The Sun.
London, England, 1862-11-06 00:00:00

711 E NAVY.

The iron-plated frigate Royal Oak, 1,000 horse
power, preparing for sea at Chatham, is getting ra-
pidly forward ; the last row of armour plates have
been already fixed to her broadsides, leaving only
the stem and stern portions of the vessel to be en-
cased. She has several hundred hands employed on
her, and from the energy with which the work of
plating and fitting is being pushed forward, will be
ready to be undocked early in the ensuing year.
Yesterday a body of 50 additional shipwrights,
together with a large number of labourers, holders
up, and other workmen,
,were placed on the iron
steam-frigate Achilles, 1,260 horse power, under
construction at Chatham dockyard. The number of
hands now employed about that vessel is close upon
900, 250 of whom are dockyard shipwrights who
have acquired suffi3ient knowledge of iron ship-
building to justify their being employed on the new
iron frigate. The midshipe portion of the iron plates
or skin of the vessel, having all been rivetted, the
operation of fixing the teak backing, on which the
exterior armour plates will be laid, was commenced
yesterday. Between the inner and outer plates of
the vessel's side will be laid a backing of teak 18in.
in thickness, composed of two planks, the 10-inch
baulks of timber being fixed fore and aft, and the 8-
inch timbers up and down. Over these, again, will
be laid the 42-inch armour plates, giving, with the
interior plates, a solid thickness of iron and teak of
between 23 and 24 in. In this respect the Achilles
will be constructed differently from the Warrior and
Black Prince, both of which vessels have their plates
fixed amidships only, leaving the stem and stern en-
tirely unprotected. In the Achilles every portion of
the exterior of the vessel's side will be covered with
armour plates, which towards the stem and stern
Will not exceed 21in. in thickness, those portions of
the vessel being least exposed. To lessen the tendency
to roll common to all our large iron ships of war, the
Achilles is constructed flutter on the floors than
either the Rlack Prince or Warrior ; her engines
and machinery will also be placed about 2ft. lower,
and n=earer her kelson. It is intended to give the
Achilles an additional mast, in order to render
her more manageable when under canvas than the
Warrior, which, it is now generally admitted, would
have her sailing qualities improved by being pro-
vided with a fourth mast. Although the Achilles
will be furnished with one more mast than her sister
ships, the amount of canvas she will spread will
scarcely exceed the Warrior's. The trim of the new
frigate will be improved, and the sails being some-
what smaller than in our other large iron ships, the
operations of reefing, shortening, and making sail
will be attended with considerably less labour and
difficulty. From the progress already made there is
every probability of her being ready for floating
out of dock by the end of next year. It will be 12
months later before she will be ready to proceed on
her first cruise,

The Himalaya screw troopship, Capt. B. Lacy,
under repair in her machinery department, will be
temporarily undocked to-day to admit of the Resis-
tance,l6, iron ram, being docked for the examination
of her Kingston valves. The Himalaya goes into dock
again on it being vacated by the Resistance, to re-
ceive a new stern tubing and lignum vita; lining for
her screw shaft now being prepared for her. The pro-
peller of the Himalaya, which is of iron, and was
cast at Keyham on the improved Griffiths pattern
of blades, has the leading edge and tip of each blade
on their four sides honeycombed in a most extra-
ordinary manner, they having the appearance of
wood destroyed by worm perforations. An eluci-
dation of the cause of this partial destruction of the
blades by Mr. Griffiths would be interesting as re-
lating to the action of the screw propellor.
The Meg era screw troopship, Commander Hen-
derson, has been placed in dock at Portsmouth and
her bottom examined by the master shipwright and
his staff for the purpose of preparing a report for
the information of the Admiralty on the respective
and comparative merits of the two descriptions of
anti-fouling composition with which it was coated
in April last. The starboard side of the ship was
then payed with the ordinary composition pre-
pared by Mr. Hay, the Admiralty chemist, and the
port side with the Wlnneslcomposition, as used on
the bottoms of the Cunard steamers. Without an-
ticipating the decision of the Government authori-
ties as to the comparative merits of the two compo-
sitions, we may state that both sides of the ship are
unusually clean and free from marine incrustations,
taking into consideration the length of time the
compositions have been on. Since 1845, however,
when experiments with protecting and anti-fouling
compositions for the bottoms of iron ships com-
menced at Blackwall, on her Majesty's screw yacht
Fairy, with the compositions of Baron Wetterstedt,
Mr. Owen, and Mr. Ditchburn, up to the present
time, when the preparations of Mr. Hay, M'lnnes,
and Peacock, and Buehans are those exclusively ap-
plied to seagoing vessels in her Majesty's Navy,
not one has been found to answer in all the neces-
sary requirements, Many of the compositions
have not only failed to prevent the adhesion
but have
foreign matter to an iron ship's bottom,
and
actually, or apparently, assisted the formationsi-
The ooroK
tried
growth on it of marine incrustations.
t, the chief
tion prepared by the Admiralty chenlisand which,
ingredient of which is oxide of celcaPc.,rva
lta and the
list for its
home dockyards, stands first on
according to the official reports ftri:
g properties,
pre-
servation and anti-foulin
ds or the attach-
gethergrowth of Vree
on service
prevent the of a vessel not alto-
meat of shell to the bottom For
does
Patent compo-
sition a tropical climate. c
sition of Mr. Hay, hteies
iairnst eg
newre t uperiority in
over the ordinary compo-
sition
has not yet been tested fully
anti-fouling
sition in use, but
on the
l bottom
f
any sea-geing vessel. As the
H
coated with Peacock and
Bui Himalaya,
Nv hic
composition,
will be again placed in the
dock adjoining
that in which the M
egtera is, an
opportunity will then exist for comparing the three
t
compositions. The serious damage which has been
inflicted upon the bottoms of iron fillips coated with