In 1842, the Admiralty seriously took up the question of propellers.
The Rattler, of 777 tons and 200 horse power was lashed stern-to-stern
with the paddle yacht Electro of the same displacement and horse power.
Both ships were driven away from each other at full speed, and the Rattler
succeeded in towing the Electro after her. After this, in 1844, construction
was ordered for a screw frigate, the Dauntless, but as late as 1850, steam
was merely regarded as an auxiliary and received little or no
consideration outside that.
The use of iron instead of oak as a material for shipbuilding was
first seriously considered about 1800. In 1821, an iron steamer was in
existence and in 1839 the Dover was ordered to be built for Government
service as a steam packet. In 1841, the Mohawk was ordered by the
Admiralty for service on Lake Huron, but the first iron warship for the
Royal Navy proper was the Trident, of 1850 tons and 300 horse power, built
at Blackwall by Admiralty orders in 1843.
Iron, as a material for warship construction was looked on with
considerable suspicion, both in England and in France. Experiments were
conducted at Woolwich with some plates rivetted together like the sides of
an iron ship, these plates being lined inside with cork and india-rubber,
(the first idea of a cofferdam). It was expected that this preparation,
which was known as "kamptulicon", would close up after shot had
passed through and prevent ingress of water. This was found to be quite
correct, but the egress of shot on the other side had quite the opposite
result. The plates were sometimes packed with wood and sometimes cased
with it, but the general result of the experiments was held prejudicial to
the use of iron, which was supposed to splinter unduly compared to wood.
The importance of deciding whether warships should be built of iron
or wood was accentuated by the necessity of replacing those heavy warships
which had been converted to auxiliary steam vessels. All such proved to be
cramped in stowage and bad sea boats. So long ago as 1822, shell guns had
been adopted. Consequently, in the experiments as regards iron, shell fire
had to be taken into consideration.
In 1842 experiments were made with iron plates three eighths of an
inch thick, rivetted together to make a total thickness of six inches. It
was, however, reported that at 400 yards these were not proof against
eight inch guns or heavy 32 pounders. These matters were taken into
consideration by Captain Chads, whose official report was as follows:
"The shot going through the exposed or near side generally
makes a clean smooth hole of its own size, which might be readily stopped;
and even where it strikes a rib it has much the same effect; but on the
opposite side all the mischief occurs; the shot meets with so little
resistance that it must inevitable go through the vessel, and should it
strike on a rib on the opposite side the effect is terrific, tearing off
the iron sheets to a considerable extent; and even those shot that go
clean through the fracture being on the off side, the rough edges are
outside the vessel, precluding the possibility of almost stopping
them."
Modifications were introduced in 1850 but Captain Chad was
"confirmed in the opinion that iron cannot be beneficially employed
as a material for the construction of vessels of war." As a result of
this 17 iron ships were condemned and it was decided that ships must be
built of wood, and that iron was disadvantageous in any form.
It was during the Crimean War where the French had constructed 5
floating batteries carrying armour which helped destroy the forts at
Kinburn in October 1855 that Britain decided to build 4 copies of the
French batteries.
