The Sun.
London, England, 1866-03-20 00:00:00

FULL-BOILER POWER.

Time. Speed of ship.
No. of Run. 1. 4 min. 4 sec. 14.634 knots.
2. 4 „ 22 „ 13.740 „
7,
3. 4 „ 2 „ 14.876 „
4. 4 „ 29 „ 13.383 „
17
~ 5.
3 77 56 77 15.354 „
77 6. 4 „ 37 „ 12.996 „
Mean speed of the ship at full-boiler power, 14.227
knots, maximum revolutions of the engines, 70.5 ;
maximum, 70 ; steam pressure, 261 b ; vacuum,
23.5 inches.

lIALF-BOILER POWER.

No. of Run, 1.
77 2.
II 3.
4.

Tim©.
4 min. 0 sec.
6 15 9 ~
4 „ 12 „
6 7, 5 71

Speed of ship.
15-0 knots.
9.756 „
14.285 „
9.863 „

Mean speed of the ship at half-boiler power, 12.226
knots, maximum revolutions of engine, 59 ; mini-
mum ditto, 47. In turning the circles the ship dis-
played extraordinary activity, under the influence
of her helm, and they were made at full and half
boiler power as follows :—To starboard—Full power.
—Ship's helm up in 60 sec. ; angle of rudder, 36
deg. ; men at wheel, 6 ; half-circle made in 2 min.
13 sec.; full ditto, 4 min. 28 sec. ; revolutions of
the engines, 67 to 60. To port.—Ship's helm up in
41 sec.; angle of rudder, 34 deg. ; men at wheel, 6 ;
half-circle made in 2 min. ; full ditto, 4 min. 22 sec. ;
revolutions of engines, 67 to 60. Half-boiler power.
—To port.—Ship's helm up in 35 sec. ; angle of
rudder, 35 deg.; men at wheel, 6 ; half-circle made
in 2 min. 32 sec.; full ditto, 5 min. 11 sec. ; revo-
lutions of engines, 56 to 48. To starboard.—Helm
up in 40 sec. ; angle of rudder, 31 deg. ; men at
wheel, 6; half-circle made in 2 min. 28 sec. ; full
ditto, 5 min. 14 sec. ; revolutions of engines, 58 to
51 ; diameter of circles, 550 yards.
The engines were stopped to order from time of
moving telegraph handle in 26 sec., started ahead
in sec., and turned astern from full speed ahead in
24 sec.

The indicated horse-power of the engines was not
worked out in full, but it exceeded 6,100-horse, over
six times the nominal power of the engines—the
greatest proportion of indicated to nominal horse-
power yet achieved by any screw engines. In the
preliminary trial of the ship and her machinery on
Friday last the indicated power of the engines was
6,035 ; nominal power of the engines is 1,000-horse.
They have been designed and built by Mr. Penn, at
about 10 per cent. less weight than others of the
same power, and at the same time were intended to
develope 6,000 horse on the indicator cards, with a
maximum number of revolutions of the engines of
70. The steam is superheated, and then expanded
greatly, and finally condensed with surface con-
densers. The cylinders have a diameter of 112 in.,
a diameter of trunk of 41in., and an effective disc
of 104; in.-8,535.756 area in square inches. The
condensers contain upwards of 14 miles of tubing,
having an interior diameter of bore of It is all
but superfluous to say that the engines of the Belle-
rophon are magnificent specimens of metal work,
and their performance yesterday was fully equal to
their appearance, and the world-wide reputation of
their makers. To this efficiency of her machinery the
speed of the Bellerophon yesterday is in no small
degree due. The " heaped up wave of broken
water," as it is termed by Mr. Reed and M. Dupuy
de Lome, was yesterday present in front of the Bel-
lerophon's bows in full strength when she was run-
ning over the mile course at full boiler power, run-
ning up level with her hawse-pipe, fully Oft. above'
the surrounding water level. The result of the trials
at full and half boiler power, highly satisfactory as
they were, does not settle the question of the dis-
puted merits of the Bellerophon, nor can they be
defined with accuracy until the next trial, which
will be made at her seagoing draught. The plain
results of yesterday's trial may be considered to be :
—l, The development of power by the engines, in
proportion to others of the same weight and ton-
nage, unequalled on any previous occasion ; 2, a
speed attained by the ship on her light trial half a
knot in excess of what had been anticipated.

The propeller used yesterday was an imperfect
two-bladed Griffiths' of 23ft. Gin. diameter and 21ft.
pitch. Its imperfection consisted in its two blades
being of iron, cast by the Messrs. Penn, at a pitch
of 23ft. Gin., and set on a square loss, in lieu of the
ordinary sphere, as fitted to all perfect Griffiths'
screws. A new and perfect Griffiths' will now be
provided for the ship of metal by the Messrs. Penn
to Admiralty order. _ _

