US2314555A - Tanker - Google Patents

Description

March 23, 1943. J. PREUss l2,314,555

ATTY

J. PREUSS March 23, 1943.

TANKER v Filed July 13, 1942 2 Sheets-Sheet 2 FIG.3

INVENT OR.

JOHN PR EUSS Patented Mar. 23, 1943 UNITED STATES PATENT OFFICE TANKER John Preuss, Memphis, Tenn.

Application July 13, 1942, Serial N0. 450,678

8` Claims.

This invention relates to new and useful improvements in vessels, particularly of the type adapted for the transportation of liquids, usually known as tanker-barges, which have iiat bottoms throughout the major portion of their Width and length. The major diiliculties in liquid transportation in tanker-barges of known types have arisen through the difficulty of thoroughly and eiciently emptying the vessel of its cargo at its destination with the consequence that the empty vessels are returned with a substantial amount of the cargo still on board. This residual cargo often runs as high as 250 to 300 barrels per vessel, and averages approximately 100 barrels each trip for which payment is not made. The carrier is consequently penalized in the amount of cargo which is not removed, and in effect has carried such amount as additional dead weight, by which the effective capacity of the vessel is curtailed.

The principal object of this invention is to enable the effective use of substantially the entire cargo capacity of the vessel and to reduce to a minimum, residual cargo which would tend to curtail the effective capacity.

It vis customary in vessels of this character to segregate the hold or hull of the vessel into compartments or tanks by transverse tank Walls and one or more longitudinal tank walls, substantially the entire vessel being covered with a deck. Y Each tank is provided with a suction pipe, connected through a header to a suitable pump, which may be carried on the barge or be on the dock where the barge is unloaded, for accomplishing unloading or emptying of the tanks. As is well known in pumping practice, a serious problem is that of cavitation (Yor the tendency of the atmosphere tov break through the seal of the surrounding liquid and` destroy the pumping vacuum) which is dependent on the rate of pumping, the size of the suction pipe, and other factors. Since cavitation becomes effective before the level of the liquid reaches the bottom of lthe suction pipe, and removalof liquid Ibelow such point is almost4 impossible, aconsiderable quantity of liquid remains in thecompartment, asthe residual cargo. In addition whenever cavitation breaks through and destroys the vacuum, pumping not only stops, but it issubstantially impossible to reprime and start pumping again.

The evil of cavitation in emptying tankerbarges is one of the prime reasons for residual cargo. V present problem, largely through the general adoption of the unloading procedure, in which the It has .been lessened to the point of lthe' barge is partially emptied on a substantially even keel, and then is subsequently emptied progressively from end to end. In` this manner, as one end of the barge is emptied, it floats more buoyantly and the barge is longitudinally tilted. By positioning the suction pipes adjacent the tank Walls and so emptying the barge as to cause it to tilt toward the pipes and adjacent tank walls, the liquid in each compartment ovvs toward the tank wall, and removal is thereby assisted. `But even in the use of this unloading procedure the problem of residual cargo continues to exist, and this invention is directed to the solution of that problem, regardless of the procedure under which it arises.

The basic means by which this solution is accomplished is in the novel and useful sump keel which is provided for a vessel such as a tanker barge. If an attempt was made to provide an individual sump for each tank the result would be that a tremendous drag, seriously impeding the passage of the barge, would be created. In this invention all of the benets obtainable from individual sumps are achieved without increase of drag or sacrifice to the speed of the vessel, and at the same time acquiring other andfurther benets as will become apparent hereinafter.

The objects of this invention are:

To provide means facilitating the maximum effective use of cargo space in a tanker vessel;

To provide means for minimizing residual cargo, in vessel unloading;

To provide means concentrating the liquid adjacent the suction pipe, without substantially increasing the drag of the vessel;

To provide a tanker vessel having a sump keel extending longitudinally of the vessel, and adapted to receive and concentrate liquid adjacent the suction pipe;

To provide suction pipes, for use with tanker vessels adapted for longitudinal tilting during unloading, the pipes being beveled at their lower ends in substantial parallelism with liquid level at maximum tilt of the vessel;

To provide tanker vessels having sump keels and beveled suction pipes, cooperatively positioned to substantially prevent cavitation and to assure maximum effective use of tank space in such vessel; and

To provide a sump adapted tothe dual purpose of facilitating pumping and acting as a keel.

