NTR DERMARIO PONTOON DOO "
Year: 1875

page_text: LETTERS PATENT to Dirk Arnold Wittop Koning, of 58, Hugo de
Groot Straat, Rotterdam, in the Kingdom of Holland, for the In-
NTR DERMARIO PONTOON DOO "
PROVISIONAL SPECIFICATION left by the said Dirk Arnold Wittop
Koning at the Office of the Commissioners of Patents, with his
Petition, on the 17th April 1875.
I, DIRK ARNOLD WITTOP KONING, of 58, Hugo de Groot Straat,
Rotterdam, in the Kingdom of Holland, do hereby declare the nature
of the said Invention for "A NEW OR IMPROVED PNEUMATIC PONTOON DOCK,"
to be as follows:-
==
My Invention relates to that class of floating or pontoon docks in
which the water admitted into the pontoon for effecting its submergence
is ejected therefrom when required by means of compressed air.
The chief objects of the Invention are, economizing the power
required to raise the dock and ship; securing the proper amount of

page_text: stability and buoyancy, economy of material in the construction, and
facility of operation.
I employ an arrangement of pontoons and other air and water
chambers of the following character
First. A principal pontoon or chamber, preferably of a closed rect-
angular box-like form, constructed of sufficient dimensions and strength
to carry its own weight, that of the other air and water chambers, and of
the ship to be raised. I prefer to construct this principal pontoon with a
scries of lattice or plate cross girders of a depth equal to that of the said
pontoon, these cross girders serving to support the ceiling, bottom, and
side walls of the pontoon, other vertical girders being arranged to support
and stiffen the end walls. I also provide a strong keel girder extending
from end to end of the pontoon, and situated in the middle of its width.
This keel girder is intended to support the kecl blocks for the reception
of the ship to be docked. The principal pontoon is subdivided by par-
titions into separate chambers or compartments, the disposition, number,
and dimensions of such chambers or compartments being determined by
calculations having reference to the size and weight of the largest ship
the dock is intended to raise and support, and also to the stability of the
dock when floating and when submerged. Certain of the compartments
into which the principal pontoon is divided are provided with discharge
valves, operated by suitable means, through which the water is ejected
by the pneumatic pressure. The other compartments by preference are
not provided with discharge valves, but are connected with the compart-
ments containing them by means of tubes, the lower ends of such tubes
being connected to the bottoms of the first compartments or set of
compartments, and the upper ends of such tubes with the tops of the
compartment or set of compartments next in order, and so on, until the
compartment or compartments containing the discharge valves is or are
reached. Air pipes leading from the air compressing machinery enter S
the top of the first compartment or set of compartments, and air being
forced thereinto the water is first expelled therefrom, and then succes-
sively from each compartment or set of compartments next in order,
being forced through the tubes into the next compartment or set of
compartments, finally escaping through the discharge valves in the last 3
compartment or set of compartments. I prefer to arrange a compart-
ment on each side of the principal pontoon, with separate discharge
valves and air pipes distinct from those above described; such compart-

page_text: ments can then be used as reserves of floating power, buoyancy, or
stability, as may be required.
Second. On the top of the principal pontoon, one at each side, and
over the ceiling thereof are formed two air-tight chambers, extending by
preference the full length of the said principal pontoon. These air-tight
chambers are not intended to contain water, and are preferably con-
structed of dimensions sufficient to give buoyancy equal or nearly equal
to supporting the whole weight of the principal pontoon. They assist
in maintaining the stability of the dock, whether wholly or partly sub-
merged. They may also be used as reservoirs for the compressed air to
be used in ejecting the water.
Third. When the depth of water available is sufficient to permit of
such an arrangement the end walls of the principal pontoon are carried
up above the ceiling thereof, so as to form with the inner side of the
air-tight chambers last above-mentioned a water-tight basin, in which
the ship to be raised is placed, and shored up or supported on the keel
blocks in the usual manner. By the employment of this basin as soon
as the dock and ship upon it are raised sufficiently to bring the edge of
the said basin above the level of the water, which can be effected by
emptying some only of the compartments of the principal pontoon, the
water contained in the said basin can then be emptied therefrom into
certain of the compartments of the principal pontoon, preferably into
those arranged at or near cach side thereof, whereby additional stability
will be given to the dock, and the ship will be laid dry, although not
actually raised above the level of the water outside the basin. By this
means a considerable saving of power and labour is effected in cases
where only temporary or partial repairs are required to be effected.
Fourth. Over each of the aforesaid air-tight chambers is constructed
a water-tight chamber, extending by preference over the full length
of the said air-tight chambers, and of a width and depth suited to the
purposes they are intended to fulfil. Those purposes are the following :-
First, they may be made to assist in the submergence of the dock by
having water let into them; second, they may be made to counter-
balance any misplacement of the ship on the principal pontoon by
having water let out of certain of the subdivisions or compartments into
which they are divided until the dock is brought level, notwithstanding
any lateral or longitudinal misplacement of the ship with regard to the

