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joint so that it could be lowered till the boss was level with the keel an
arrangement introduced by Sir E. J. Harland in 1871 as a means of securing
greater immersion and so preventing racing.

The engine bearers and a portion of the hull of the vessel are shown in
section, but not in detail ; an adjacent drawing, however, shows, to a scale
of 1 : 96, the complete general arrangement of the similar though smaller
machinery fitted in vessels of the fleet of the Compagnie Generale Trans-
atlantique.

,849. Model of engines of H.M.Ss. "Boadicea " and " Bacchante "
(working). (Scale 1 : 12.) Presented by J. K. Rennie, Esq.,
1876. N. 1414.

These unannoured corvettes were built at Portsmouth in 1875-6 to the
following dimensions : Displacement, 4,130 tons ; Length, 280 ft. ; beam,
45 ft. ; draught, 23-25 ft.

The engines are of the horizontal, three-cylinder, two-stage expansion,
return-connecting-rod type, with a high-pressure cylinder 73 in. diam. and
two low-pressure cylinders 92 in. diam. ; the stroke of each piston is 4 ft.
The cylinders are steam-jacketed over both barrel and ends, and the cylinder
castings are fitted with liners. Each piston has attached to it a plunger,
the bottom of which slides on a suitable adjustable bearing block, so as to
carry the weight of the piston ; the back cover of each cylinder is provided
with a projecting bonnet that clears its plunger. On the front side of each

s 2



276

piston are two piston-rods which extend past the crank- shaft and are
attached to a crosshead working on a bar guide on the port side. The high-
pressure cylinder is fitted with J. E. Outridge's patent (1868) equilibrium
slide valves and a separate gridiron cut-off valve on the side of the main
valve chest. The main slides of the high-pressure cylinder are driven by
the ordinary link motion through a rocking shaft, and the cut-off valve by
a separate eccentric through levers that give a variable travel. In order to
get the necessary port area within the restricted space, the equilibrium
valves were made double. The low-pressure cylinders were fitted with
ordinary double-ported slide valves, and these valve chests were made large
so as to serve as intermediate receivers. The engines were fitted with both
steam and hand reversing gear. The three cranks were not arranged
equally, the low-pressure cranks being opposite each other while the high-
pressure crank was at right angles to them.

There are two surface condensers containing collectively 10,214 tubes
75 in. diam. and 4*75 ft. long, giving a total condensing surface of
9,545 sq. ft. ; these tubes are arranged vertically and the steam passes
through them. The two air pumps are double-acting, with pistons 20 in.
diam., each driven by a rod from the low-pressure pistons. The condensing
water is circulated by two centrifugal pumps with fans 30 in. diam. fixed on
the backs of the condensers. Each pump is driven by a diagonal engine
with a single cylinder 12 in. diam. by 8 in. stroke ; they force the water
through the condensers and are arranged to draw either from the bilge or
direct from the sea. The bilge and feed pumps are worked directly from the
low-pressure crossheads.

Steam at 70 Ib. pressure is supplied by ten single-ended boilers 12 ft.
diani. by 9'8 ft. long, each with three furnaces, giving a total heating
surface of 14,170 sq. ft. and 625 sq. ft. of grate area.

The engines drive a two-bladed lifting Griffiths' screw 20 5 ft. diani. by
23 ft. pitch, and on trial the " Boadicea " indicated 5,300 h.p. with 74' 5 revs,
per min., and had a speed of 14 '8 knots.

850. Drawing of engines of H.M.Ss. "Iris" and " Mercury."
(Scale 1 : 48.) Maudslay Collection, 1900. N. 2252.

The " Iris " and " Mercury " are twin-screw sister vessels, designed by
fche Admiralty for despatch service and constructed of mild steel at Pembroke
Dockyard in 1876-8. Their dimensions are : Displacement, 3,750 tons ;
length (b.p.), 300ft., (o.a.), 333 ft. ; breadth (extreme), 46 -lft. ; draught
(mean), 19 -7 ft. ; midship section, 777 sq. ft. ; coal capacity, 780 tons.

