Iron screw steamer Liverpool Screw, designed by John Grantham,
of Mather & Dixon, Liverpool, 1842; 42 tons, 65 x 12.5 x 3.75ft, screw,
direct coupling to 20 hp engines by builders. Intended for use as a
tug, especially for the Mersey & Irwell Navigation.
Reported
as sold to Henry Southan of Gloucester in 1846, and renamed
Clara, for use towing. Advertised for sale by him in 1853.
Listed in MNL (ON 12345) up to 1870, as 34nrt, 24hp, owned H Southam,
registered Gloucester.
One of the first screw steamers built on Merseyside, was the Robert
F. Stockton, built for Captain Stockton, of the American Navy. She was
launched on 7th July 1838 by Laird's of Birkenhead. Earlier
experiments had also taken place on canals - using screws operated by
man-power. The first screw steam tug was the experimental iron vessel,
Liverpool Screw, designed with engines by John Grantham and a propeller
design by Woodcroft.
The main disadvantage of paddles was that as a vessel rolled,
the paddles were inefficient - either too deep or two shallow. Another
disadvantage of paddles, particularly relevant for canal use, was the
extra width required, combined with the damage caused by the wash to
the banks.
One of the advantages of paddle propulsion, and a reason that screw
propulsion was slow to take over, was the relative ease with which
ropes, and other obstructions, could be removed from the paddles, and
the relatively easy option to uncouple (lift or remove the paddle
blades) the paddles and to continue under sail, if the engine failed.
Another factor was that paddle engines typically rotated at 20-30 rpm. This was
too slow for screw propellors, so gearing was needed.
Grantham's development was to use an engine with a higher rate of
rotation (95 rpm), and with a large diameter, and large pitch, screw - enabling
both direct drive (no gears) and the possibility to free the propellor
of debris since it was partly out of the water. A screw develops side
thrust, but Grantham claimed this was not a serious impediment.
[from Chester Chronicle - Friday 26 May 1843]:
THE SCREW PROPELLER. We recently published a description of a small
iron vessel, called the "Liverpool Screw," built by Messrs Mather,
Dixon, and Grantham, and worked by a screw. At our request the
builders have furnished us with further particulars of her dimensions
and power, which answer the inquiries of a correspondent in our last.
The vessel is 65 feet between perpendiculars, and 12 feet 6 inches
beam; her average draft of water when ready for work is 3 feet 9
inches; she is worked by two cylinders of 13 inches diameter, and 18
inches stroke, and, when light, averages about 85 revolutions per
minute. The boiler is on the locomotive principle, and the usual
pressure of the steam is 50lbs. per square inch, and is sometimes
increased to 56lbs. Expansion valves are always used, which cut off
the steam at one-fourth of the stroke - thus by making allowance for
the pressure in the blast pipe, and for the operation of the
expansion, which withdraws the steam at closing, the actual power is
equal only to a boiler pressure of from 27lbs. to 30lbs. per square
inch.
In comparing this with the nominal horse-power of the vessels
against which she has been running, which generally have a pressure of
7lbs. per square inch on the boiler, and 13 lbs. in a condenser,
(equal to boiler pressure of 20lbs.) and the piston working 200 feet
per minute, makes the power employed in the screw vessel from 19 to 21
horses.
We may add a few particulars of the trip made by her on Friday last,
which was taken in order to test her power of towing. Mr. Pendlebury,
agent for the Duke's, Captain Foulkes, manager of the Duke's steamers,
and other gentlemen interested in the carrying trade, accompanied her. She
was matched against the Bridgewater, one of the best towboats on the river
for her power. The "Screw" had five flats, and the Bridgewater, seven.
The nominal power of the former is 20, and of latter, 34 horses.
With these respective loads, the screw boat occupied 1 hour and 47
minutes from the Duke's Dock to the Dock at Runcorn, beating the
Bridgewater by a few minutes, shewing a superiority in the screw of about
25 per cent in proportion to the nominal horse-power. But has since
been found from actual measurement that the respective power was 163
to 300, shewing still greater advantage for the screw.
The little vessel, in a short time after her arrival at Runcorn,
started for Weston Point. In the canals it is found the screw has not
the least effect on the banks, and that the disturbance in the water
is no more than if the same vessel is tracked by horses. At Weston
Point, the canal being deep, the steamer could make more speed than is
usually thought advisable in other places. She, however, look a flat
in tow for nearly half the distance; and with this incumbrance, and
the engine working slowly, she performed four miles in 36 minutes. An
engineer belonging to the navigation accompanied her and expressed
himself satisfied that no injury to the banks could be caused by her.
She
then proceeded at full speed up the winding and beautiful River
(Weaver), and arrived, after a most delightful sail, at Northwich. Here
she took on board a large party, and proceeded to Winsford, but owing to
the numerous narrow turns in the river, her speed could be not maintained.
The next morning she returned to Weston Point, running the distance from
Northwich in two hours and twenty-five minutes, including the delays in
the locks.
From this, she started for Liverpool, the wind blowing very
strongly against her, and the river very rough. Shortly after she
overtook the Alice tow-boat, of 70 horse-power, with three flats in
tow, one heavy, and two light. Our little vessel took the loaded flat
in tow, and now commenced a struggle. The short and angry sea
continually breaking over the flats, and almost hiding them from the
crew of the steamers; and here, more than ever, the superiority of the
screw was shewn. In spite of the state of the water and the plunging
of the vessels, it maintained its usual uniform speed, and soon left
the Alice in the distance. On reaching Liverpool she again proceeded
on her way and ran down the channel some miles, but as the tide was
falling, the water became smooth, and she therefore, returned to her
moorings.
