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Lincolnshire coast, was the second floating light, and was established in
1736.

These early lightships were from 80 ft. to 90 ft. in length, and from 100
to 180 tons burden ; they had one mast, nearly amidship, carrying a yard.
At the masthead was a large red flag, while at each extremity of the yard
was a lantern lighted by candles. When these candles required trimming
the yard was lowered by a winch and placed fore and aft, the rigging being
so arranged as to permit of this being easily performed. During foggy
weather a bell was sounded. They were moored with anchors and hemp
cables.

761. Built whole model of a Goodwin lightship. (Scale
1 : 24.) Lent by the Corporation of the Trinity House,
1865. N. 1087.

This represents the North Goodwin lightship, one of four stationed
around the Goodwin Sands. It exhibits three fixed white lights, at heights
of 20 ft., 25 ft., and 34 ft. respectively, and is distinguished by day by three
masthead globes ; a gong is sounded during foggy weather. It is moored
with 42 cwt. mushroom anchors and 1'5-in. chain cables.

The port side of the model shows the ship complete, while on the star-
board side the timbers, waling, cabins, oil-tanks, seamen's lockers, and other
fittings are left visible. The deck detail is also very accurately shown, the



235

hand-lead, log, and drift lines, gong, pumps, boats, guns for warning vessels
seen standing into danger, crab winches for hoisting and lowering the
lanterns, etc., being all represented to scale.

Length, 96 ft. ; breadth, 21 ft. ; depth, 10 '7 ft.

762. Whole model of the Sunk lightship. (Scale 1 : 48.)
Lent by the Telegraph Construction and Maintenance Co.,
1892. * N. 2008.

This represents a lightship moored on the Sunk shoal in the North Sea,
9 miles east of Walton-on-the-Naze. It is connected by telegraph and
telephone with the shore, so that during bad weather tugs or lifeboats may
be called out to the assistance of vessels seen to be in distress.

In 1870 an attempt was made to establish a floating telegraph station at
the entrance of the English Channel by mooring the old corvette " Brisk "
in 65 fathoms, 60 miles from Lands End. This was unsuccessful owing to
the breaking of the insulated cable through the motion of the ship.

In 1885 the " Sunk " lightship was fitted with electrical appliances for
shore communication, but the cable soon broke down. Double mooring, as
shown, was adopted to prevent the mooring chains damaging the cable, but
the failure of the electrical circuit was afterwards avoided by the use of a
helical conductor. The instruments used were the Wheatstone ABC, the
Morse sounder, and the telephone.

The model is fitted with an electric bell and an insulated cable, by which
connection is made with a battery and key outside the case and corre-
sponding with the shore end of the cable.

763. Whole model of Outer Gabbard lightship. (Scale 1 : 24.)
Lent by the Corporation of the Trinity House, 1897.

N. 2157.

This composite- built vessel was constructed at Newcastle in 1888 by
Messrs. Robert Stephenson & Co. ; her frames are of iron, the topsides of
teak, and the bottom planking of elm, sheathed with copper to a considerable
height above the water-line.

The lantern is 8 ft. diam., and contains eight two-wick Douglass lamps
with 21-in. reflectors : the illuminant used is heavy mineral oil. The light
gives a group of four white flashes at minute intervals with an intensity of
8,000 c.p. During fog a reed horn, worked by a hot-air engine, gives four
successive blasts every 45 seconds.

The vessel is moored in 16 fathoms of water, near the Gabbard Sand
off Harwich, with 210 fathoms of chain cable 1*625 in. diam., and a 3-ton
mushroom anchor.

Her crew on board consists of a master, two lamp-lighters, and four
seamen.

Length, 105 ft. ; breadth, 23 -5 ft. ; depth, 12 -8 ft.

764. Occulting light apparatus. Presented by Major-Gen.
H. P. Babbage, 1904. N. 1465.

It was in 1850-5 that the late Charles Babbage, F.B.S., introduced his
system of occulting lights for lighthouses, by which the beacon is
enabled continuously to signal its number; the mechanism shown is that
originally made for moving the screen by which the series of eclipses is
occasioned.

The apparatus consists of a train of wheels driven by a weight and
regulated by a revolving fan; this train lifts and lowers an obscuring
disc in an arbitrary manner determined by the position of notches cut in
the edge of a wheel. The arrangement shown signals the number 587
in the following way. After the light has been steadily visible for a



236

long interval five occultations take place ; then there is a short interv a
followed by eight occultations, and another short interval followed by seven
occultations, the first number following the long intervals and the others
the short ones.

