Improvements in Tank Ships or Boats.
Year: 1892

page_text: Date of Application, 19th Aug., 1892
Complete Specification Left, 17th June, 1893-Accepted, 22nd July, 1893
PROVISIONAL SPECIFICATION.
Improvements in Tank Ships or Boats.
I, ALEXANDER MCDOUGALL, a citizen of the United States of America, and
residing at Duluth, in the County of St. Louis,, and State of Minnesota, one of the
United States aforesaid, Ship Builder, do hereby declare the nature of this
invention to be as follows:-
66
My present invention relates to various new and useful improvements in vessels,
for carrying oil, naphtha, and other liquid cargoes in bulk, in which are adopted the
same general charateristics of hull and construction heretofore invented by me.
Heretofore I have illustrated two distinct classes of vessels, known particularly as
barges" and "steam-boats," which are to be constructed of steel or iron plates,
riveted or otherwise secured to transverse ribs, which extend continuously around
the interior of the hull, so as to thereby form a very strong and rigid construction.
Both of the said varieties of vessels embody the same general shape of hull, having
straight parallel sides, a covered top, a rounded bottom, a spoonshaped bow, and a
skeged stern, to facilitate steering.
In the present vessel, having a particular object in view, certain changes and
additions are made to better fit the boat to that particular object, as I shall explain
more fully hereinafter. The hold of the boat is separated from the bow and stern
portions, which, in a steam boat, contain the boilers and engines, by a double
partition or bulkhead, having water therein, to prevent leakage of oil into such bow
and stern portions. The said hold is provided with a longitudinal bulkhead,
extending from one of said extreme double partitions to the other, and with
cross-bulkheads, running from side to side, whereby the hold of the boat will be
divided up into series of tanks or compartments, in which the oil or other liquid
cargo is to be pumped or otherwise forced in the ordinary way. The improved
vessel is provided also with a peculiar arrangement of piping at the lower portions
of said tanks or compartments connecting with a suitable steam pump placed either
in the bow or stern portions, and by which the oil or other liquid may be pumped
out of the same, whereby the vessel can be unloaded, quickly and economically.
On the top or deck of the vessel, are placed suitable expansion tanks, which
communicate with the main tanks or compartments within the hold of the boat, to
allow for the usual expansion of the oil or other liquid under varying degrees
of temperature. Such expansion tanks may be each centrally located over two of
the main tanks or compartments, so as to provide for the expansion of the oil
therein, or there may be an expansion tank situated over the point of intersection of
the longitudinal bulkhead with the cross-bulkheads whereby each of the said
expansion tanks serves a similar purpose for four of the said main tanks.or
compartments, as will be evident. By making use of the said expansion tanks, the
main tanks or compartments of the vessel can be always kept entirely full, whereby
the danger of the oil or other liquid moving back and forth therein, under the
influence of the pitching and rolling of the vessel is obviated. The improved vessel
is also provided with suitable man-holes for reaching the interior of the main oil
tanks or compartments, and with appropriate vents to allow for the escape of all
gases which may be evolved from the oil, and with other features and improve-
ments as will increase its usefulness, and improve its efficiency for the purpose
intended.
For a better comprehension of my invention attention is directed to the
accompanying drawings, forming a part of this Specification, and in which:
Figure 1, is a longitudinal sectional view of an improved oil barge.

page_text: ectional viewj
Figure 4, a side elevation of a steam boat, adapted for the carrying of oil or other
liquid cargo, and
.
Figure 5, an enlarged section of a modified wedge bow.
In all of the above views, corresponding parts are designated by the same letters
of reference.
The boat illustrated in Figure 1, 2 and 3, is similar in many respects to the
improved barge invented by me, being constructed of metal plates; secured to
transverse frames, and having straight sides, parallel with each other both
horizontally and vertically, an arched or curved top, a bottom rounded at the
corners, a spoon-shaped bow, and a skeged stern, to facilitate steering.
By making the hull of this particular design in this manner, without sheer
or unnecessary superstructure, it may be built very economically and there will be
a maximum of strength and a minimum of weight whereby the vessel is enabled to
carry a larger cargo than ordinary boats of the same size. The particular
advantage of a spoon-shaped bow, as I have before pointed out, is that it can be
manufactured much cheaper and will tow better and more easily than an ordinary
wedge-shape or cut away bow. A vessel having a hull such as I have described,
without sheer, is, of special adaptability for the transportation of oil and liquids
which being level will fill up all the available space beneath the decks, so that
there will be no air spaces formed above the oil. The presence of such air, spaces
is objectionable, for the reason that space is uselessly taken up, which might be
otherwise availed of, and, is dangerous as it will allow the oil to move bodily back
and forth and from side to side when the boat is pitching and rolling.