page_text: centre line of the dock, or with regard to its centre of length. These
water-tight chambers are provided with suitable valves or cocks for
running the water out of any particular compartment as may be
required.
In cases where by reason of insufficient depth of water the end walls
of the basin cannot be employed, or where for other reasons it becomes
necessary to raise the ship entirely above the level of the water, it is
only necessary to continue the ejection of the water from the compart-
ments of the principal pontoon until the latter with its load is raised to
the required height.
Suitable valves and apparatus for working them must be provided for
admitting water into the principal pontoon to effect the necessary degree
of submergence to allow of its passing under the bottom of the ship to
be docked.
The engines and pumps for supplying the compressed air to the com-
partments of the principal pontoon or to the air-tight chambers are by
preference carried in small vessels or lighters attending the pontoon
dock, being connected therewith by means of flexible or articulated
pipes.
As it is sometimes necessary to repair the discharge valves in the
compartments, or for other purposes to enter the latter whilst they
contain compressed air, I employ an arrangement of double man-holes,
whereby entrance can be effected at any time, whether the pressure of
air is on or off.
SPECIFICATION in pursuance of the conditions of the Letters Patent,
filed by the said Dirk Arnold Wittop Koning in the Great Seal
Patent Office on the 16th October 1875.
TO ALL TO WHOM THESE PRESENTS SHALL COME, I, DIRK
ARNOLD WITTOP KONING, of 58, Hugo de Groot Straat, Rotterdam, in
the Kingdom of Holland, send greeting.
WHEREAS Her most Excellent Majesty Queen Victoria, by Her
Letters Patent, bearing date the Seventeenth day of April, in the year of
our Lord One thousand eight hundred and seventy-five, in the thirty-

page_text: eighth year of Her reign, did, for Herself, Her heirs and successors, give
and grant unto me, the said Dirk Arnold Wittop Koning, Her special
license, that I, the said Dirk Arnold Wittop Koning, my executors, ad-
ministrators, and assigns, or such others as I, the said Dirk Arnold
3 Wittop Koning, my executors, administrators, and assigns, should at any
time agree with, and no others, from time to time and at all times
thereafter 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 "A NEW OR IMPROVED PNEUMATIC PONTOON DOCK," upon the condition
(amongst others) that I, the said Dirk Arnold Wittop Koning, my exe-
cutors or administrators, by an instrument in writing under my, or their,
or one of their hands and seals, 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 month's next and immediately after the date
of the said Letters Patent.
NOW KNOW YE, that I, the said Dirk Arnold Wittop Koning, do
hereby declare the nature of the said Invention, and in what manner the
same is to be performed, to be particularly described and ascertained
in and by the following statement thereof, reference being had to the
accompanying Sheets of Drawings, and to the letters and figures marked
thereon, that is to say :-
My Invention relates to that class of floating or pontoon docks in
which the water admitted into the pontoon for effecting its submergence
is ejected therefrom when required by means of compressed air.
The chief objects of the Invention arc economizing the power
required to raise the dock and ship, securing the proper amount of
stability and buoyancy, economy of material in the construction, and
facility of operation.
I employ an arrangement of pontoons and other air and water
chambers of the following character.,
First. A principal pontoon or chamber preferably of a closed
rectangular box-like form constructed of sufficient dimensions and
strength to carry its own weight, that of the other air and water
chambers and of the ship to be raised. I prefer to construct this
principal pontoon with a series of lattice or plate cross girders of a depth

