The Sun.
London, England, 1858-09-27 00:00:00

FLOATING DERRICK MACHINES.

On Saturday the launch of an iron vessel of most
singular form and construction took place from the
yard of the Thames Ship-building Company, Black-
wall, and created a great deal of interest, not only
amongst nautical and scientific men, but amongst
the population of the neighbourhood.
Ono would naturally infer, on learning a vessel had
been launched from a ship-building yard, that it
possessed some of the characteristics and was de-
signed fer some of the uses of an ordinary ship ;
but such a conclusion would be quite erroneous in
the present instance, for our vessel has neither
stem nor stern, nor paddle nor screw, nor mast nor
tackling, nor any of the usual accompaniments of
barque, sloop, or steamer. In shape it has not the
graceful, gradual swell of a ship ' • neither is it
circular, elliptical, or quadratic in form. It is a
floating rhombus, and if one were to speculate, a
priori, on its possible uses, the conjectures which
might be formed on that head would seem to be
inexhaustible. If peace had not just been concluded
with the Celestial Empire, the vessel would cer-
tainly be considered a gallows for the use of the
piratical floating population of the Canton river,
and the appellation " Derrick," which was the
name of a notorious Tyburn executioner in the
early part of the 17th century, would have given
vrazsemblance to such an ingenious hypothesis. It
might also, without much eccentricity of hypothesis,
be taken for a telescopic apparatus expressly for
observing the comet, or for a floating light-house,
or coal depot in mid-ocean ; for a Sartorius shot-
proof battering ram; for a strange whaling ship,
or for a satellite of the Great Eastern, with which
wonderful vessel it will divide the curiosity and
speculation of the Thames travelling population.
The floating Derrick has been constructed, how-
ever, for the very practical and useful purpose of
raising sunken vessels, and its invention is due not
to the fanciful projectors of Lagado, but to the
practical engineers and ship-builders of York.
To Mr. Bishop, an ingenious American, is due the
merit of the invention.

For some years past it has been extensively em-
ployed in the United States as a transportable or
moveable apparatus for raising heavy stones for
masonry, such, for instance, as that of the cele-
brated High Bridge, which forms a part of the
aqueduct for carrying the supply of Croton river
water to New York. It has also been very gene-
rally used as a stationary machine for wharves and
piers, and in hoisting boilers and machinery into
ships fitting for sea, and in dismasting and remast-
ing vessels of all sizes. At the Brooklyn Navy Yard
of the United States it has superseded for this latter
purpose the old form of " shears." Lastly, the
principle has been applied on floating vessels for the
purpose of raisins sunken ships. It was in the last
of these applications that the Derrick was intro-
duced to our notice on Saturday. In various parts
of the United States 16 of these machines—trans-
portable, stationary, and floating, possessing a hoist-
ing capacity of over 2,300 tons—have been con-
structed and worked for several years, to the entire
satisfaction of the parties owning them. Two of
these were erected for the United States Govern-
ment, and of two others belonging to the New York
Derrick Company, one had raised and saved nearly
400 sunken and stranded vessels, -while the other