The engines are of the horizontal direct-acting two-stage expansion type,
in two sets, the port engine being placed aft of the starboard one. In each
set there are two high-pressure cylinders 41 in. diam. and two low-pressure
75 in. diam., by 36 in. stroke, arranged as tandem compounds working on
cranks at right angles. The two surface condensers are entirely of brass,,
and together contain 74,000 ft. of tube 625 in. internal diam. The air and
feed pumps are arranged vertically and driven by bell-cranks worked from
the low-pressure pistons ; the two circulating pumps are of the centrifugal
type and driven by independent steam engines.

Steam is supplied by twelve Scotch boilers having a total grate area of
700 sq. ft. and 18,700 sq. ft. of heating surface. With a boiler pressure
of 62 Ib. the engines made 97 revs, per min. and developed 7,735 h.p., which
gave a record speed of 18'57 knots with four-bladed propellers 16 '25 ft.
diam. by 20 ft. pitch. Earlier trials with the larger and finer pitched
propellers shown in the drawing gave a speed of 16 knots.

851. Model of engines of S.S. " Orient" (working). (Scale
about 1 : 10) ; and photographs. Presented by J. G, S.
Anderson, Esq., 1895. N. 2060.

The " Orient," the pioneer vessel of the Orient Line, was built and
engined by Messrs. John Elder & Co. at Glasgow in 1879. She has a
displacement of 9,500 tons at load draught, and a gross tonnage of 5,386,
is 445 ft. long, 46 25 ft. broad, and 36 8 ft, deep.



277

The model shows the general arrangement of the engines ; the details,
however, have not been reproduced to scale, being modified to render the
model a workable engine suitable for driving a small launch ; the adjacent
photographs, however, represent the actual engines.

The engines are of the vertical, inverted, two-stage, surface-condensing
type, with one high-pressure cylinder 60 in. diam., and two low-pressure
cylinders of 85 in. diam., working on separate cranks arranged at 120 deg.,
with a common stroke of 5 ft. The valves are of the piston type arranged
in a chest at the back of each cylinder and driven by link-motion reversing
gears from the crank- shaft. A rocking lever for each valve transmits the
motions from the link block to the valve rod, but the three gears are simul-
taneously reversed by a single reversing shaft, which in the actual engines
is moved by a steam reversing gear.

The air, circulating, and feed pumps are fixed at the back of the engines
and driven from the two low-pressure crossheads by levers ; the condenser
is formed in the lower portion of the back standards. The engines are
supplied with steam at 75 Ib. pressure, and indicate 5,400 h.p.

852. Model of engines of S.S. "Flamboro" (working).
(Scale 1 : 4.) Made by Palmers Shipbuilding and Iron
Co. Received, 1895. Plate X., No. 3. N. 1727.

This represents the engines and propeller of the S.S. " Flamboro," built
and engined at Jarrow in 1885. The dimensions of the vessel are :
Displacement, 4,400 tons ; length, 265 ft. ; beam, 39 -6 ft. ; depth, 23 -5 ft. ;
and midship section, 730 sq. ft.

The engines are of the three-stage expansion, surface-condensing, inverted
direct-acting type, with three cylinders of the following diameters : High
pressure, 22 in. ; intermediate, 35 in. ; and low pressure, 58 in. ; all having
a stroke of 42 in., and each cylinder acting upon a separate crank, the
cranks making with each other an angle of 120 deg. The distribution of
the steam is controlled by a piston valve in the high-pressure, and flat
slide valves for the intermediate and low-pressure cylinders, driven by
the ordinary link-motion reversing gear. The high-pressure and inter-
mediate steam chests are directly above the crank-shaft, but the steam
chest of the low-pressure cylinder is placed at the front or starting platform
side of the cylinder, the valve being driven by a rocking lever pivoted on
the after column. The engines are reversed by means of a single- cylinder
steam reversing engine of the " all-round " type, combined with which is
a hand- wheel gear.