A. are double partitions which separate the hold of the vessel from the bow and
stern portions thereof, and the said double partitions are to be filled with water so
that any oil which may leak into the same will float on the water therein.
B. is a longitudinal bulkhead which extends, in the present boat, from one double
partition (A) to the other. The lower edge of this longitudinal bulkhead forms
a tight joint with the keelson to which it is riveted or otherwise secured, and the
upper portion of the said longitudinal bulkhead is similarly attached to the top of
the vessel.
Owing to the great strength which the bulkhead (B) will impart to the vessel in
a longitudinal direction, it may be advisable to dispense with a keelson, since the
said bulkhead (B) will serve in its stead, and in which case the lower edge of the
said longitudinal bulkhead is to be riveted or bolted. to the inside of the bottom of
the boat.
It is to be understood; that the said, longitudinal bulkheads may extend the entire
length of the vessel, fore and aft, and that it may be advantageously applied to
ordinary vessels for imparting longitudinal strength to the same.
"C. C. are cross-bulkheads, which extend from side to side and from the top to the
bottom of the hull, so as to divide the same transversely. By means, of the
longitudinal, bulkhead and the cross-bulkheads, the interior or hold, of the vessel
will be divided into a number of tanks or compartments arranged side by side, for
carrying the oil, naptha or other liquid cargo in bulk.
In the present vessel the usual water bottom, is dispensed with, since, the tanks or
compartments within the hold will prevent the same, from filling, in case the, bottom
becomes accidentally, stove in, and by thus dispensing with the said water, bottom,
the carrying capacity of the boat will be materially increased.
D. D. are expansion tanks, made perfectly cylindrical in form, of a proper
capacity to allow for the ordinary expansion of the oil and, connecting with the
hold. The said expansion tanks are centrally arranged on the deck of the, vessel,
either between, the cross-bulkheads (C) or, directly over the same., In, the first
place each of the said expansion tanks, serves for two of the tanks or compartments
in the hold, and in the latter, case, each of the said expansion, tanks serves for
four of such compartments as will be understood. Each expansion tank is provided
preferably with two hatches in its top hinged as shown, and adapted to be fastened
"

page_text: down when desired by set screws or bolts in the usual way. Each of the said
hatches leads into the tank or tanks directly beneath, which can be reached in this
way for cleaning and for other purposes. Each expansion tank is also provided
with a suitable vent (a) through which all gases which may be evolved from the
oil, may be allowed to escape. In the bottom part of the boat, on each side of
the longitudinal bulkheads is a heavy metal pipe (E) which connects at its forward
or rear end with a suitable steam pump (F) operated from any available source of
steam supply. Extending down from the said pipes (E) at suitable points, are
shorter pipes (F) having bell shaped or flared mouths located close to the bottom
of the vessel, so that all oil can be pumped out of the tanks by the pump (F).
The pipes (E) are provided with valves (G) therein, preferably at the point of
intersection with the shorter pipes (F) so that when any one or more of said valves
is operated the oil may be pumped out of any particular tank or tanks. The said
valves are to be operated by suitable rods (6) which may extend up through the
expansion tanks or elsewhere.
The vessel illustrated in Figure 4 is similar in most respects with the oil barge
just described, except that it is provided with a boiler and engine in the stern
portion, behind the aft double partition (A) and with a large cabin supported on
turrets as I have before described. The arrangement of the oil tanks, bulkheads,
expansion tanks and pipes, is the same in the steam boat as in the barge. If it is
so desired, a passage way may be supported on the expansion tanks, extending fore
and aft, whereby the officers and crew of the vessel may pass in safety from one
end of the boat to the other, without the danger of being swept overboard by any
waves which may pass over the deck in heavy weather. It is also to be understood
that the said expansion tanks may be also used to support masts which are to
carry sails.
Dated this Fifth day of May A.D. 1892.
COMPLETE SPECIFICATION.
Improvements in Tank Ships or Boats.
