Strange armour

Curiosities from the scrap folder

A Cork Ship.—The Mobile papers report the arrival of a great curiosity at that city, a vessel made entirely of cork, which is lying at one of the wharves. That she will never sink may be true enough, but the other claim of the Mobilians, that “she will last forever,” requires some proof.
— Scientific American, April 28, 1866, p. 276.

Charles Atherton was the Chief Engineer at Her Majesty’s Royal Dockyard, Woolwich. When he wrote to The Times in January 1859 about his idea for filling vessels with of light material, up to the waterline, people paid attention. Essentially, he wanted to ensure that no matter how badly holed a ship was, it would never settle lower in the water, because no shot, no reef, no ram could harm the bottom layer. Gunboats, floating-batteries and mortars would all become unsinkable, so long as the guns and crew survived. Suitable solids might be:

…cork shavings, light wood sawdust, rush stems, cotton waste, flocks, hemp, and other lightweight material, which, by the aid of a solution of gutta percha or other chemical process, would form a solidifying mass, so tough that it could not be knocked to pieces by shot, and so light that it would only be one half the specific gravity of water, and therefore, unsinkable, however perforated by shot… 

— The Times Wednesday, Jan 12, 1859; pg. 6; Issue 23201; col E.

While he was concerned with warships withstanding fire, if Atherton’s solution had been applied to the “unsinkable” Titanic, it would have stayed afloat. The usual maritime practice of putting heavy items as low as possible, in order to move the centre of gravity down is an effective way of enhancing stability, but it takes a toll by increasing a vessel’s sinkability.

At the end of the year, Scientific American mentioned the scheme, but the writer said that cork would not suit, because heated shot could set fire to it, but that a suitable material ought to be able to be found. Half a century on, most lifeboats were fitted with sealed cork-filled compartments and self-draining seacocks to keep them afloat under the worst of conditions, but armour and armour-plating became the preferred solutions.

Mind you, if you knew where to look, the idea had been around for quite a while. The New York Times reported on an old patent in 1862, giving the date of issue as March 19, 1814. (‘The First Iron-Clad’, New York Times, May 30, 1862.)

The following day’s issue of Scientific American stated that a plan for a ball-proof vessel had been patented, “forty-eight years ago”. In each case, the patentee is said to be one Thomas Gregg, and the thrust of the report in each case was the same, that the idea behind the Merrimac (a Confederate ironclad warship) was by no means new.

It has to be said that this was during the US Civil War, and there is no evidence in the on-line records of the US Patent Office of Mr Gregg or his design. Perhaps it was a piece of wartime propaganda? The design and the illustration from Scientific American appeared again in 1889 in the Pittsburgh Dispatch, in an article sponsored by Gregg’s family.

It was in the early years of ironclad-mania that the attempt was made to dress warships up in sheepish clothing. In the 1860s, Australian wool growers were shearing huge flocks, and there must have been some fear of a glut. How their hearts must have sung when they heard that the Royal Navy was testing compressed wool as a way of blocking shot that hit their ships.

The plan was apparently to give ships a fleecy coat of pressed wool, 10 or 12 feet thick. Sadly, the graziers’ hopes were dashed when after tests, The Times reported in March 1864 that “the experiment of Wednesday proved the wool rather more permeable to shot than almost any other novelty that has yet been fired at.”

Every ship that sails the oceans represents a compromise. Sailing vessels had to trade off a reduction in strength from thinner hulls in order to float higher and sail faster—or to carry more cargo. A broad-beamed vessel would carry more cargo, but it would wallow along, losing time. That brings me to shipwrecks, and I shall go there next.

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