The air and circulating pumps are contained in one cast iron case, fixed
on the back of the condenser and driven from the low-pressure crosshead by
means of levers and links. The circulating pump is 12 in. diam. and
double-acting, while the air pump is 18 in. diam. and single-acting ; both
have a stroke of 18 in. The circulating pump forces the water twice
through the condenser, first through the lower half and back again through
the upper half, the water being inside the tubes. The feed pumps are
placed at the forward end of the air and circulating pumps side by side, and
the bilge pumps at the after end of the pump case ; all of the pumps are
driven from one crosshead connected to the levers and links before
mentioned.

The propeller is a four-bladed screw 15 '3 ft. diam., 17ft. pitch, and
64-8 sq. ft. in area. The thrust of the propeller is taken by a thrust
bearing with six collars on the shaft. The ends of the bearings are complete,
but between them are five horse- shoe plates that fit between the shaft
collars, thus leaving the lower portion of the shaft open to the oil chamber
below. The horse- shoes are supported upon side screws, along which each
<jan be independently adjusted so as to distribute the thrust equally between
all of the collars.

On trial the indicated h.p. of the engines was 1,125, the revs. 67 per min.,
and the speed of the vessel fully laden 10'5 knots. The working steam
pressure of the boilers is 150 Ib. per sq. in.



278

853. Motion diagram of engines of S.S. " Orinoco." (Scale
1 : 12.) Lent by the Royal Mail Steam Packet Co., 1891.

N. 1868.

The " Orinoco " is a steel-built vessel, constructed and engined by
Messrs. Caird & Co. at Greenock in 1886 (see No. 284). Her leading dimen-
sions are: Gross register, 4,478 tons; length, 409 '7 ft.; beam, 45 ft ;
depth, 25 -4 ft.

The diagram shows both the longitudinal and transverse sections of the
main engines, which are supplied with steam at 150 Ib. pressure and indicate
5,863 h.p. The engines are of the three-stage expansion type, the steam
working successively in cylinders 42 in., 62 in., and 96 in. diam. respectively,,
by 66 in. stroke. The valve motion is of the ordinary shifting link type,
but the valves of the three cylinders differ ; that of the high-pressure
cylinder is of the Trick form and has a back relief frame ; the two others
are of the gridiron construction and have vertical balance cylinders.

854. Drawings of engines of S.Yt. " Gladiator." (Scale 1 : 8.)
Lent by Messrs. Ramage and Ferguson, 1887. N. 1708.

The " Gladiator " is an iron-built steam yacht, constructed and engined
by Messrs. Bamage and Ferguson in 1886 to the following dimensions :
Register, 111 -7 tons; length, 119-6 ft.; beam, 20 '1 ft.; depth, 11-7 ft.
She is schooner -rigged, but has an auxiliary screw which is fitted with the
" Bevis " feathering arrangement, so that when not in use its resistance can
be minimised.

The engines consist of a three-stage expansion set with cylinders
9-25 in., 15 in., and 24 -5 in. diam., by 18 in. stroke, indicating 162 h.p. at
145 revs, per min. Steam at 150 Ib. pressure is supplied by a cylindrical
boiler, described in No. 900.

These engines were the first three-stage expansion set fitted with
Walschaerts valve gear (see Mechanical Engineering Collection). Each
cylinder has a single eccentric which gives the 90 deg. of angular advance
required in a valve motion, while the further advance necessitated by the lap
and lead of the valve are obtained from a lever rocked by the piston-rod
crosshead. Linking-up and reversal are done on a link that is rocked by
the single eccentric ; the gear gives a practically constant lead at all grades.
The indicator diagrams obtained are shown combined on the drawing.

855. Drawing of engines of S.S. "Prometheus." (Scale
1 : 24.) Lent by Messrs. Robert Stepheiison & Co., 1886.

N. 1698.

The "Prometheus" is an iron-built vessel, constructed by Messrs.
A. Leslie & Co. at Newcastle in 1886, and engined by Messrs. Stephen-
son & Co. Her dimensions are : Length, 321 ft. ; beam, 36 -5 ft. ; depth,
26 ft. ; with a carrying capacity of 3,000 tons on a mean draught of 23 ft.