When she left the Duke's Dock on Friday, she had 18 cwt. of coke
and 4cwt. coal on board, to this was added 11.5 cwt. of coke at
Northwich; and with this fuel she performed all the work above
described, and when she came to anchor at 3:30 p.m. on Saturday, she
had about 7 cwt. remaining. The steam was up from 7a.m. Friday till
8:30p.m. The fires were kept up all night and at 6 am. on Saturday she
again got up steam and continued till 3:30p.m. The quantity of fuel
consumed was consequently very small.
Thus, under all the circumstances in which steamer can be tested,
(says our informers,) has this little vessel proved the advantage of
the principle on which her machinery is constructed. We are informed
that same principle may be applied to vessels of the larger class,
with low-pressure engines, and without employing spur-wheels or
straps, or any of the complicated machinery which has hitherto
obstructed the progress of this important improvement steam
navigation.
[from Gore's Liverpool General Advertiser - Thursday 01 June 1843]:
THE SCREW Vessel. The spirited directors of the Steam-tug Company,
with other gentlemen, left the George's Pier-head on Friday morning,
at ten o'clock, in the Liverpool Screw, for the purpose of witnessing her
performance. The Mona, the fastest sailer of the tug vessels, kept
company as well as she could during the trip. The vessels were first
taken up the river, and various experiments in turning, stopping, and
reversing were tried. They then directed their course down the New
Channel. When in smooth water, the Mona was nearly a match for the
little screw; but, as it became rougher, the superiority the latter
became very apparent. The directors declared themselves to be well
satisfied with the results, and expressed a desire to see the vessel
dry, to examine her bottom, for which purpose she was laid ashore on
the Cheshire side, on Saturday, at low water.
Report of a trial visit to the Dee in July 1843.
[from Proc. Inst. Civil Eng., 1844, by John Grantham, February 13, 1844.]:
"Account of some experiments on a vessel called the
Liverpool Screw, fitted with Grantham's engines and Woodcroft's
screw propeller."
The Liverpool Screw, upon which the experiments, described in
this paper, were tried, is a small iron vessel 65 feet long by 12 feet
6 inches beam, and 3 feet 9 inches draught of water. She is propelled
by two high-pressure oscillating engines, with cylinders of 13 inches
diameter and 18 inches length of stroke. The steam, which varies from
56 lbs. to 60 lbs. pressure in the boiler, is admitted to the piston
for one-fourth the length of the stroke, the remainder working by
expansion. The nominal power was 20 horses, but the effective power
rarely exceeded 18.5 horses. The cylinders are placed diagonally, at
right angles to each other, and work to one crank upon the main
driving shaft, which runs direct to the propeller without gearing or
bands. The propeller, which makes 95 revolutions per minute, is on
Woodcroft's plan, with a pitch expanding from 10 to 11 feet; after
being enlarged at three several times, from 3 feet 10 inches diameter,
it is now 5 feet 4 inches diameter by 20 inches long; it is of wrought
iron, and consists of four short arms, whose united area is equal to
16 square feet; of this, only about 13 feet are immersed, a portion of
the upper side being constantly above the water: the angle of the
centre of the floats is 45° and about 40° at the periphery.
The author then gives the details of a number of
experiments, and he states that, although the proportions of the
vessel were not favourable for speed, her length being only five times
the beam, and the sectional displacement 28 [square] feet, the speed was
greater than that of all the steamers on the Mersey, except the large
sea-going steam vessels.
That the slip of the propeller, when tried by Massey's log, was
less than five per cent. That the action of the screw across the way
of the vessel, did not appear to affect the steering, or have the
slightest tendency to turn the head of the vessel.
The author is of opinion, that engineers in
general, fearing a loss might take place from lateral action, with a
long pitch, and that the steering would be affected if the propeller
was not immersed, have made the propellers too small, and that the
short pitch, which had rendered a high velocity necessary, was
detrimental. Several satisfactory experiments, in towing vessels, are
also mentioned, and it is stated that in a heavy sea, the
superiority of the screw propeller was very visible.
[from Monmouthshire Merlin - Saturday 22 December 1849]:
A STEAMER RUN DOWN. About 3 o'clock on Wednesday morning week, the Clara
steamer, while on her passage from Bristol to Gloucester, was run down
in the Bristol river by the Phoenix steamer, bound from Carmarthen to
Bristol. The Clara, which is the smaller vessel, was struck on the bows,
and the shock was so great, that the Clara was cut down to the water's
edge; but being constructed of iron, the water was admitted only into
the fore comparimants, and, by the buoyancy of the other water-tight
compartments, she was prevented from sinking, and was able to get hack
to Bristol. The master of the Clara, who ran forward just before the
collision, was much hurt; but we believe, not dangerously. The Clara
carried a light in her head, and it is stated that the Phoenix mistook
the bow of the Clara for the stern of a rival vessel going to Bristol,
and in attempting to pass, tbe collision occurred.
[excerpt from The Cardiff and Merthyr Guardian Glamorgan Monmouth and Brecon
Gazette, 30th July 1853]:
TO STEAM-PACKET COMPANIES AND SHIP-OWNERS. MESSRS. BARNARD, THOMAS, AND
CO. have received directions from the Trustees to SELL by AUCTION, at
the ALBION TAVERN, near the Docks, GLOUCESTER, on WEDNESDAY, August
10th, 1853.
The Screw Steamer
"CLARA," Burthen 70 Tons. Both Vessels steam fast, are fitted with
excellent Engines and Boilers, equal to a pressure of 60lbs. to the
inch.
The Sale will commence punctually at Three o'clock. The
Vessels may he viewed in the Canal, and the Boiler at Messrs. Danks,
Venn, and Sanders's, the Docks, Gloucester. For all further
particulars apply to Mr. HENRY SOUTHAN, Jun., Docks, Gloucester;