United States Patent 3791393

Device for cleaning the interior of elongated tanks or tanks where access to the interior is limited consisting of a tank cleaning machine attached to a source of cleaning liquid. The tank cleaning machine is movably affixed to a track and drives along the track during the cleaning operation, the track extending through the area of the tank to be cleaned so that the cleaning operation extends to portions of tank interior where access from the outside is limited. An externally mounted gas tight winch is preferred as the drive means. A flexible hose provides connection between the tank cleaning machine and the source of cleaning liquid and the hose may be calibrated so that the position of the tank cleaning machine within the tank can be determined. Entry to the tank interior for mounting and dismounting the tank cleaning machine on the track is through an entry port located adjacent one end of the track.

Application Number:
Publication Date:
Filing Date:
Primary Class:
Other Classes:
134/172, 239/751, 239/752
International Classes:
B63B57/02; (IPC1-7): B08B3/02; B08B9/08
Field of Search:
134/167R,167C,168R,172,179 239
View Patent Images:
US Patent References:
3065760Stabilizing attachment for tank washing machines1962-11-27Cailas
2024374Overhead irrigation system1935-12-17Langebrake
2006709Fire fighting system1935-07-02Conran
1628141Cleaning device1927-05-10Gray

Primary Examiner:
Bleutge, Robert L.
Attorney, Agent or Firm:
Roessel, Theodore B.
I claim

1. Apparatus for the cleaning of the interior of a tank having an entry port comprising:

2. Apparatus of claim 1, wherein at least one end of said elongate support means terminates adjacent said entry port in said tank for introducing and mounting thereon said carriage means and said tank cleaning machine.

3. Apparatus according to claim 1 in which said elongate support means comprises a flange and a central web extending upwardly therefrom and running along the length of said support means, and said carriage means includes at least one rotatably mounted roller carried by said flange on each side of said central web for movably supporting said carriage means and said tank cleaning means on said support means.

4. Apparatus according to claim 1 in which said elongate support means is an I-section rail, the upper and lower flange and central webb thereof defining a pair of channels running along the length of said rail and adapted to receive rollers of said carriage means.

5. The apparatus of claim 1 wherein means for supplying cleaning liquid to said tank cleaning machine comprises a flexible hose connected at one end to an external source of cleaning liquid and passing through said entry port and connected at its other end to said tank cleaning machine, said flexible hose having hose support means affixed thereto at spaced apart intervals along said hose length, said hose support means being adapted to be received by said elongate support means as said hose is extended into said tank.

6. The apparatus of claim 5, wherein said hose is calibrated for determination of the position of said tank cleaning machine within said tank.

7. The apparatus of claim 1, wherein said means for inducing movement of said carriage means and said tank cleaning machine comprises an externally mounted winch and cable, said cable communicating with the interior of said tank and being attached to said carriage means for effecting movement thereof along said support means responsive to the operation of said winch.

8. The apparatus of claim 1, wherein said means for inducing movement of said carriage means and said tank cleaning machine comprises a gas tight winch externally mounted in a gas tight manner on said tank over an aperture communicating with the interior of said tank, said winch and aperture positioned on said tank above the end of said elongate support means remote from said tank entry port, a winch cable leading from said winch and through said aperture being connected to said carriage means for moving said carriage means and said tank cleaning machine along said support means responsive to the operation of said winch.


This invention concerns the cleaning of the interior of tanks and finds particular although not exclusive application in the cleaning of certain types of ships tanks.


Tank cleaning machines are already known in which a rotating jet of water is used to clean the interior of the tank. Tank cleaning machines of this type are described for example in U.S. Pat. Nos. 3,326,468 and 3,637,138. These machines are usually lowered into position through entry ports and hang down into the tank for cleaning. It is also known, to provide tank cleaning machines as fixtures inside the tank, the machines being so disposed that the whole interior of the tank can be cleaned with an appropriate number of suitably located machines. Such a device is described in U. S. Pat. No. 3,625,234.

There occur particular problems in cleaning certain types of tanks, particularly, those of long narrow shape. This type of tank can occur in practice, for example as the wing and/or deep tanks of Oil and Bulk Ore vessels (OBO vessels). These tanks often extend the full length of the ship and normally carry ballast, the deep tanks extending along the bottom of the vessel and the wing or top hopper tanks extending along each side of the ship on either side of the main centre tanks.