Her engines are on the tandem two- stage expansion system, and have
a single overhanging crank and a fly-wheel on the shaft, an arrangement
introduced by Mr. A. Holt. The cylinders are 27 in. and 58 in. diam.,
by 5 ft. stroke ; the high-pressure cylinder is uppermost and has its piston
rod attached to a crosshead above, from which two rods, passing through
stuffing boxes in the low-pressure cylinder cover, extend to the low-pressure
piston ; in this way the use of an inaccessible gland between the two cylinders
is avoided. The high-pressure slide valve is of the piston type and is fitted
with Buckley's rings, while the low-pressure valve is of the ordinary flat
form; both valves are worked by the same pair of eccentric rods and the
usual Stephenson's link motion. The crank-shaft is of steel 14 in. diam.,
and has the two eccentrics forged with it immediately behind the thrust
collar. The crank cheek is of wrought iron shrunk on and keyed ; the fly-
wheel weighs 5 tons, and is used as the wheel of the turning gear, which with
a single crank engine is of special importance. It consists of a steam cylinder



279

and oil cataract attached to the bulkhead just over the fly-wheel ; the piston
rod of this " heaving-round " cylinder is square in section and is fitted with
strong steel pawls, which engage with teeth on the rim of the fly-wheel
for forward or backward motion as required. The condenser is of the usual
form and has 1,925 sq. ft. of surface, given by tubes 1 in. outside diarn. The
air pump is 18 in. diam. by 22 5 in. stroke, and is single-acting, while the
circulating pump is 13 '5 in. diam. by 22 '5 in. stroke, and is double-acting.
These and the other pumps are worked by the usual lever arrangement, but
there is an independently driven 6 in. centrifugal pump for emergencies.

Steam at 80 Ib. pressure is supplied from a double-ended boiler, having
5,015 sq. ft. of heating surface and 153 sq. ft. of grate area (see No. 898).
The propeller has four blades and is 15 '75 ft. diam. by 20*5 ft. pitch. The
ordinary indicated h.p. is 1,350 and the speed 12 knots.

Engines of this type are very lofty, but on the other hand they require
less space than a double crank engine, leaving room for from 200 to 300 tons
of additional cargo.

856. Drawings of engines of S.S. " Majestic." (Scale 1 : 16.)
Presented by W. S. Clayton Greene, Esq., 1910. N. 2540.

The " Majestic," together with her sister ship " Teutonic," was built and
engined by Messrs. Harland and Wolff in 1889 for the White Star line.
As the first vessels for this Company's service in which sail-power was finally
abandoned, they mark a stage in the development of this fleet. The
dimensions of the " Majestic " are : Displacement, loaded, 17,800 tons ;
length (o.a.), 582 ft. ; breadth, extreme, 57 -8 ft. ; depth, moulded, 42 -2 ft.

The drawings represent one of a pair of three- stage expansion engines
fitted on this vessel. From left to right on the wall the views shown are :
(1) A rear elevation, showing the condenser, 20 ft. in length ; (2) an end
elevation, from the high-pressure end ; (3) a front elevation. The engines
are of . the direct-acting, inverted type ; the cylinders, which are not steam
jacketed, being of 43 in., 68 in., and 110 in. diam. respectively, by 60 in.
stroke. All the cylinders have piston valves, the intermediate and low-
pressure cylinders having two each. Tail rods are provided for the pistons
of these two cylinders. The framing is of cast steel, and each cylinder is
supported on two frames, an A frame at the front, and a single frame at
the back. This method gives three points of support, and ensures stability.
The crank-shaft is of Whitworth steel with crank pins 22 in. by 22 in.
Yalve gear of the Stepheiison type is employed. Each set of engines has
two air pumps worked by levers from the high and low-pressure cross-
heads ; these levers also drive the bilge pumps.

The screw shafts are placed so close together that the screws, which are
19-5 ft. diarn. by 29 '5 ft. pitch, overlap to the extent of 5 '5 ft. To allow
for this the starboard propeller is astern of the other by 6 ft., an opening
being made in the deadwood to allow for this ar rangement.