The means by which the foregoing and other vobjects of the invention are accomplished, and the manner of their accomplishment, will be readily understood on reference to the accompanying specication and to the drawings, in which a typical tanker barge, including the improvements of this invention, is illustrated.

In the drawings:

Fig. 1 is a plan view of the tanker barge, with the deck partially broken away to show the interior construction.

Fig. 2 is a sectional elevation, taken as along the line II-II of Fig. 1.

Fig. 3 is a sectional elevation, as along the line III-III of Fig. 2.

Fig. 4 is a fragmental sectional view on an enlarged scale, taken as on the line IV-IV of Fig. 3; and

Fig. 5 is a fragmental sectional View on a further enlarged scale, taken as on line-V-V of Fig. 4.

Referring now to the drawings in which the various parts are indicated by numerals:

The tanker barge comprises a hull II and a deck I2. Hull II includes side plates I3 and I4, and bottom plate I5, the bottom plate being curved upwardly at the front to join deck I2 and form the bow of the barge, and being similarly curved upwardly at the rear of the barge to meet the deck and form the stern. Deck I2 extends from bow to stern and is secured to bottom plate I5 along each junction and is also secured to side plates I3, I4, so as to cover the hull.

I-Iull II is subdivided into a plurality of compartmentsor tanks I1 by a longitudinal tankwall I9, and a plurality of transverse tank walls 2l. These tank walls extend vertically from bottom plate I5 to deck I2, and are secured thereto in usual manner, as by angle irons 23, 24, or in other desired manner. Tank wall I9 extends from bow to stern and is secured to each in desired manner, as by angle irons 25, and tank walls 2I extend from side plate to side plate and are similarly secured in position as by angle irons 26.

As shown'tank wall 2I divides the tanks I1 into parallel rows longitudinally, a port row and a starboard row. Each of the tanks I1 is preferably provided with a manhole 21, having a removable cover for use in iilling the tanks or for cleaning or for supervision of liquid withdrawal or other operations.

According to the present invention, underlying each row of tanks, there is a sump keel, the port keel being 29, and the starboard keel SI. Each of the sump keels comprises a substantially U- shaped channel section, exten-ding from end to end of the vessel, and curving symmetrically with bottom plate I5 at both stern and bow. Keels 29, 3I are throughout their length preferably secured to and depended from bottom plate I5, as at 33, 35. Bottom plate I5 is interrupted adjacent the points of connection 33, 55, so as to leave the channels 29, 3i open for the entry of the liquid of tanks I1. It will be noted that a portion of the channel keel 29 or 3i underlies each of tanks I1. The keels are interrupted at each of the transverse tank walls 2|, tank walls 2I having portions 31 extended into the channel keel, and blocking the channel keels to prevent flow of liquid past tank walls 2 I, or between tanks I1. In this manner there is no danger of intermingling of tank contents which would prove of particular importance in the event that liquids of varying characteristics were carried in the individual tanks.

Emptying of the vessel is accomplished through customary pumping, as by a pump 39, shown here mounted on the deck I2 of the barge, but which may and very often is mounted on the wharf (not shown) or other point of vantage on the shore. In the set-up illustrated, 4I, 43 are longitudinal headers communicated with pump 39 through T-pipe 45. It will be noted that T- pipe 45 is provided with capped extensions 41, 48, and that headers 4I, 43, terminate in T-pipe 49, which is provided with similar capped extensions These extensions are provided to accommodate a. pump installed on shore or wharf, in the most convenient position, any of the extensions being adapted if connected to a pump to permit withdrawal therethrough of the barge contents.

Connected to headers 4I, 43 are suction pipes 5I, each tank I1 having an individual pipe 5I inserted therein through a suitable opening in deck I2. Each pipe 5I is suitably valved as by valves 53, to permit individual cutoff as desired. It will be noted that while two headers 4I, 43 are shown, a single header might be satisfactorily employed.

A pipe 5I is positioned in each tank I1 adjacent a transverse tank wall 2|, all pipes 5I being similarly positioned in their respective tanks I1. The lower end 55, of each pipe 5I, is inserted in the portion of the Sump keel underlying the individual tank I1. Pipe end is also preferably beveled, as at 51, and the pipe so turned that the higher edge of the bevel is toward an adjacent tank wall 2|.