had hoisted and placed on board the engines and

boilers of over 300 steamers. A short time since
the Ericsson steam-vessel,- of 2,300 tons, which, it
may be remembered, was to have accomplished such
important revolutions in marine locomotion by
means of heated air, was raised by means of this
machine, the vessel ha ving unfortunately sunk, with
all its machinery, off the coast of New Jersey.
The merits of the machine, therefore, have been
fully tested, and it is now introduced into the coun-
try by means of a company formed under the Li-
mited Liability Act, called the " Patent Derrick
Company (Limited)," The necessity which existed
in England for a machine of such a character is evi-
denced by the fact that the total number of casual-
ties reported as occurring last year in this country
was 1,141, representing a burthen of 176,544 tons
of shipping and steamers combined. Of these 1,141
vessels wrecked on our coasts there were 963 British,
116 foreign, and 11 colonial. It is calculated that
very nearly 800 out of these 1,141 vessels could have
been raised and saved, had such a fleet of these
Derricks existed as it is now sought to construct
and organise by means of the present undertaking,
upon a capital of £250,000.
The vessel, or rather the machine, consists of
a hull or " scow" of a most singular construc-
tion. If our readers will imagine a square iron
surface, each side of which is 90 feet in length,
or 10 feet wider than the Great Eastern steamer,
and upon each of two opposite sides of this square
will construct an equilateral triangle, they will then
be able to form an approximate idea of the level
surface of the deck of this extraordinary " scow."
The proportions will not be quite correct, but pretty
near, the exact figures being for the length of the
hull or " scow" 257 feet, and its greatest width of
beam 90 feet. Both stem and stern arc precisely
alike in form; they arc wedge-shaped, the greatest
width being at about (15 feet from the centre or
midships. This hull is wall-sided or perpendicular,
and the bottom—perfectly flat—is of course of the
same dimensions and area as the deck, and the
depth of hold is 14 feet. The hull is formed entirely-
of water-tight compartments, and strengthened by
being constructed upon the cellular principle. In
order to secure additional strength a wrought iron
arch, formed of plates of iron, passes from stem to
stern—or rather from one end to the other, for,
properly speaking, the thing has neither stem nor
stern—and fastened by upright and diagonal tie-
rods and supports; and two arches similar in con-
struction cross the ship diagonally, and intersect
each other in the centre of the length and breadth.
of the " scow." The largest of these cast-iron ellip-
tical arches has a span nearly as great as the centre
arch of London-bridge. Within the hold of the
" scow" are placed two propelling steam-engines,
and two others for working the gear for raising
the ships. The huge thing will be moved slowly
by means of a revolving chain passing over two
large wheels placed on each side, and provided with
moveable floats, something in the manner of the
buckets of a dredging machine, and which fall as
they descend towards the water. This chain and
floats revolve in a sort of channel or sewer, nearly
90 feet in length, protected by the outer iron plates
of the vessel's side, and which dip below the surface
of the water. There is a rudder at each end, but
the " thing" will carry no sails, and when required
to be moved will have to be towed to its destina-
tion. The " scow" or hull possesses a dead weight
of 750 tons. From its pecnliar construction the
" scow" has a very light draught of water, not ex-
ceeding 30 inches. When launched: on Saturday
it was necessary to pump 300 tons of water into
the hull to keep it sufficiently steady under the
weight of its top-gearing.
On the basis of this enormous float the Derrick
crane, or hoisting apparatus, is fixed. It consists
of five iron legs, formed of inch-and-a-quarter plates
of iron, which support, at a height of 50 feet, the
enormous hoisting " boom." This boom is 120 feet
in length, and its broadest part is 30 feet in breadth.
It is formed of thick plates of iron rivetted together,
and which, seen front below, appear as though one
of the Thames steamers had' been taken up bodily
and placed in the towering platform above.
Through a hole in the centre, this forming the pivot
upon which the boom turns, is the great " king
post," in the interior of which a game of chess was
boom"ientl played.isfi ftfeet,y T he
an and height
i.t
is
there recently
postnt I 3
avtro3slemtlileve`?
surmounted at the top by a huge block of iron
weighing twenty-five tons, to which the chains
which support the ends of the " boom" are at-
tached.
The legs, which support the whole of the
are weight, secured by braces and diago-
nal ties. height from the deck to
the
esnly
the top of the " king post" is 130 feet, The
following are the particulars of the dimensions and
weight of the.various parts of this extraordinary

* 4th Dragoon Guards,'sth ditto, lit Dragoons, 2d ditto
(Grays), Ist Dragoon Guards, from 5 ft. 8 in. to 5 ft. 11 in. ;
2d Dragoon Guards, 3d ditto, 7th ditto, sth Lancers, 6th
Dragoons (Enniskillens), 9th Lancers, 12th ditto, 16th ditto,
17th ditto, from 5 ft. 6 in. to 5 ft. 8 in. ; 6th Dragoon Guards
(Carabineers), 3d Light Dragoons, 4th ditto, 7th Hussars,
Bth ditto, 10th ditto, 11th ditto, 13th Light Dragoons; 14th
ditto, 15th Hussars, 18th ditto, from 5 ft. 41 in. to 5 ft. 6 in.,
age rom 18 to 30 years.