IMPROVEMENTS IN MACHINERY FOR TOWING BY FIXED ROPES
Year: 1874

page_text: LETTERS PATENT to David Greig and Max Eyth, both of the Steam
Plough Works, Leeds, in the County of York, for the Invention of
PROVISIONAL SPECIFICATION left by the said David Greig and
Max Eyth at the Office of the Commissioners of Patents, with
their Petition, on the 10th February 1874.
We, DAVID GREIG and MAX EYTH, both of the Steam Plough Works,
Leeds, in the County of York, do hereby declare the nature of the said
Invention for "IMPROVEMENTS IN MACHINERY FOR TOWING BY FIXED ROPES,"
to be as follows:
―:
The present method of towing by a fixed wire rope on rivers and
canals consists in laying down from end to end of the line which has to be
worked a cable fixed at the two extremities. On the tug boat an engine
turns a clip pulley, round which the wire rope takes about half a turn,
so that the tug works itself along the stationary wire rope which is only

page_text: lifted out of the water during the passage of the vessel, and falls back
again to the bottom of the canal as soon as the tug has passed.
On ordinary rivers and comparatively deep and straight canals it is
found that though the rope is displaced by the pull of the tug whilst
nearing a bend, the steering power of the vessel is sufficiently great
to replace it into its original position. There are several serious
disadvantages in connection with this process. This however is not all,
for on shallow canals and rivers it is found that the steering power of
ordinary tugs is not large enough to pull the displaced rope back again
into its proper position. Thus after a few trips the tugs are no longer
able to keep to the centre of the water course, the rope in the curve
becoming so tight that the tug cannot press it out into its proper
place.
The improvements now to be described are intended to overcome
these difficulties. They refer partly to the machinery on board the tug,
partly to the attachment of the wire rope in curves of very extreme
description. The tug carries an engine and boiler in a compartment on
one side of the centre line of the boat, so that the rope can pass freely
over the middle of the vessel. The deck of this portion is very low,
being still further cut down towards the bow and the stern. The rope
passes first over a swinging pulley which is suspended by a universal
joint, and thus able to place itself in the proper position indicated by
the rope whatever angle the same may assume.
It then runs straight
to the clip drum round which it takes half a turn. From here it passes
backwards towards a sliding sheave round which it again takes half a
turn; this sheave is slightly inclined. The rope passes away towards a
final swinging pulley over the top of the clip drum, and falls back into
the water after having passed over the swinging pulley. The clip drum
is set in motion by means of bevel and spur wheels from the engine. The
sliding sheave turns on a stud forged to a plate provided with sliding
pieces or rollers, and thus able to move readily along a pair of rails fixed
to the deck. This plate and stud are attached to a chain which itself is
fixed to a chain drum, the turning of which moves of course the sheave
either towards or away from the clip drum, thus either diminishing or
increasing the amount of rope contained between the sheave and clip
pulley.
The chain drum forms one of the main parts of the slack gear. This
apparatus consists also of a pipe or steam cylinder open at one end, the

page_text: other end closed by a piston, and in direct communication with the
steam space of the boiler. The piston rod forms a toothed rack which
works a small pinion keyed to the same shaft which carries the chain
drum. Thus the pressure of the steam has a constant tendency to turn
the chain drum, and moves the sliding sheave away from the clip drum;
in other words it places a certain strain on the wire rope between the
clip drum and sliding sheave. Whenever this portion of the rope
becomes slack the sheave will begin to move outward, taking up the
slack; whenever it becomes too tight, it will push the sheave back, turning
the piston also against the pressure in the slack gear cylinder.
The action of the slack gear can be stopped whenever the engine is
reversed. This is done by a pawl catch acting on corresponding teeth in
the chain drum, and thrown in or out by the action of the reversing
lever of the engine.
For a tug working equally backwards and forwards on the rope
without being turned, the clip drum is placed into the middle of the boat,
two inclined sliding pullies being provided on each side of it. The rope
passes over the deck in the following manner :-It first goes over a front
swinging pulley, ther und the clip drum, then backwards round the
first sliding pulley, which is so far inclined that the rope is now held up
considerably above the clip drum; from this it passes round the second
sliding pulley; from here back again round a sheave on the top of the
clip drum, and finally over the last swinging pulley by which it leaves
the boat.
The two sliding pullies may be worked either by two separate slack
gear cylinders or by one only which acts on two chain drums connected
by differential gear, so as at any moment to bring the same amount of
strain on both sheaves.
Instead of steam pressure the slack gear can be worked by water
pressure, weights, springs, or any other suitable means, whilst the
arrangement of the clip drum and sheaves can be varied in many
ways.
For more acute curves it may still be desirable not to leave the rope
free to move entirely to the inside of the bend, but to attach it whilst
permitting the passage of tugs without interruption of the journey. For
this purpose the towing rope is attached to a chain or rope anchored on
the canal bank by means of a hook, or by a pulley whose flanges act in a