page_text: equal to that of the said pontoon, these cross girders serving to support
the ceiling, bottom, and side walls of the pontoon, other vertical girders
being arranged to support and stiffen the end walls. I also provide a
strong keel girder extending from end to end of the pontoon, and
situated in the middle of its width. This keel girder is intended to
support the keel blocks for the reception of the ship to be docked. The
principal pontoon is subdivided by partitions into separate chambers
or compartments, the disposition, number, and dimensions of such
chambers or compartments being determined by calculations having
reference to the size and weight of the largest ship the dock is intended
to raise and support, and also to the stability of the dock when floating
and when submerged. Certain of the compartments into which the
principal pontoon is divided are provided with discharge valves, operated
by suitable means through which the water is ejected by the pneumatic
pressure. The other compartments by preference are not provided with
discharge valves, but are connected with the compartments containing
them by means of tubes, the lower ends of such tubes being connected
to the bottoms of the first compartment or set of compartments, and the
upper ends of such tubes with the tops of the compartment or set of
compartments, next in order, and so on until the compartment or com-
partments containing the discharge valves is or are reached. Air pipes
leading from the air compressing machinery enter the top of the first
compartment or set of compartments, and air being forced thercinto the
water is first expelled therefrom, and then successively from each com-
partment or set of compartments next in order being forced through the
tubes into the next compartment or set of compartments, finally
escaping through the discharge valves in the last compartment or set of
compartments. I prefer to arrange a compartment on each side of the
principal pontoon with separate discharge valves and air pipes distinct
from those above described, such compartments can then be used as
reserves of floating power, buoyancy, or stability, as may be required.
Second. On the top of the principal pontoon one at each side and
over the ceiling thereof, are formed two air-tight chambers extending by
preference the full length of the said principal pontoon. These air-tight
chambers are not intended to contain water, and are preferably con-
structed of dimensions sufficient to give buoyancy equal or nearly equal
to supporting the whole weight of the principal pontoon. They assist in
maintaining the stability of the dock, whether wholly or partially sub-

page_text: merged. They may also be used as reservoirs for the compressed air to
be used in ejecting the water.
Third. When the depth of water available is sufficient to permit of
such an arrangement, the end walls of the principal pontoon are carried
up above the ceiling thereof, so as to form with the inner sido of the air-
tight chambers last above mentioned a water-tight basin in which tho
ship to bo raised is placed, and shored up or supported on the keel
blocks in the usual manner. By the employment of this basin as soon
as the dock and ship upon it are raised sufficiently to bring the edge of
the said basin above the level of the water, which can be effected by
emptying some only of the compartments of the principal pontoon, the
water contained in the said basin can then be emptied therefrom into
certain of the compartments of the principal pontoon, preferably into
those arranged at or near cach side thereof, whereby additional stability
will be given to the dock, and the ship will be laid dry although not
actually raised above the level of the water outside the basin. By this
means a considerable saving of power and labour is effected in cases
where only temporary or partial repairs are required to be effected.
Fourth. Over each of the aforesaid air-tight chambers is constructed
a water-tight chamber extending, by preference, over the full length of
the said air-tight chambers, and of a width and depth suited to the
purposes they are intended to fulfil. Those purposes are the following:-
First, they may be made to assist in the submergence of the dock by
having water let into them; second, they may be made to counter-
balance any misplacement of the ship on the principal pontoon by having
water let out of certain of the subdivisions or compartments into which
they are divided, until the dock is brought level notwithstanding any
lateral or longitudinal misplacement of the ship with regard to the
centre line of the dock or with regard to its centre of length. These
water-tight chambers are provided with suitable valves or cocks for
running the water out. of any particular compartment, as may be
required.
In cases where by reason of insufficient depth of water the end
walls of the basin cannot be employed, or where for other reasons it
becomes necessary to raise the ship entirely above the level of the water
it is only necessary to continue the ejection of the water from the com-
partments of the principal pontoon until the latter with its load is raised
to the required height.