In general the construction of the barge is indicated of customary type, and is not fully discussed herein. The hull I I is assembled, and the channel keels 29, 3I are welded to bottom plate I5. Plate I5 may then be cut out inside to open the tops of the channels. It will be noted, however, that the bottom plate I5 may be cut before the channel keels 29, 3| are positioned, or as above stated, after keel positioning, or in new construction individual plates of width adapted to extend to the channel, may be used without departing from the scope hereof.

After the hull and keels are assembled and joined, suitable cross beams, as beams 59, may be placed, if desired, to laterally strengthen the barge, and suitable deck beams, as beams 6 I may be secured from side plate to side plate to provide suitable deck support at desired deck level. The longitudinal and transverse tank walls'I9, 2| are set up in usual manner, but have portions 31 extending into channel keels 29, 3I to block the channel keels as described. Deck I2, with manholes 21, may then be laid on beams 6I, and secured to beams 6I, to side plates I3, I4, and to the upwardly turned ends of bottom plate I5, fore and aft.

The pipe system may be set up, suction pipes 5I inserted through suitable openings in deck I2 into tanks I1, valves 53 attached, and headers 4I, 43 mounted and connected into T-pipes 45, 49, all in customary fashion. When pipes 5I are prepared for insertion into tanks I1, lower portions 55 are preferably beveled as at 51, to provide a bevel compensating for the tilt of the vessel during unloading, this bevel being such that the bottom end of the pipe is level, as the level of the last liquid in the tank approaches the end of the pipe. When pipes 5I are inserted they are positioned so that the higher edge of bevel 51 is toward an adjacent tank wall. Lower portion 55 is introduced into channel keel 29, in each of the port tanks and into channel keel 3| in each of the starboard tanks and is extended downwardly near the bottom of the channel.

In operation, during unloading of the tanker barge, all valves 53 are usually opened at the beginning of pumping and all tanks l1 partially emptied, usually about half way. When the desired point has been reached, the emptying is completed in a progression from end to end of the barge. Thus all valves 53, except those for the suction pipes of the tanks nearest the end chosen for beginning of the progression, are closed, and pumping withdrawal is had from those tanks until their contents are exhausted. In each instance it is desired to begin the progression at-the end desired to be first lightened to cause the barge to tilt toward the suction pipes. In the instance illustrated, the progressive withdrawal would be begun with tanks l'l-A (Figs. 1 and 2), the Valves 53-A for suction pipes I-A, remaining open until the contents of tanks I'i-A is exhausted. As the tanks l'I-A are emptied they become more buoyant and float higher, tending to tilt the barge, so that liquid in tanks II-A tend to flow toward tank wall 2 I A, to maintain pumping depth as far as possible. The 1iquid is drawn by pipe 5l-A and tends to collect in channels 29, 3| adjacent Walls ZI-A. Thus the liquid will flow into the channel which acts as a sump and the bottom of the tanks II-A will be cleared. As the channels have substantial depth, cavitation is substantially prevented through the maintenance of a pumping level in the channel after the remainder of the tank has been emptied, and the residual liquid is reduced to a minimum.

As emptying of tanks I'l-A is completed valves 53--B, for suction pipes 5|-B, are opened and tanks Il--B are emptied in manner similar to that just described. This procedure is repeated progressively through the length of the barge, until all the tanks are emptied.

The tilt of the vessel during cargo discharge is illustrated in Fig. 4, and the manner in which the liquid flows into the channel and toward tank wall 2l is shown. The bevel 51 of the pipe 5l is formed along a line substantially parallel with the liquid surface at maximum tilt in the tank I'I in which the pipe is inserted. The angle of bevel 51 will preferably vary, depending on the position of the tank in the barge. 'Ihat is the angle of the bevel of pipe 5I--A, being in tank ll-A where the least tilt would occur, Would be less than the angle of the bevel of pipe 5|-X in tank l'l-X where the tilt would be greater. The bevels 51 are of importance in assisting materially in preventing cavitation, by permitting the level of liquid to be lowered further down pipes 5l, before the seal is broken. The provision of parallelism of the line of bevel with the liquid level provides an even withdrawal of the maximum amount of liquid from each tank.