page_text: similar way to a hook. The boat itself is provided with two rails
running along its sides and with arms which are attached to the rail in
that side of the tug where the anchor and chain of the hook is fixed
which has to be passed. These arms, by the peculiar form of their ends
catch the hook, whilst the boat proceeds lifting it off the rope. The
hook then slides along the rail and over the second arm by which it is
again brought over the back rope which it takes hold of when the tug
has passed."
Another arrangement which is not entirely self-acting may be
employed in very sharp curves. The rope is ordinarily held by a hook
attached to a chain which is wound up by a chain drum, and a return
chain passes at the bottom of the canal across to the other side, and
from there round a pulley back again to the hook; thus by turning the
chain drum either way the hook can be made to slide at the bottom of
the canal either way from one side to the other. The hook lays in this
case with its point upwards a position which is maintained by its peculiar
shape, and is provided with an elongation to which a second chain or
rope is attached. Whilst the towing wire rope is held by the hook and
the tug is approaching it will produce a considerable strain on the first
chain, whilst the second chain is gently tightened by hand and fastened
to a hook on the frame of the winch.
. When the tug has arrived close up to the hook the chain drum up to
now held by a catch is allowed to revolve, and all the strain on the first
chain is at once thrown on the second chain. This, in consequence of
the place where the two chains are fixed on the hooks, will at once cause
the hook to upset and to release the towing rope. Whilst the tug is
passing a boy in charge of the winch works the hook by the return chain
first across the channel, and then slowly back again. By this latter
movement the hook is again caused to catch the towing cable which has
in the meantime fallen down again to the bottom of the channel, and
the towing cable is thus fixed in its previous position.
Instead of being released by the action of the boy at the winch the
towing cable may be knocked off the hook by a projection attached to
the tug. Thus the continuous length of the rope is not interrupted and
the tug is able to pass the point of attachment without an interruption
of its journey.

page_text: The Invention applies to all towing machinery where a fixed submerged
rope or chain is employed, by whatever contrivance the engine acts on
the said rope or chain.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said David Greig and Max Eyth in the Great Seal
Patent Office on the 8th August 1874.
TO ALL TO WHOM THESE PRESENTS SHALL COME, we, DAVID
GREIG and MAX ЕYTH, both of the Steam Plough Works, Leeds, in the
County of York, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Tenth day of February, in the year
of our Lord One thousand eight hundred and seventy-four, in the thirty-
seventh year of Her reign, did, for Herself, Her heirs and successors,
give and grant unto me, the said David Greig and Max Eyth, Her
special license that I, the said David Greig and Max Eyth, my
executors, administrators, and assigns, or such others as I, the
said David Greig and Max Eyth, my executors, administrators, and
assigns, should at any time agree with, and no others, from time to
time and at all times thercafter during the term therein expressed,
should and lawfully might make, use, exercise, and vend, within the
United Kingdom of Great Britain and Ireland, the Channel Islands,
and Isle of Man, an Invention for “IMPROVEMENTS IN MACHINERY FOR
TOWING BY FIXED ROPES," upon the condition (amongst others) that I,
the said David Greig and Max Eyth, my executors or administrators,
by an instrument in writing under our or their hands and seals, or under
the hand and seal of one of us or them, should particularly describe and
ascertain the nature of the said Invention, and in what manner the
same was to be performed, and cause the same to be filed in the Great
Seal Patent Office within six calendar months next and immediately
after the date of the said Letters Patent.
NOW KNOW YE, that I, the said Max Eyth, on behalf of myself and
the said David Greig, do hereby declare the nature of the said Inven-
tion, and in what manner the same is to be performed, to be particularly

