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
only
btheeenstaelmreaandyd
sfitxeernd tpoerhtieernbsrnfoadtshiedevse, gslseealvtinn
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, 1,250 horse power, under
construction at Chatham dockyard. The Lumber 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-
icch timbers up and down. Over these, again, will
be laid the 41-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 2-1-in. 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 flatter on the floors than
either the Black Prince or Warrior ; her engines
and machinery will also be placed about 2ft. lower,
and nearer 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. E. 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 Megmra 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 Whines:composition, 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 Buchans 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
er
but hay.,
foreign matter to an iron ship's bottom,
Elation to"
actually, or apparently, assisted the folrle
comPg"
growth on it of marine incrustations.
.s‘
the
chief
Lion prepared by the Admiralty °heeler' it:na which,
ingredient of which is oxide of cfopmp m
slta and the
according to the official reports
the
far its pre-
homeot alto-
dockyards, stands first on
rh.ie::Soem
g prop()
as or the attach-
servation and anti-fouling
rowth wee on service
gether prevent the g a vessel
ment of shell to the botrtoor the
new patent eompo-
tried
in a tropical climate.
s, dons a great superiority in
sition of Mr. Hay, "te.e-s over the ordinary compo-
anti-fouling PoPeLl has not yet been tested fully
any sea-going vessel. As the
use, butt
is
Pn
exist for comparing the three
coated with Peacock and
sointiothn
Himalla' :position, will be again placed in the
Buchan s in which the Megmra is, an
dock
lug that
opportunity
The serious damage which has been
compositions.
inflicted upon the bottoms of iron ships coated with
einbottomhoich
is