I, ALEXANDER MCDOUGALL, a citizen of the United States of North America,
residing at Duluth, in the County of St. Louis, and State of Minnesota, one of
said United States aforesaid, Ship Builder, do hereby declare the nature of this
invention and in what manner the same is to be performed to be particularly
described and ascertained in and by the following statement and accompanying
drawings
The improved vessel is adapted for use in carrying oil, naptha or other liquid
cargoes in bulk, and may either be towed by a tug or other steamer, or may be
provided with suitable boilers, engines and a propeller or propellers so as to be
independent of such towing steamer. The principal requisites of a good'oil boat is
to provide a vessel wherein the oil may be so confined as to prevent any possibility,
of the oil moving back and forth or from side to side, under the influence of the
motions of the vessel, for such a motion would damage, if not burst the tanks to
make proper provisions to allow for the expansion and contraction of the oil, naptha
or other liquid cargo, under the influences of heat and cold; to provide means
whereby the tanks may be easily filled, emptied, inspected and ventilated; to
positively protect the oil etc., from leaking, either into the engine room, cabins, or
entirely free of the boat: to allow of means for the escape of any gases which
might be generated from the oil or similar cargo; and to prevent the entrance of
such gas into the boiler rooms, or other places where a fire is burning.
The improved vessel which I have invented for carrying oil, naptha or other
liquid cargoes in bulk, in either form to be described hereafter, has all the
requirements above set out.
$1
The principal novelties in the construction of my improved vessel is a hull of

page_text: pcculiar construction having a curved.top and bottom, straight sides; a spoon
shaped or wedge bow and a skeaged stern. This hull is without sheer, and the
bottom, except at the extreme bow, is built on a straight horizontal line. By
making the hull without sheer it is especially adapted for carrying liquid cargoes
which must necessarily be level. The hold is divided off from the bow and stern
portions by a double partition which contains water, and which will prevent the
escape of any oil or gas in the bow or stern portion." Within the bow portion is
the forecastle, below which is a water tank.
Within the stern portion or the after cabins, and, if the vessel is a propeller, the
coal bunkers, boilers, engines etc., are placed within the stern portion directly aft
of the said double partition.
Near the bow is a turret, which supports a small working deck, upon which are
placed the capstan, windlass and other gear for properly handling the anchor
chains, hawsers and tow line. In case the boat is to be towed a similar turret
supporting a working deck is placed near the stern. This after working deck
carries the steering wheel, and a suitable capstan.
The forecastle and after cabins are reached through these turrets by means of a
suitable staircase or ladder in each turret.
If the vessel is provided with independent propelling mechanism, then there are
two or three turrets near the stern which support a large and commodious cabin
containing accommodations for the officers, engineers, passengers, etc.
Beneath the after cabin in the stern of the vessel is a water tank, which corre-
sponds with the water tank in the bow.
The vessel may be provided with an inner or false bottom, and the space between
said inner or false bottom and the true bottom of the boat is what I call a water
bottom. This water bottom, together with the tanks at the bow and stern, are to
be filled with water, so as to properly ballast the vessel when light or when partially
loaded. A part of the cargo may be stowed within the water botton or instead
water may be kept continually within the water bottom, which will then serve the
purpose of a water bulk-head similar to those above described for dividing the
hold from the bow and stern portions and which will prevent the leakage of any
oil into the water bottom. The said inner or false bottom may be dispensed with.
The space formed between the fore and aft water bulk-heads, and above the
inner or false bottom, if used, or above the bottom of the vessel, if not used,
constitutes the hold of the boat, into which the cargo is pumped or otherwise
introduced. This hold is divided lengthwise by means of a suitable longitudinal
bulkhead which extends up from the inner or false bottom, or from the bottom of
the vessel, to the underside of the top or deck of the vessel and the hold is divided,
crosswise by a number of shorter bulk-heads extending from each side of the
vessel to the longitudinal bulkheads at the centre. These various bulkheads are
to be secured in place by means of suitable angle irons to also prevent leakage.
By means of these longitudinal and cross bulk-heads I divide the hold of the vessel
into a number of tanks for the reception of the oil, naphtha or other liquid cargo.
It is necessary to make use of these tanks in order that oils or liquids of varying
character may be carried, and in order that only a part of the tanks may be filled
when it is impossible to get a full cargo. Extending up from the top or deck of
the vessel are a number of well known expansion chambers. Each expansion
chamber is arranged directly over the central longitudinal bulkhead so that each
expansion chamber communicates with two oil tanks. In this manner I obtain an
oil vessel having one half as many expansion chambers as there are oil tanks. It
might be possible to arrange chambers of somewhat larger size over alternate
cross bulk-heads so that one expansion chamber will answer for four oil tanks.