The modem flashing lights usually revolve, but concentrating their
rays into several narrow beams give a flashing signal which, owing to the
concentration, has greater penetration than a steady light, as well as the
desired individuality.

765. Photographs of arrangements of lighthouse lenses.
Lent by Messrs. Chance Bros. & Co., 1875. M. 1397.

These show the optical apparatus for lights of the first, second, third
and fourth orders, both revolving and fixed; also for oil or electric
illumination.

766. Marine lamp. Presented by the U.S.A. Lighthouse
Board, 1880. N. 1541.

This oil lamp, patented by Messrs. Dennis and Wheeler in 1867-8,
was adopted by the U.S.A. Government as an anchor light giving an
all-round illumination. The protecting glass is in the form of a cylin-
drical lens, with corrugations on Fresnel's principle to give horizontal
distribution.

The lamp is regenerative in principle, the products of combustion being
used to heat the air supplied to the burner.

767. Navigation lights. Lent by Messrs. Nunn, Ridsdale
& Co., 1905. N. 2392.

Since 1863, by Intel-national Agreement, all vessels have been required
to carry a number of special lights in well-defined positions for pre-
venting collisions at sea. The Board of Trade regulations governing the
character and disposition of such lights for British ships may be thus
summarised :

All vessels when under sail, under steam, or in tow shall carry from
sunset to sunrise a green light on the starboard or right-hand side and a
red light on the port or left-hand side, each visible at a distance of 2 miles
over a horizontal arc equivalent to 10 points of the compass (112* 5 deg.),
i.e., from right-ahead to a position 2 points abaft a transverse or beam
line. A fore-and-aft screen is to be placed on the inboard side and project
3 ft. forward of each lamp, in order to prevent convergence of the two
beams. In addition a steam vessel shall carry on or in front of the fore-
mast a bright white light visible at a distance of 5 miles over an arc of
20 points of the compass (225 deg.) ; a second light of similar character
may be carried abaft this position providing it is fixed 15 ft. higher than
the foremost one.

Any vessel being overtaken by another shall show from her stem a
white light or a flare-up light, the former to be carried at the same level as
the side lights and to be visible at a distance of 1 mile over an arc of
12 points of the compass (135 deg.). A light similar to the above may be
used by a steam vessel having another vessel in tow.

A vessel at anchor, under 150 ft. in length, shall cany forward where
best seen a white light visible all-round the horizon for a distance of 1 mile ;
when over 150 ft. in length the vessel shall cariy in addition a similar light
near the stern which shall not be less than 15 ft. lower than the foremost
light.

The set of five oil lamps shown, in general features, comply with the
above regulations ; in point of size, however, they are only suitable for a
motor boat. The side lights marked " Port " and " Starboard " are fitted



with red and green glasses respectively, while those marked "Mast Head,"
" Stern" and '"Anchor" are fitted with white lenses having corrugations on
Fresnel's principle to give parallel beams of light ; all have internal
spherical reflectors. The arc of illumination is limited, except in the case
of the anchor lamp which provides an all-round light. The usual fittings
for suspending or securing the lamps are shown on each.

An adjacent sketch shows in plan and elevation the disposition of the
various lights on a steam, vessel when under way, and also indicates the
respective arcs of visibility of each, as prescribed ; the letters A.A. mark
the position of anchor lights upon a large vessel. Further details of
navigation lights and particulars relating to sound signals for fog, etc., are
shown on an adjacent printed card.

768. Model of bell buoy. (Scale 1 : 8.) Presented by the
U.S.A. Lighthouse Board, 1880. N. 1540.

This is an improved form of the early signal buoy in which the swaying
motion due to the waves caused a bell on the buoy to ring. Unfortunately
such simple appliances are silent in calm weather when fog is most
prevalent.

The arrangement shown consists of a moored buoy supporting an iron
frame in which a bell is fixed. The clapper of the bell is in the form of a
spherical shot which rests on a plate, with radial corrugations supported by
the frame ; the grooves cause the shot to strike against the bell as the buoy
swings, instead of simply rolling around within it.

769. Steam siren. Lent by Messrs. Steven and Struthers,
1887. N. 1729.

This signalling apparatus, for use at sea as a foghorn, etc., was patented
by Messrs. John Steven and Thomas Burt in 1882. It is a modification of
the instrument for the production and analysis of musical notes invented
in 1819 by Cagnard de Latour.