page_text: carried up above the ceiling thereof, and the ceiling of the said principal
pontoon which forms the bottom of such basin.
Fourthly. Of two water-tight chambers A, A, extending one over
each air-tight chamber B, B, from end to end thercof.
The Drawings illustrate a pneumatic pontoon dock designed to raise
and support ships weighing up to 7,000 tons, and for this purpose the
principal pontoon may be about 380 feet in length, by 85 feet wide, and
12 feet in height. These dimensions may of course be varied according
to the weight and shape of the largest ship intended to be raised by the
dock. The principal chamber is arranged so as to be partly or entirely
filled with water, whereby it may be sunk below the water level to the
depth necessary to allow the ship to enter the apace between the sido
chambers A, B, and A, B. The chambers B, B, do not contain water,
but act as air chambers to secure sufficient buoyancy to maintain the
dock floating when the principal chamber is submerged. The
chambers A, A, serve to contain water for the purpose of compensating
for any possible deviation of the centre of gravity of the ship from tho
central point of the dock, as will be hereafter described.
Arrangements also hereafter to be described enable the water to be
ejected from the principal pontoon in order to give sufficient floating
power to raise the dock and ship to the required extent.
Thesc
In order to give sufficient strength to the principal pontoon a series of
lattice or plate cross girders k, k, are employed, which in the present
examples are placed at distances apart of about 3 ft. 3 ins.
girders serve to support the ceiling, bottom, and side walls of the pontoon.
Other vertical girders 1, 1, see Fig. 3, serving to support and stiffen the
end walls. m is the keel girder for supporting the keel blocks on which
the ship rests when docked, and n, n, are girders to receive the thrust
of the shores employed in supporting the vessel in an upright position
when docked.
In the example which the Drawings are intended to illustrate the
principal pontoon is, by preference, subdivided into separate chambers or
compartments in the manner and in the proportions shown in the
Drawings, and specially figured in the diagrams 4 and 5, but it will be
understood generally that the disposition, number, and dimensons of
such subdivisions must be determined by calculations having reference

page_text: to the size and weight of the largest ship the dock is intended to raise
and support, and also to the stability of the dock.
The bottoms of the compartments E, E, of the principal pontoon are
provided with discharge valves a, a, which may be constructed and
operated in any convenient manner, but by preference opening inwards
towards the chambers E, E, and pressed against their seatings by
weighted levers, screws, or otherwise when required to be closed. The
mechanism for operating them should be arranged so as to be worked
from the tops of the chambers A, A, which are provided with platforms
and hand railings for the convenience of the operator.
The other compartments D, G, H, I, and K are by preference not
provided with discharge valves, but are connected one with the other
and with the compartments E, E, by means of tubes 1, 2, 3, 4, and 5,
the lower ends of which are connected respectively to the bottoms of the
compartments G, H, I, K, and D, and the upper ends with the tops of the
compartments H, I, K, D, and E. Air pipes leading from the air com-
pressing machinery enter the tops of the compartments G, and air being
forced thereinto the pressure exerted upon the surface of the water
therein forces it through pipe 1 into the compartment H; thence by the
pipe 2 into the compartment I, and so on by the pipes 3, 4, & 5 through
the compartments K and D into E, whence it is finally ejected by the
discharge valves a, a; thus the compartments G are first emptied, and
then successively those marked H, I, K, D, and E.
The compartments F, F, are not connected with the other com-
partments, but have in their bottoms separate discharge valves b, b, and 1
are also provided with separate air pipes leading from the chambers B, B.
These chambers F, F, are only used when, after having emptied the
basin Las hereafter explained, it becomes necessary for some reason to
raise the dock and its load as high as possible out of water. They can
thus be used as reserves either of floating power, buoyancy, or stability,
as may be required; or in cases where on account of the shallowness of
the water the dock cannot be sunk deep enough to allow of the end walls
of the basin L being used to their full depth, or at all, they may be
subdivided, and one or more subdivisions thereof united to the other
divisions of the principal pontoon, so as to act along with them in pro- 3
ducing sufficient floating power to lay the ship dry without employing
the basin L.