Each expansion chamber is provided with a suitable opening in its top to enable
a hose or pipe to be inserted therein to fill the tanks. The said opening is to be
closed and bolted down tightly when at sea.
The confined air which is within the oil tank is allowed to escape through one or
more valves or vents placed on each expansion chamber. The valves or vents also
'

page_text: allow any gas or vapour to escape from the oil tanks. Each oil tank is provided
with a hatch, opening into its upper end and through which the tank may be
cleaned, ventilated or inspected. These batches are provided with a rubber or
elastic packing underneath and are to be bolted down, so that there can be no
leakage of oil or gas from the tanks. Within each oil tank and resting upon the
horizontal frames of the boat in a suitable cradle I prefer to place a sinall
cylindrical auxiliary tank holding about 700 gallons in ordinary boats. When
the vessel is to have a comparatively light draft, say about 14 feet on a length of
280 feet, the main oil tanks only are filled. On such a light draft there will be
considerable free board to be effected by the waves, but the small cylindrical
auxiliary tanks before referred to, containing air, will prevent any material rolling
in the boat, as they will give a certain amount of buoyancy at each side which will
prevent the sides from being submerged. If it is possible to have a deeper load-
line, then two or more of these cylindrical tanks are filled, in pairs side by side,
so as not to effect the stability of the boat. It will be observed that as more and
more of these cylindrical auxiliary tanks are filled, the stability of the vessel will
be increased owing to the greater draft, so that a correspondingly smaller number
of the empty tanks will be required to prevent any rolling. In this way, it will
be understood, the cylindrical auxiliary tanks whether full or empty, will greatly
increase the stability of the vessel.
A narrow platform or walk extends from the front turret to the after turret, or
in the case of a propeller, to the after cabin, and rests upon and is supported by
the tops of the expansion chambers. This platform or walk will enable the crew
to pass from one turret to the other with the utmost safety from the effects of the
sea, and to operate the valves or vents in the expansion chamber and to handle
the loading pipes. It is to be mentioned. however, that both the auxiliary
cylindrical tanks and the platform or walk above referred to, may be dispensed
with, without detriment to the successful operation of the vessel.
Almost all of the explosions which have occurred on oil vessels have been caused
by the ignition of the gases which are left in the tanks after the oil has been
removed. I propose to remove these gases by blowing air in at the lower part of
each tank through the pipes which are used for filling the water bottom with water
and for removing the same. This air will fill the various tanks and the gases
being lighter will escape through the valves or vents in the expansion chambers.
For a clearer comprehension of my invention as I have outlined above, attention
is directed to the accompanying drawings forming a part of this Specification and
in which:
Figure 1. is a longitudinal sectional view, partly in elevation, of the preferred
form of oil steamboat, showing the cylindrical auxiliary tanks, the water bottom,
and the platform or walk.
Figure 2. a cross sectional view of the same.
Figure 3. a side view of an oil barge, showing the platform or walk thereon.
Figure 4. a top plan view of oil barge, with the elevated platform or walk and
the auxiliary tanks removed, and
Figure 5. a side elevation of an oil steamboat, of the same form,
Figure 6. a sectional view of Figure 4.
In all of the above views corresponding parts are designated by identical letters
of reference.
The frame-work of this hull consists of a number of transverse ribs, extending
entirely around the same and strengthened longitudinally by the usual keelson and
by a number of braces and plates.
There are also a number of braces which extend crosswise in the hull and also
vertically, which tend to further strengthen the hull.
B is the forecastle and C is the after cabin, which are reached by the turrets D
and E respectively.
In the case of an oil steam boat there are preferably three turrets F F F near

page_text: the stern which support a large cabin containing accommodation for the officers,
passengers etc., as shown in Figure 1.
ان
The boilers and engines are placed in the stern portion of the vessel.
G is a working deck, which is mounted on the forward turret and in the case of
a tow boat also on the after turret. On these turrets are placed the usual capstan,
windlass and the steering wheel.
H is an inner of false bottom, placed some distance above the true bottom, and
the space between the two form a water bottom. The said inner or false bottom
may be dispensed with.
I is a water tank which is placed in the bow of the boat, and a corresponding
water tank is placed in the stern.
J are water bulkheads which divide the hold from the bow and stern portions.
Each of the water bulkheads is composed of two metallic partitions placed a short
distance apart and filled in with water. This will prevent any oil or naptha from
leaking into the bow or stern portion, since any oil which may pass by the first
partitions will float immediately to the top of the water between the two partitions.