In the fog- siren shown steam or compressed air is, by a simple valve,
admitted into an annular casing provided with twelve vertical tangential
slots through which the fluid can issue in jets. Inside this is a cylinder
with similar slots oppositely inclined, and this cylinder is carried on a central
axis so that it can freely turn, the arrangement resembling an inward-flow
turbine except that the flow is interrupted while the wide vanes blind the
orifices.

To start the inner cylinder when the slots are not coincident, extra vanes
on the inside are provided for six jets of steam to impinge against. To
direct the sound a cowl or bell- mouth is added, which can be clamped in
any desired position.

The note sounded, depending upon the velocity of rotation of the
fan, has a changing pitch which is very characteristic of such signalling
appliances.



LIFE-SAVING APPLIANCES.

Until the 19th century vessels were usually totally unprovided
with any special arrangements for preserving the lives of those
on board in the event of the vessel sinking, and it was not till
1888 that the " Merchant Shipping Life-Saving Appliances Act "
rendered the adequate provision of such emergency fittings
compulsory.



238

in cases of foundering, the usual expedient was to construct
rafts from empty water-casks, spare spars, etc. ; but this required
time, and became increasingly difficult as the employment of
iron steamers extended. The idea, however, survives in the
special pontoons sometimes stowed along the bulwarks or
amidships, ready fitted for use, on some vessels, while in many
passenger steamers the deck seats are so constructed as to
become rafts when placed in the water.

Life-belts made of cork covered with canvas and sufficient
to float another adult besides the wearer form part of the
equipment of all passenger vessels, while similarly constructed
life-buoys of annular shape are carried on the bulwarks, bridge,
and other accessible parts of the ship. Copper life-buoys of
various forms are usually carried astern in ships of the Royal
Navy ; these are adapted for night use by fitting some system
of automatic illumination.

Life-boats are the most reliable and generally successful
means of saving shipwrecked crews ; but such appliances have
been placed in this collection with the other numerous forms
of boats.

When a vessel was wrecked on a rocky coast where a
life-boat was not available, the earliest method of establishing
connection with those on shore was by throwing a line from
the ship. In 1807, Capt. G. W. Manby, F.R.S., reversed this
by firing a grapnel with, rope attached from a mortar on shore.
Messrs. Trengrouse and Dennett, used a rocket to propel the light
line, and this idea is embodied in the apparatus adopted by the
Board of Trade in 1855, and now used at all coast stations. In
the United States Capt. D. A. Lyle's gun is used, in which
the rope is attached to the shot and is within the cartridge. In
all cases a hawser is eventually hauled on board and made
fast to the stump of a mast ; it then serves to support a
life-buoy, cradle, or life-car, by which one to seven persons
may be hauled ashore at each trip, the arrangement becoming
a form of aerial ropeway.

In the neighbourhood of steep cliffs it is customary to
provide ladders or cliff cranes for use in the event of a vessel
being driven on to the rocks at the base.



770. Photograph of model of cliff crane. Received, 1896.

N. 2099.

This shows the original crane as used by the Royal Humane Society at
Brighton in 1841. It is designed for the rescue of people wrecked in
inaccessible places, such as the base of precipitous cliffs. The crane is
drawn to the edge of the cliff, until the derrick overhangs the base, a weight
forming a counterpoise being placed at the inner end. The people are then
hoisted in a car or basket. Captain Manby's mortar apparatus was fitted
to this example.



239

771. Model of vessel's upper deck with canting bridge and
life-boat. (Scale 1 : 24.) Contributed by William Smith,

Esq., 1870. N. 1320.

This life-saving arrangement was patented by Capt. H. W. Hire, R.N.,
and Mr. J. White, of Cowes, in 1886 ; it was adopted in H.M. Indian troop-
ships and in the merchant service.

There is a see-saw bridge athwartship, rather longer than the ship's
beam, and hinged on a metal support amidships ; it is also supported at the
ends by adjustable metal stanchions. The bulwarks and stanchions are
hinged so that they can be swung outboard, thus lowering either end of the
bridge and converting it into a launching way.

The life-boat was patented by Messrs. A. Lamb and J. White in 1862 ;
it has bow, stern and side air cases and is fitted with three strong external
keels to act as launching guides. Provision is made for carrying light
guns.

772. Whole models of pontoon life-rafts. (Scale 1 : 12.)
Lent by Capt. J. W. Hurst, 1868. N. 1198-9.

This construction, patented by Capt. Hurst in 1865, consists of two
iron pontoons stayed apart diagonally by rods and formed into a raft by
cross beams secured by clamps, so that the whole can easily be put together.
There is a raised gunwale round the raft, with rowlocks for twelve oars, and
it is also fitted with masts and sails.