page_text: described and ascertained in and by the following statement thereof,
that is to say :—.
-
The present method of towing by a fixed wire rope on rivers and
canals consists in laying down from end to end of the line which has to
be worked a cable fixed at the two extremities. On the tug boat an
engine turns a clip pulley, round which the wire rope takes about half a
turn, so that the tug works itself along the stationary wire rope, which
is only lifted out of the water during the passage of the vessel, and falls
back again to the bottom of the canal as soon as the tug has passed.
On ordinary rivers and comparatively deep and straight canals it is
found that though the rope is displaced by the pull of the tug whilst
nearing a bend, the steering power of the vessel is sufficiently great to
replace it into its original position, the action being somewhat as
follows: When the tug has arrived at some considerable distance yet
from the bend the wire rope is pulled towards the inside of the curve, and
the slack rope thus obtained running through the machinery falls back
into the water, perhaps several hundred yards from the bend. Arriving
in the curve itself, and following the now displaced rope, the tug would
be pressed towards the inside shore, but by its steering power it is made
to follow the centre line of the channel, and by doing so pulls the rope
from behind back again into its old position.
There are several serious disadvantages connected with this process.
The slack rope passing through the machinery is liable to kink and get
entangled on its way through guide pulleys and guards. To get rid of it
as quick as possible the clip drum has to be placed on the side of the
boat, and the rope cannot be led over the centre line of the vessel.
Even after falling down to the bottom of the channel the danger of the
rope kinking is always very great when nearing strong bends, and a
constant source of trouble. When rounding the curve itself the strain
on the back rope becomes sometimes enormous, and greatly interferes
with the free steering of the tug; but on shallow canals and rivers it is
found that the steering power of ordinary tugs is not large enough to
pull the displaced rope back again into its proper position; thus, after a
few trips the tugs are no longer able to keep to the centre of the water-
course, the rope in the curve becoming so tight that the tug cannot press
it out into its proper place.
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page_text: space of the boiler. The piston and piston rod are cast in one piece, the
latter forming a toothed rack, which works a small pinion keyed to the
same shaft which carries the chain drum. Thus the pressure of the
steam has a constant tendency to turn the chain drum and to move the
sliding sheave B away from the clip drum. In other words it places a
certain strain on the wire rope between clip drum and sliding sheave.
Whenever this portion of the rope becomes slack the sheave will begin
to move outward, taking up the slack; whenever it becomes too tight it
will push the sheave back, turning the piston also against the pressure
in the slack gear cylinder.
The action of the slack gear can be stopped whenever the engine is
reversed, which is done by a pawl catch e acting on corresponding teeth
in the chain drum and thrown in or out by the action of the reversing
lever of the engine.
Figures 4 and 5 shew an arrangement of a tug working equally back-
wards and forwards on the rope without being turned. Here the clip
drum A is placed into the middle of the boat, two inclined sliding
pullies being provided on each side of it. The rope passes over the deck
in the following manner:-It first goes over the front swinging pulley
E³, then round the clip drum A, then backwards round the first sliding
pulley, which is so far inclined that the rope is now held up considerably
above the clip drum. From this it passes round the second sliding
pulley from here back again round a sheave A¹ on the top of the clip
drum, and finally over the last swinging pulley, by which it leaves the
boat.
The two sliding pulleys may be worked either by two separate slack
gear cylinders or by one only, which acts on two chain drums connected
by a differential gear (as used in traction engines or as "jack in the box"
spinning machinery) so as at any moment to bring the same amount of
strain on both sheaves.
Instead of steam pressure the slack gear can be worked by water or
other fluid pressure, or by springs in a similar manner to that herein-
before described; the arrangement of the clip drum and sheaves can also
be varied in many ways.
In more acute curves it may still be desirable not to let the rope free
to move entirely to the inside of the bend, but to attach it whilst per-
mitting the passage of tugs without interruption of the journey.

page_text: Having thus described the nature of our Invention, and the manner
of performing the same, we would have it understood that we claim as
our improvement in machinery for towing by fixed ropes, -
1. The employment of a moveable sheave or sheaves acted upon by
steam or other fluid pressure, or by springs, substantially in the manner t
herein described, so as to take up the slack rope pulled in by the clip
drum, and to pay it out whenever the strain in the back rope becomes
greater than desirable.
2. The combined arrangements of towing machinery, substantially as
herein described and illustrated in the annexed Drawings.
3. The attachment in curves and sharp bends of the water course of
the towing rope in such a manner that the continuous length of the rope
is not interrupted, and that the tug is able to pass the point of attach-
ment without an interruption of its journey.
This Invention applies to all towing machinery where a fixed sub- 1
merged rope or chain is employed by whatever contrivance the engine
acts on the said rope or chain.
In witness whereof, I, the said Max Eyth, have hereunto set my
hand and seal, this Third day of August, in the year of our
Lord One thousand eight hundred and seventy-four.
MAX EYTH. (L.S.)