As a matter of fact, however, it is thought that no oil will leak past the first
partition, since the water in the bulkheads, being heavier, will tend to force it
back.
K is a bulkhead which extends from the forward water bulkhead to the after
water bulkhead, and from the inner or false bottom, if used, to the underside of the
top or deck of the vessel, so as to divide the hold of the vessel into two longitudinal
sections. If a water bottom is not used, said bulkheads extend from the bottom
proper to the top of the hull.
LL are cross bulkheads which extend from the central longitudinal bulkhead out'
against the sides of the vessel.
These bulkheads K and L will divide the hold of the vessel into a number of
compartments or tanks for the reception of the oil; naptha or other liquid cargo in
bulk.
M M are a number of expansion chambers which extend up from the deck of the
vessel, and which are arranged over the central longitudinal' bulkhead. Each
expansion chamber connects with two oil tanks so that a certain number of expan-
sion chambers may answer for double that number of oil tanks. The expansion
chambers are provided with a small manhole in the upper end through which the
usual pipes may be passed for filling the oil tanks. These manholes are to be closed
by a suitably packed cover or hatch when at sea. The expansion chambers are
each of a sufficient capacity to allow of the usual expansion of oil, which is about
1% for each twenty degrees of temperature, and are provided with suitable valves
or vents to allow the air to escape from the tanks when they are being filled. These
valves or vents also allow any gas to escape from the tanks.
NN are-hatchways opening into each tank and adapted to be covered by hatches
which are provided with a rubber packing underneath, and which are to be bolted
into position. These hatchways allow each oil tank to be inspected, cleaned and
ventilated.
O is a platform or walk shown in Figure 1, 2 and 3, and extending from the
forward turret to the rear turret, resting on the top of the expansion chambers and
provided with a suitable railing. This platform offers a safe passage from one
turret to the other turret and allows the various valves or vents to be easily
reached. The various hatches N N may be handled in any suitable way from this
platform.
P are the cylindrical auxiliary tanks before referred to. Each of these tanks P
is to be placed in a separate oil tank and is supported by a suitable cradle as shown
in Figure 2, which rests upon and is secured to the cross beams in the boat. The
objects of these auxiliary tanks have been before pointed out.
The oil tanks communicate with the water bottom, if a false bottom is used, by
means of suitable openings, passing through the inner or false bottom. Said

page_text: openings are to be provided with valves so that water cannot enter the tanks,
unless it is so desired when the vessel is light and carries water in her water
bottom.
The oil, naptha or other liquid cargo is pumped into the oil tanks and into the
auxiliary tanks in any suitable way, either by a pump on the dock or on the vessel
itself.
Water is pumped in and out of the water tanks and water bottom by means of
one or more pumps on the vessel.
After the oil as been removed from the tanks a considerable quantity of gas is
generally left behind, which when accidentally lighted causes almost all of the
explosions on oil boats.
I will remove this gas by connecting a fan with the water
pipes of the boat, and air is to be forced down into the water bottom and from
thence will pass into the oil tank so as to force all the gas out of the same.
When a water bottom is not used, air may be forced directly into the oil tanks
for the same purpose.
Having now particularly described and ascertained the nature of my said inven-
tion, and in what manner the same is to be performed, I declare that what I
claim is: .
First: As an improvement in oil boats, a hull, having a rounded top or deck,
said hull being divided into oil tanks, by means of longitudinal and cross-bulkheads,
substantially as described.
Second: As an improvement in oil boats, a hull, having a rounded top or deck,
said hull being divided into oil tanks, by means of longitudinal and cross-bulkheads,
and provided with expansion tanks, on said top or deck, communicating with said
oil tanks, substantially as described.
Third As an improvement in oil boats, a hull, having a rounded top or deck,
said hull being divided into oil tanks, by means of longitudinal and cross-bulkheads;
and provided with expansion tanks on said top or deck, communicating with said
oil tanks, and with a platform or walk on said expansion tanks, substantially as
described.
Fourth As an improvement in oil boats, a hull, having a rounded top or deck,
said hull being divided into oil tanks by means of longitudinal and cross-bulkheads
and auxiliary cylindrical tanks in said oil tanks, substantially as described.
Dated this Twenty-third day of May A.D. 1893.
E. K. DUTTON & Co.,
5, John Dalton Street, Manchester, Agents.