Length, 27 "5 ft ; breadth, 3 ft. ; depth, 3*5 ft.

A separate model shows this raft stowed as a portion of a vessel's
bulwarks.

773. Model of life-saving apparatus. (Scale 1 : 6.) Presented
by H. S. Harland, Esq., 1874. N. 1372.

Three arrangements of apparatus for saving drowning persons are
shown. They consist of coils or reels of life-lines, with cork buoys at
intervals. Capt. Ward's cork belt is part of the equipment, and enables
a man to swim out with a life-line. To be ready for use on ice the lines are
carried coiled in baskets.

774. Model of life-buoy stowage. (Scale 1 : 6.) Presented bv
H. S. Harland, Esq., 1874. N. 1371.

This method of carrying buoys was introduced by Mr. Harland in 1868
to avoid the loss of time involved in releasing a buoy that is lashed in
position. Circular buoys are placed 011 the inside of the bulwarks between
the stanchions and supported in chocks ; they are fastened in front by
simple latches.

775. Model of ship's life-boat apparatus. (Scale 1 : 12.)
Presented by R. T. Fairbridge, Esq., 1879. N. 1399.

These several appliances were introduced by Mr. Fairbridge in 1872.

The boat-lowering gear consists of a form of trip hook at each end,
fitted with lanyards for releasing from amidships.

A combined life-raft and launching slip for boats is shown, also a canvas
shoot for conveying women and children into a floating boat.

The boats are shown stowed beneath protective canvas covers.

776. Whole model of combined life-boat and raft. (Scale
1 : 12.) Presented by N. H. J. Smith, Esq., 1863. N. 926.

This arrangement was patented by Mr. G-. F. Parratt in 1852-3. The
central portion is an ordinary life-boat, but after being lowered a triangular
frame of spars is projected from each side ; these frames carry netting



240

supported by inflated india-rubber bags, which thus increases the accommo-
dation. Thwarts for the crew are provided on the rafts, rowlocks being
fitted on the projecting spars in addition to those on the gunwales.

777. Model of life-net. (Scale 1 : 12.) Presented by the
Commissioners of the 1851 Exhibition, 1874. N. 1392.

This arrangement was designed by Lieutenant R,. J. Howe, B.N., about
1874, and has the advantage of being readily improvised from ship's stores.
A triangular raft is formed of three spars supported by three barrels ; a floor
of netting is added.

778. Life-buoy. Presented by Major H. B. Rodway, 1879.

N. 1512.

This form was patented by Major Rodway in 1878. It consists of a
sealed tin-plate cylinder, 6 in. long by 4' 5 in. diain., provided with a strap,
which, when adjusted around the neck, will support a person in either a
vertical or a horizontal position ; the total weight is 1 5 Ib.



241



MARINE ENGINES.

The early methods of obtaining motive power from steam
are detailed in the Mechanical Engineering Collection (Cata-
logue, Part L). The problem of applying these results to
navigation was not solved till the weight of the boiler and
engine could be reduced within the limits of displacement of
a boat that the engine could propel at a reasonable speed.
Thus Denis Papin, in 1707, succeeded in propelling a boat by
manual labour applied to cranks, but was unable to adapt
a steam engine for the purpose. Jonathan Hulls, in. 1736.
patented a tugboat accommodating an atmospheric engine with
a ratchet-wheel mechanism for obtaining rotative motion (see
No. 779), but there is no conclusive evidence that it was tried.

Patrick Miller (b. 1731, d. 1815), who was experimenting
with double-hulled vessels fitted with paddle-wheels driven
by men turning capstans, had his attention drawn to an
engine patented in 1787, by William Symington (b. 1763,
I. 1831). A trial, in 1788, with this engine (see 'No. 783)
fitted to a pleasure boat proved completely successful,
as did also another with a larger boat and engine in the
following 3 r ear ; Miller tried, without success, to induce
Boulton and Watt to join him in this enterprise and also offered
his results to the Admiralty.

Great credit is due to Johii Fitch (b. 1743, d. 1796),
of Pennsylvania, who, after five years spent in experimenting
with different combinations of engines and propelling apparatus,
succeeded, in 1790, with a boat propelled by stern oars
in running a service between Philadelphia and Bordentown ;
it was unsuccessful, however, probably because so little space
was available for cargo and passengers.

