Steamships and their storyChatterton, E. Keble (Edward Keble)
History
Steamships and their story
Chatterton, E. Keble (Edward Keble)
Shipbuilding; Steamboats
Turning our attention away from the North Atlantic for a while, we
shall be able to see that steamships on other routes were now fast
passing from the olden types, when designers and builders were working
with only a minimum of data on which to base their achievements. We
have already referred to the highly important knowledge which was
gradually being obtained concerning the relations between the hull
of a ship and the water in which she is floated. One of the greatest
authorities on this subject about the middle of the last century was
John Scott Russell, who worked out a theory regarding the resistance
of the ship passing through the water. He it was who contended that
the hull should only move the water out of the way sufficiently to
allow the widest section of the ship to pass through, and to do this
in such a manner as should cause the least amount of friction and
disturbance of the water, so that, when the ship was gone by, the
particles of water should be restored to their original quietude. It is
important to bear in mind that the design of a ship must be made with
regard to the speed which it is intended to get out of her. Thus, it is
now a well-known principle that to give a ship highly powerful engines
so that she is forced beyond her proper speed only makes the waves
diverge from the sides and waste themselves instead of travelling with
the vessel and giving it a forward impetus.
The model of the hull in the illustration facing page 134 represents
the steamship _Victoria_, which was built in 1852 of iron, and designed
by those two great geniuses Brunel and Scott Russell for the Australian
Royal Mail Steam Navigation Company. Even the least practised eye on
looking at her lines can see that she possessed speed, and it was
this ship that gained the £500 prize offered by the Colonies for the
fastest voyage to Australia, her time from Gravesend to Adelaide
being sixty days, including two days’ delay at St. Vincent. The
_Victoria_ was designed as embodying the wave-line theory and for a
speed of ten knots. It is not necessary to examine this model many
moments before one realises how unmistakably the clumsy, ponderous
hulls so characteristic of earlier years were now being replaced by
sweet, graceful, non-resisting features. The hull of the _Victoria_
was separated into a dozen water-tight compartments and displaced
3,000 tons, her length being 261 feet, with a breadth of 38 feet, or
approximately seven beams to the length. She had a two-bladed screw,
and when this was not in use, and the _Victoria_ proceeded under
sail-power alone, the propeller was fixed vertically. Thus arranged,
the ship could sail 5½ knots, but it is interesting to remark that
when the screw was allowed to revolve freely the speed of the ship was
increased another couple of knots.
[Illustration: MAUDSLAY’S OSCILLATING ENGINE.
_From the Original in the Victoria and Albert Museum._]
[Illustration: ENGINES OF THE “CANDIA.”
Public-domain text, read in full here on John Shaqi.
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