As a means of comparison, we subjoin here the
results of the trials of our latest ironclads, exclusive
of the Agincourt :—Achilles—drew 25ft. 11in. of
water forward, and 26ft. llin. aft; speed, 14.322
knots. Black Prince—drew 26ft. of water forward,
and 27ft. aft. ; speed, 13.502 knots. Prince Con-
sort—drew 23ft. Bin. forward, and 25ft. Biin. aft;
speed, 13.199 knots. Minotaur—drew 23ft. lin.
forward, and 24ft. lin. aft ; speed, 14.781 knots.
Warrior—drew 25ft. 6in. forward, and 26ft. sin.
aft ; .speed 14.356 knots.
The Warrior, at seagoing draught of water, still
remains the fastest
_ship under steam in the British
navy. The Minotaur was tried at light draught
only ; so was the Agincourt. The Warrior was
tried only at deep-load draught. She has yet to
stand comparison with the Minotaur, Agincourt,
and Northumberland in their deep-draught trials ;
but the Bellerophon cannot be, nor ever was, ex-
pected to equal her.
After the trials of the frigate had been brought to
a conclusion Mr. Penn entertained the officials and
the company on board to luncheon in the wardroom
of the ship, where the usual exchange of congratula-
tory speeches took place. Mr. John Penn expressed
his extreme gratification with the working of the
ship's engines, and said that it was the first time in
his professional career that he was enabled to say
conscientiously that he felt perfectly satisfied and
unable to find a fault or suggest an improvement.
Mr. Reed, Chief Constructor, and designer of the
ship, in a speech of considerable length, referring
to the various vessels he had designed for the Ad-
miralty, said that in designing the Bellerophon he
had entered the field against the long, unhandy
ships of the Minotaur class, and endeavoured in the
Bellerophon to combine speed with handiness, that
while a ship should have the maximum amount of
manceuvring power she should be but little inferior
in speed to the ships of 380 ft. and 400 ft. in length,
the Bellerophon's length being 300 ft. Mr. Reed
also complimented Mr. Penn on the working of the
ship's machinery, and stated that it was economy in
the Admiralty to give Mr. Penn an extra price per
horse-power for engines that could drive ships of
moderate length, at a speed all but equal to ships of
one-third greater length and unwieldy in the extreme
from their disproportionate length.
The frigate has attracted much attention since her
arrival at Portsmouth. A vessel of almost preter-
natural ugliness was expected, which, when first
seen quietly anchored at Spithead, turned out to be
a bold, handsome-looking, well-rigged three-masted
ship, with a bow on her, as seen from a distance,
very like that of a monster China clipper, and a
stern as graceful as could be wished in the conical
armoured finish of the after end of an ironclad. A
nearer view of the ship discloses the nose of the
submerged bow, which could not be seen from a
distance, but even this bit of positive ugliness does
not destroy the effect of the graceful sheer of the
ship's outline overhead.
from below the
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about 100 ft, on each
of ,
her sides covered with ar-
mouraanndunis,arcmonosureqeudensthlyi;
for,
above her 100 ft. on each side
rwa
vulnerable
belt of
exte to
s
armour, and throughout this space
shells. The water-line belt of armour extends
round the ship upwards to the beams on which the
gun-deck planking is laid, and the bows and stern
of the vessel in all parts as seen direct from ahead
or
a ead
or astern are also incased in armour, two ports being

fitted at each end, through which four 6k-ton Tin.
rifled guns will be mounted, to fire in a line with
the vesr3el's keel. The central armour on each side
of the ship is the side armour of the main battery of
the ship enclosed in a space about 100 ft. in length
by tlLie breadth of the ship by a 51in. armour-plated
blf.ikhead thrown across the gundeck at each end of
the outer plating. Sitting in a boat alongside the ship
it is impossible to detect where the line of plating
begins on the ship's hull or where it ends, so beau-
tifully is the work finished, The lower masts of the
ship are of iron, and all spars above them, with the
exception of the three topgallantmasts, the wizen
topsailyard, and the studdingsailbooms, are of steel.
The general smartness of the rig adds greatly to the
outward appearance of the ship. Inboard, the ship
appears to much greater advantage than when viewed
externally. Those portions of the main deck for-
ward and aft of the central battery, where the offi-
cers and crew mess and sleep, are of unusual height,
and have an amount of light and ventilation beyond
that of any other ship in her Majesty's navy. The
ship's battery 'occupies a central position between
these two portions of the deck, and is entered by an
ascent of two steps at each end from the mess deck.
The guns, 10 12-ton wrought-iron 9-inch rifles, will
be mounted in the battery 15ft. apart, and will be
trained by the machinery on Mr. Reed's plan, which
is fitted to each gun. The gear is somewhat heavy
and costly, but it has the advantages of having none
of its parts on the gundeck except a radial arm of
metal, which works in a slot underneath the gun
slide, and the six men who work it are placed with
the working gear on the deck below the battery, out
of all danger from the shot or shell of an enemy.
In point of comfort to the crew the Bellerophon's
arrangement of her main deckis immeasurably supe-
rior to that of the Warrior, Minotaur, and other ves-
sels whose crews mess between the guns on the battery
deck. When the Warrior was in commission and the
ship was coaling it could only be effected by render-
ing the mess-deck dirty and uncomfortable to the
crew. At quarters, too, the men's messes were all
capsized to give room for working the guns, and this
was another piece of discomfort to the men, who
were often heard lamenting the loss of the wooden
frigates, which gave them a clear lower deck to mess
and sleep upon, and kept all above that for duty.
In the Bellerophon the ship is coaled through the
battery only, and the mess-deck is never disturbed
or covered with coal dust. At quarters, too, her
crew simply walk out of their messes into the battery.
The men's messes, therefore, under the new condi-
tion of things on board the ship, can be kept as
permanently clean, dry, and comfortable as in the
best days of the wooden frigate, and with an un-
limited supply of air and light. In all the fittings
of the frigate the old dockyard rules of " ponde-
rosity" of material, without any reference to utility,
have been abandoned, and the eye can rest on
nothing in which lightness combined with strength
has not been the guiding principle.
The frigate altogether, in workmanship and finish
of her hull and fittings, far exceeds anything of
the kind seen previously at Portsmouth. She is a
great credit to the skill and abilities of the officers
and workmen of Chatham yard.