Symington, in 1801-4, financed by Lord Dundas, produced
a thoroughly satisfactory marine engine (see No. 784). His
boat was tried with success on the Forth and Clyde Canal,
but as the proprietors feared damage to the canal banks, the
boat was disused and the scheme was not taken up elsewhere.
Meanwhile Robert Fulton (b. 1765, d. 1815), who had made
successful experiments on the Seine in 1803, ordered from
Boulton, Watt & Co. an engine which, in 1807, he fitted into
the " Clermont," thus successfully inaugurating steam navi-
gation on a commercial scale in the New World. Development
was rapid, and Fulton's unmechanical bell-crank engine was
quickly displaced by the "square" or "cross-head" engine
of John Stevens, known 011 this side of the Atlantic as the
"steeple" engine and generally credited to David Napier,
although, on land and in a slightly different form, it had long
before been used by Trevithick.

The first steamboat to run commercially in Europe was
Henry Bell's "Comet" of 1812; his engine was of the half
beam type (see No. 787). The influence of the then standard
beam construction is further visible in the marine engine

U 6773.



242

developed by Boulton, Watt & Co. prior to 1820. This was
the side-lever engine (see No. 794) which remained the
standard type till about 1860, having been brought to great
perfection by Clyde engineers, and having given rise to minor
varieties (see Nos. 797-8). This influence also appears in the
" walking-beam " engine developed about 1813 for the shallow-
draught American river steamers, for which it has not yet been
quite displaced ; its structural details give a peculiarly striking
effect to these enormous steamers (see No. 818).

The steeple engine introduced into this country about 1842
by David Napier was an improvement on the side-lever in that
it occupied less space and had fewer parts. As the crank-shaft
was usually hung just over the cylinder, two or more piston
rods were necessary (see Nos. 803-4), but other arrangements
were also used.

Murdock's oscillating engine of 1785 had been applied to
marine work as early as 1822 in the " Aaron Manby," but it
was not till 1827, when Joseph Maudslay equipped it with an
efficient valve gear (see No. 811) that the saving in space di(|
to the absence of connecting rods, was appreciated, and it was
only when re-introduced in 1838 by John Penn, of Greenwich,
that the type became and has since continued to be such a
favourite for paddle steamers.

The practical introduction in 1836 of the screw for propulsion
necessitated a higher speed of rotation of the propeller shaft than
of the paddle-wheel. At first, this need was met by employing
engines of the accepted slow-running type and gearing up to
the propeller shaft by ropes, belts, and pitch chains (see No. 820).
When John Ericsson, who brought out his screw in 1836,
employed a direct-acting engine to propel it, its speed was
considered unsafe. The introduction of the screw also gave a
great impetus to the application of steam to the propulsion of
warships and as the machinery was required to be below the
water-line, a horizontal type of engine was developed. Ericsson
tried one or two remarkable types (see No. 835), and finally
adopted the return connecting-rod type, which was really only
the steeple engine placed horizontally. This was first fitted, by
his representative, in the French frigate " Pomone " followed in
1844 by H.M.S. " Amphion" ; it remained the standard type of
engine in H.M. Navy down to 1876 (see No. 849). Another
type extensively used for the same purpose during the same
period, was Penn's trunk engine ; when first introduced for
paddle propiilsion it found but little favour, but it was revived
with success in 1847 for screw propulsion (see No. 845). The
horizontal direct-acting type was extensively adopted between
1860 and 1885, but was always adversely criticised on account
of the shortness of the connecting rods possible in the athwart-
ship space available (see No. 850).

For the mercantile marine the inverted or steam hammer
type has been in favour for screw propulsion since 1860. In
the increased space available, consequent on the introduction



243

about 1885 of the protective deck, it became possible to use this
type in warships also and it was exclusively so fitted till the
introduction of the steam turbine. With it, a number of
cylinders can be placed tandem in order to get successive
stages of expansion rendering a desired crank arrangement easy
(see No. 852). Its economy in athwartship space admits, con-
veniently, of double sets for twin screws. For paddle steamers,
now confined to river and estuary services, the oscillating
engine, which does not readily lend itself to compounding, has
given way to the diagonal direct-acting engine (see No. 819)
and this type is also displacing the " walking-beam " type in
American waters.

The successful introduction into marine practice by Messrs.
Randolph, Elder & Co. of compound working in the S.S.
: ' Valparaiso " and " Inca " (1856) was of vital importance in
the direction of reducing the consumption of fuel, although as
their steam was only at 25 Ib. pressure, corresponding to



Online LibraryScience Museum (Great Britain)Catalogue of the naval and marine engineering collection in the ... museum .. → online text (page 33 of 58)