page_text: When the depth of water is sufficient to enable the basin L to be
employed it is utilized in the following manner:-As soon as the dock
and ship upon it are raised by the ejection of the water more or less
from the compartments G, H, I, K, D, and E of the principal pontoon
sufficiently to bring the edge of the end walls of the said basin above the
level of the water the water contained in the basin L is allowed to flow
therefrom into the compartments E, E, by means of the pipes d, d,
which lead from the bottom of the said basin L to the said compart-
ments E, E. The upper ends of such pipes are provided with valves c, c,
for allowing or preventing the flow of water from the basin L into the
compartments E, E, as may be desired. By this means the ship may be
laid dry, although not necessarily raised above the level of the water
outside the basin. The transference of the mass of water from the
basin L to the two compartments E, E, at the sides of the principal
pontoon gives additional stability to the dock and its load, and in cases
where only temporary or partial repairs are required a considerable
saving of power and labour is effected by the fact of the dock and its
load not requiring to be raised so high as would be necessary were the
basin not employed. Should the compartments E, E, not be of sufficient
capacity to contain all the water from the basin L the surplus will flow
over into the compartments D, D, by means of the pipes 5, 5, as soon as
compartments E, E, are filled, and the surplus from D, D, into K by the
pipes 4, 4, as soon as D, D, are filled, and so on into the other com-
partments. The end walls of the basin L may also be provided with
valves or cocks for running the water out of the said basin direct into
the sea or other water surrounding the dock, when the said basin L is
raised above the surface of the said surrounding water.
Instead of the basin L a separate pontoon may be employed, on which
a ship may be raised by the pneumatic pontoon dock and then floated
away to enable other ships to be raised in a similar manner.
The water-tight chambers A, A, are as above explained intended,
firstly, to assist in the submergence of the dock by having water let into
them by means of the taps or valves p, p, as the dock sinks; and,
secondly, to counterbalance any lateral or longitudinal misplacement of
the ship on the principal pontoon, and for this purpose each of the said
chambers A, A, are subdivided into three compartments by partitions q, q,
rising from the bottom to or near to the top of such chambers, that is to
say, cach chamber is divided into one middle and two end compartments.

page_text: The end compartments are employed to counterbalance any longitudinal
misplacement of the ship by allowing as much water to run out of the
two end compartments, which are situated at that end of the dock
towards which the misplacement has taken place, as will compensate for
the excess of weight on that side of the centre of the length of the dock
due to the said longitudinal misplacement. The middle compartments
are employed to counterbalance any lateral misplacement of the ship by
allowing as much water to run out of the compartment situated on the
side towards which the misplacement has taken place as will compensate
for the excess of weight on that side of the centre line of the dock due
to the said lateral misplacement. The valves or cocks p, p, employed
for letting the water into the compartments of the chambers A may also
be employed for running the water out of such of them as may be
necessary in order to effect the above-mentioned compensation as quickly
as possible, and thereby to preserve the dock level as it rises with its
These valves or cocks are by preference arranged at various
heights, as shown, in order to allow of their being brought into action as
the dock rises in order to let the water out of the compartments, for the
purpose of effecting the compensation as described.
load.
The articulated or flexible pipes for supplying the compressed air to
the pontoon are shown at i, i, the air compressing machinery being by
preference carried as before explained in small vessels or lighters. The
pipes i, i, are shewn connected to the air-tight chambers B, B, suitable
valves or cocks being provided in the bottoms of the latter to allow of
the compressed air passing from them into the compartments G, G, or
F, F; or if preferred the said pipes i, i, may as before explained be
connected directly to the said compartments G, G, or F, F.
In order to obtain access to the compartments suitable man-holes are
provided in the ceilings, as at g, and if necessary in the partitions
between cach compartment, and as access to the chambers E-and F may
sometimes be necessary in order to repair the discharge valves even
when the pontoon is immersed, and the compartments still contain
compressed air, the following arrangement of double man-holes and air
sluice is employed, whereby entrance can be effected at any time,
whether the pressure of air is on or off:- is a water-tight tube passing
through from top to bottom of the chamber A, and containing a ladder,
by which access can be obtained to the man-hole in the ceiling of
chamber B. is an air-tight compartment forming an air sluice in the