Steam is supplied by 12 double-ended and 4 single-ended boilers at
180 Ib. pressure, and Howden's system of assisted draught is employed.
The total heating surface is 40,968 sq. ft. ; grate area, 1,160 sq. ft. ;
indicated h.p., 17,000 ; speed, 19 -5 knots.

857. Prints of engines of S.S. " Aska," (Scales 1 : 8 and
1 : 24.) Lent bv the Ailsa Shipbuilding Co., 1890.

N. 1846.

This steamer was built of steel in 1889 by the Ailsa Company for the
Indian coasting trade. Her dimensions are : Gross register, 527 tons ;
length, 190 ft.; breadth, 29 ft.; depth, moulded to main deck, 12 '25 ft.
(see No. 294).

The engines are of the three-stage expansion type, with cylinders 16 in.,
26 in., and 42 in. diam., by 30 in. stroke. Steam at a pressure of 160 Ib.
is supplied by a double-ended boiler 12 ft. diam. by 16 ft. long, having
four furnaces with Farnley flues of 39 in. diam. The heating surface



280

is 2,305 sq. ft. and the grate area 78 sq. ft., while the surface condenser
exposes an area of 923 sq. ft. The screw propeller is 9 ft. diam., 13*5 ft.
pitch, and has an area of 34 sq. ft. On trial the speed was 12 9 knots, with
the engines making 120 revs, per inin., and indicating 892 h.p.

858. Drawings of engines and boilers of S.S. " City of
Dundee." (Scale 1 : 16.) Lent by Messrs. J. Howden
& Co., 1893. N. 2011.

The S.S. " City of Dundee " was built of steel at Glasgow in 1890 to the
following dimensions: Tonnage, 3,427 tons gross; length, 361 '7 ft.; beam,
42 7 ft. ; and depth, 26 4 ft.

The four drawings give the following views of the machinery : Longi-
tudinal section of the steamer, showing the engines and boilers ; cross section
of the ship, giving front view of the boilers ; cross section showing end view
of the engines ; and a horizontal section showing the engines and boilers
in plan.

The engines, by Messrs. Howden & Co., are a three- stage expansion set,
with cylinders 25 in., 42 in., and 68*5 in. diam., by 4 ft. stroke. The crank-
shaft is in two duplicate end throws joined by couplings bolted to the webs
of the intermediate crank. The crank- shaft is carried in four bearings,
of which the central pair are larger than the end ones so as to insure
uniform wear. The valves are all on the sides of the cylinders and are worked
from the connecting and piston-rods by Morton's gear (see Mechanical
Engineering Collection).

Steam at 160 Ib. pressure is supplied by two single-ended cylindrical
boilers 14*25 ft. diam. by 11 5 ft. long, each with three furnaces 42 in. diam.
Forced draught on Howden's system (see No. 913) is fitted to these boilers,
which have produced steam equivalent to 25 indicated h.p. per sq. ft.
of grate area.

859. Diagrams illustrating the arrangement of machinery
in H.M. warships. Presented by the Institution of Civil
Engineers, 1894. N. 2040.

These were prepared to illustrate a paper by Sir A. J. Durston, K.C.B.,
in 1894, and represent typical vessels built under the Naval Defence Act
of 1889.

Three views show the machinery of H.M.S. " Bamillies," a first-class,
steel-built, armoured battleship constructed at Glasgow in 1892. It is con-
tained in six watertight compartments, the engines being two independent
sets separated by a central compartment extending past the boilers and used
as a magazine, while the boilers are in two sets of four each, fired athwart-
ships. Protection is afforded by a protective deck over the engines and boilers,
also by side armour and side coal bunkers below deck.

The three views of H.M.S. " Royal Arthur," first-class, deck- protected,
wood-sheathed cruiser, built at Portsmouth in 1891, show engines arranged
as before ; but the single-ended return tube Scotch boilers are in sets
of four each, in two compartments and fired in a fore-and-aft direction ;
there is no central magazine. Protection is afforded longitudinally and
transversely by coal bunkers, by a protective deck, and by an armour coaming
round the engines. The engine platform is built up above the cellular bottom
on plate frames.

