George V and the 16 in guns of HMs Rodney , and several torpedo hits, finally to sink her.
stuart Bower, hove, e. sussex.
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