It will be noted that as channel keels 29, 3l underlie cross beams 59, the beams do not interfere with the ow of liquid toward the tank walls in the channels, while in the absence of the channel keels the beams would have to have openings for liquid passage, if serious interference was to be avoided.

It will also be noted that existing barges may readily be changed to include this invention by securing channel keels of the type described to the bottom of such barges, and cutting the bottom plates to provide a ready entrance opening for liquid, into which a suction pipe might be inserted.

It will also be noted that the continuous keel will not impede the longitudinal motion of the barge as would a series of sumps, but that the sump keel acts as a true keel, and by its depth beneficiary limits lateral movement of the barge.

It will be understood that the embodiment of the invention shown and described is intended as typical, and that the sump keel inay be used with other type vessels without departing from thescope of this invention, and that the shape of the sump keel may be varied without departing from the scope of this invention.

I claim:

l. In a vessel, which includes a plurality of tanks having substantially nat bottoms and adapted to carry liquid, a keel comprising a substantially channel-shaped member depended below and extending along said tank bottoms, said keel being divided into a plurality of sections, each corresponding to a said tank and being communicated with the interior of said tank to serve as a sump for the liquid carried thereby.

2. In a vessel, which includes a plurality of tanks having substantially flat bottoms and adapted to carry liquids, and means for emptying said tanks, including suction pipes, each said tank having one of said pipes inserted therein, a keel, comprising a substantially channelshaped member depended below and extending along said tank bottoms, said keel being divided into a plurality of sections, each said section corresponding to a said tank and being communicated with the interior of said tank, to serve as a sump for liquid therein, each said pipe being extended into the sump section related to the tank in which said pipe is inserted.

3. A substantially flat bottomed barge, having its interior segregated into a plurality of tanks adapted for liquid transportation, said barge having a member of substantially U-shaped cross section depended from its bottom and longitudinally extending from end to end thereof, the interior of said member being segregated into sections corresponding with said tanks, each said tank being communicated with a said section, whereby said sections serve as sumps for theirrelated said tanks, the exterior of said member being continuous to minimize lateral movement of said barge.

4. A vessel, which includes a plurality of tanks, adapted to carry liquid, arranged in longitudinal parallel rows, each said tank row having, depended therebelow and extending along the bottom thereof, a keel, comprising a substantially channel-shaped member, each said keel being segregated into sections, each corresponding with a said tank of its related said row and being communicated with the interior of its related said tank to serve as a sump for the liquid therein.

5. A vessel, which includes a plurality of tanks adapted to carry liquid, arranged in longitudinal parallel rows, and means for emptying said tanks, including suction pipes, each said tank having one of said pipes inserted therein, each said vtank row having, depended therebelow and extending along the bottom thereof, a keel, comprising a substantially channel-shaped member, each said keel being segregated into sections each corresponding with a said tank of its related said row and being communicated with the interior of its related said tank to serve as a sump for the liquid therein, the pipe inserted in each said tank being extended into its related said keel section.

6. In combination with a vessel having a plurality of tanks for carrying liquid, said vessel being adapted to be emptied progressively from end to end and to longitudinally tilt as said emptying progresses, means for accomplishing said emptying which includes a plurality of suction pipes, each said tank having one of said pipes inserted therein, each said pipe having its lower end beveled along a line substantially parallel with the liquid level in said vessel upon tilting.

7. In combination with a vessel having a plurality of tanks for carrying liquid, said vessel being adapted to be emptied progressively from end to end and to longitudinally tilt as said emptying progresses, sump sections, each said tank having a said section related thereto, and means for emptying said tanks which includes a plurality of suction pipes, having their respective lower ends beveled along a line substantially parallel With the liquid level in said vessel upon tilting, each said tank having one of said pipes inserted therein with the bevel of said pipe extended into the said sump section related to the tank.

8. In combination with a vessel, having a plurality of tanks for carrying liquid, said vessel being adapted to be emptied progressively from end to end, and longitudinally tilt as said emptying progresses, means for accomplishing said emptying which includes a plurality of suction pipes, each said tank having one of said pipes inserted therein, each said pipe having its lower end beveled, the respective said pipe bevels varying from tank to tank, whereby the line of bevel of each said pipe is substantially parallel with the liquid level of its related said tank at maximum tilt thereof.

JOHN PREUSS.

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