Three similar views of H.M.S. " Forte," second-class, deck-protected,
wood- sheathed cruiser, built at Chatham in 1893, shows her to be similar
to the last, the coal protection at the boilers being, however, varied slightly.

In the three views of H.M.Ss. "Onyx" and "Renard," torpedo gunboats
built at Birkenhead in 1893, the engines are shown arranged abreast in two
sets as above. The stokehold compartments are fitted forward of the engines,
and there are four locomotive wet-bottom boilers, with furnaces divided by
water spaces.



281

860. Diagrams sliowing framing of engines for warships.
Presented by the Institution of Civil Engineers, 1894.

N. 2040.

These were prepared in 1894 to illustrate a paper by Sir A. J. Durston,
K.C.B. Each frame is for a cylinder of the same size, and the weight of
the corresponding bed-plate, standards, and guides is given.

In H.M.S. " Royal Arthur " all four standards are of cast steel, bracketed
I- section, with the guides bolted to both the back and front. Weight,
47-77 tons.

In H.M.S. " Ramillies " the back standard is of cast steel box section,
forming the condenser, the guides being on the face. The front standards
are forged steel pillars. Weight, 78 08 tons.

H.M.S. " Crescent " is very similar, but has the back standard of cast
iron. Weight, 82 08 tons.

H.M.S. "Gibraltar" has all the standards of forged steel, with bracing
in two directions. Weight, 67 '2 tons.

H.M.S. " Royal Oak " has forged steel back and front pillars, diagonally
braced in two directions. Weight, 69 '77 tons.

861. Diagrams of engines and boilers of H.M.S. "Daring."
(Scale 1:2.) Contributed by Messrs. John I. Thorny croft
& Co, 1895. N. 2059.

These show one of the two sets of three- stage expansion engines fitted
to this twin-screw torpedo boat destroyer.

There are four cylinders in each set arranged in pairs, the high pressure
19 in. diam. and intermediate pressure 27 in. diam. forming one pair, and
the two low-pressure cylinders (each 27 in. diam.), the other. The cylinders
of each pair are inclined from the vertical alternately to the right and
to the left, thus enabling their axes to be brought close enough together
in a fore-and-aft direction to introduce a three-webbed crank, the central
web being common to the two cranks. The cylinders are not jacketed ;
piston valves are used on the high pressure, and flat valves on the other
three cylinders. The reciprocating parts in most cases balance one another,
small counterweights only being necessary, and but little vibration is felt.
The framing is of the light and open character common to torpedo boat
engines ; each steel column, which is a prolongation of the main bearing
bolts, is stiffened by diagonal stays secured to a continuous bed-plate, which
is attached to the main bearings. There are two air-pumps, worked by
side-levers, to each set of engines, all other pumps being independent.

Steam is supplied by three boilers of the Thornycroft water-tube type,
similar to those fitted to H.M.S. "Speedy" (see No. 902), but modified
so as to use two furnaces in each, and thus obtain a greater area of fire-
grate in the available space. Each boiler has 63 sq. ft. of grate area,
and 2,630 sq. ft. of heating surface ; the total power indicated is 4,400 h.p.,
representing 23 3 h.p. per sq. ft. of grate.

The guaranteed speed of the " Daring " was 27 knots, but during a series
of trials in June 1894, she realised at her designed displacement an average
speed of 29 2 knots ; owing to a deeper immersion necessitated by Admiralty
requirements, her official trials resulted in 27*7 knots.

862. Two-stage expansion launch engine. Made by Messrs.
W. Sissons & Co., Ltd. Received 1908. Plate X., No. 4.

N. 2464.

This shows the propelling engine of a launch or cutter, in which, as is now
almost invariably arranged, the cylinders are above the crank-shaft. The
set is of non-condensing, two-stage expansion type, with cylinders 5 5 in. and
8 in. diam. respectively, by 5 -5 in. stroke, acting on separate cranks formed
at right angles in a steel crank- shaft, the whole of which, including the



Online LibraryScience Museum (Great Britain)Catalogue of the naval and marine engineering collection in the ... museum .. → online text (page 39 of 58)