page_text: chamber B, at the bottom of which are the man-holes * and * leading
respectively to the compartments E and F; or if preferred the com-
partment h³ may be dispensed with, and the entire chamber B used as
the air sluice.
By entering the compartment and closing the man-hole ', which
is by preference hinged in such a manner as to admit of its being closed
and fastened from the compartment h², the man-holes h³ or h* may be
removed at will, and access thus obtained to E or F, the escape of com-
pressed air therefrom being confined to what will fill the sluice
chamber h or chamber B, as tho case may be.
The chambers E and F or either of them may be emptied of water at
any time by forcing air direct into them and opening the discharge
valves, all the other compartments remaining full of water if desired,
and it will be readily understood that while a valve is being repaired
the compressed air will prevent the water from entering the chamber.
By the arrangement of principal pontoon above described every part
from which water has to be expelled by means of the compressed air
remains constantly submerged until the ship has been totally raised,
whereby the whole of the buoyancy produced by the expulsion of the
water continues to contribute to the lifting power, an effect which does
not occur in those floating docks wherein portions from which water
has been expelled are raised above the level of the water outside.
By the disposition of the compartments of the principal chamber in
the manner described the surface of water to be acted upon by the air
at the commencement of the operation of lifting is small, but on account
of the great immersion the tension of the air is high.
As the operation progresses the surface of water acted upon increases,
whilst on account of the decreased immersion the tension of the air
becomes less, and hence the working power exerted and speed of lifting
are comparatively regular throughout the operation.
The immersion of the dock may be effected either by letting water
run into the basin L, and thence by the valves c and pipes ḍ into the
compartments E, from whence it will flow into D, and so on into K, I,
H, and G by the pipes 5, 4, 3, 2, & 1; or the discharge valves a, a, in
the compartments E may be opened and water admitted thereby, or
both methods may be employed at once. Whichever method be

page_text: manner in which the same is to or may be carried into effect, I would
have it understood that what I claim as my Invention is,-
First. The pneumatic pontoon dock consisting of a principal pontoon
or chamber for developing the necessary lifting power, two air-tight
chambers for securing the buoyancy of the whole dock when the
principal pontoon is immersed, and two water chambers for counter-
balancing any misplacement of the centre of gravity of the ship on the
dock, constructed, arranged, and operated substantially as herein-before
described and illustrated in the Drawings.
Second. The method of subdividing the principal pontoon into
separate compartments, connected together by pipes so as to be emptied
of or filled with water successively, substantially in the manner hercin-
before described and illustrated in the Drawings.
Third. The use in pneumatic pontoon docks of the basin L with the
valves and pipes connected therewith, whereby the water contained in
it may be run into the compartments of the principal pontoon, as and
for the purposes described.
Fourth. The employment in pneumatic pontoon docks of the water
balancing chambers A, A, as and for the purposes described.
Fifth. The application and use in pneumatic pontoon docks of the
system of double man-holes and air sluice herein-before described and
illustrated in the Drawings for obtaining access to the chambers E and
F notwithstanding the presence of compressed air in such chambers.
In witness whereof, I, the said Dirk Arnold Wittop Koning, havo
hercunto set my hand and seal, this Eleventh day of October,
in the year of our Lord One thousand eight hundred and seventy-
uve.
DIRK ARNOLD WITTOP KONING. (L.S.)
Patentee.