Engineering Wonders of the World
Volume I
År: 1945
Serie: Engineering Wonders of the World
Sider: 448
UDK: 600 Eng -gl.
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THE EQUIPMENT OF A MODERN SHIPYARD.
77
Fig. 20.—LAUNCH OF H.M.S. “ NELSON ” AT WOOLWICH, JULY 4, 1814.
(Rischgitz Collection.)
allowing the vessel to rest solely upon the
greased ways.
To prevent movement until the desired
moment after the knocking out of the blocks
is completed, the vessel is held by what are
commonly spoken of in the
shipyards as “ dog-shores.”
These dog-sliores, or triggers,
consist of pieces of timber wedged in between
projections on the sliding and standing ways.
When the signal “ all clear ” is given, the lady
who christens the vessel presses a button,
which completes an electric circuit, bringing
into operation some mechanical means for
removing the dog-shores, such as the falling
of a heavy weight upon them, and the ship
is free. Then comes the moment of supreme
excitement when the first movement is per-
ceived. She starts very slowly, as though
loth to leave the berth which she has occupied
for months ; but gradually she gathers way,
and amid the cheers of those assembled, and
shrieks from the steam whistles and sirens of
the tugs waiting in the river to take charge
of her, the new ship passes majestically down
the ground-ways to take the first plunge into
her native element.
In order to stop the vessel gradually after
she has left the ways, which of course is neces-
sary when the ship is launched into a river of
limited width, a series of steel _
The Drags.
wire hawsers are connected
from eye-plates on the ship’s sides to piles of
chains or other heavy drags buried in the
ground near the head of the building berth.
These hawsers become taut one after another,
drag the chains along, ploughing up the
ground, and at length bring the vessel to rest.
When sho is safely afloat, hawsers are passed
to the tugs in attendance and the vessel is
guided to her moorings, after which the work
of completion is taken in hand.
The launch of the Cunard liner Lusitania
from the yard of Messrs. John Brown and
Company, Clydebank, and of the sister ship
Mauretania from Messrs. Swan, Hunter, and