These tanks are usually divided lengthwise into a number of bays, the partitions between each bay having an aperture therein for communication between the bays. The purpose of the partitions is to reduce the movement of liquid ballast within the tanks while the ship is under way.

It has been proposed that these tanks, normally used for ballast, be employed as useful cargo-carrying space, provided that the cargo used is compatible with the ballast i.e. it should be liquid, for example oil.

One drawback of these proposals is that it is very difficult to clean this type of tank due to its shape. With the type of tank cleaning machines mentioned above each bay of the tank would have to be considered as a separate tank, thereby necessitating either one entry port for each bay, the machine being transferred from one to another of these ports, or a separate machine for each bay. Thus the cost of cleaning such tanks can be high and may require a number of separate operations thereby increasing the time spent in cleaning. Further, a large number of entry ports in the tank can cause weakness in the structure.

One object of the present invention is to provide apparatus which is capable of cleaning the above mentioned special tanks without these disadvantages. While the invention finds particular application in cleaning ships holds, the apparatus also has several non-marine uses, for example in the cleaning of the interior of road tankers or underground tanks where access is difficult.


Thus in accordance with the present invention there is provided apparatus for cleaning the interior of tanks said apparatus comprising an elongate support for attachment within said tank and over the length thereof to be cleaned, a tank cleaning machine having means for mounting it so as to be movable along said support and means for moving said cleaning machine along said support.

Thus the support which may for example be a rail, which will normally be a permanent fixture within the tank, may extend the full length of a tank or if preferred may extend around the periphery of such tanks for better cleaning coverage. In use the tank cleaning machine will be moved from place to place along this rail so as to clean the whole of the tank. Several methods may be employed to move the cleaning machine. Thus, for example a continuous cable may be attached by its ends to opposite side of the cleaning machine and may be guided along the rail by means of guide rollers to a drive means outside the tank. The cable being so arranged that the cleaning machine may be moved in either direction depending upon the direction of operation of the drive means.

However, especially where an elongate tank is to be cleaned it is preferred to provide an entry to the tank adjacent one end of the elongate support for a cleaning machine which can be drawn along the support or rail, by a cable or the like controlled by a winch located adjacent the other end of the tank. As the machine moves along the tank the hose by which a cleaning liquid, generally water, is supplied to the machine is paid off a reel and this hose can be reeled up to draw the machine back again.

If desired the entry could be for instance centrally disposed and two supports or rails extending towards opposite ends of the tank could be provided. Two winches could then be used or a simple winch having cables arranged so that one winds on while the other winds off depending on the direction in which the machine is to move.

The hose supplying liquid to the cleaning machine may also enter the tank by means of said entry port. In order to guide the hose along the rail and also to reduce sagging of the same hose rollers may be provided. These are affixed to the hose at intervals therealong as the hose is fed into the tank during operation of the machine. Each hose roller is attached to the rail for movement therealong. The winch cable may also be provided with similar guide means.

It is also useful to calibrate the hose in some way so that the approximate position of the cleaning machine on the rail can be determined.


FIG. 1 is a perspective view broken away to show the apparatus of the invention mounted in a wing tank of an oil and bulk ore vessel

FIG. 2 is an enlarged, partially exploded, perspective view of the apparatus of the invention.


In order that the invention may be better understood one embodiment thereof will now be described with reference to the accompanying drawing which shows in the upper part thereof a part cross-sectional perspective view of a tank cleaning apparatus according to the invention fitted into one wing tank of an OBO vessel, and in the lower part thereof an enlarge part exploded perspective view of the tank cleaning apparatus.

The tank cleaning apparatus comprises an elongate support in the form of an I-section rail 1 which is attached, for example, to the inside of the roof of a tank to be cleaned by suitable hangers (not shown). In the drawing the rail 1 is shown mounted within a wing tank 2 with its characteristically triangular cross-section. As mentioned previously the wing tanks are equipped with a number of laterally extending partitions having an aperture centrally disposed therein. For the sake of clarity in the drawing the position of the partitions is shown by solid lines such as 3, the apertures in the partitions being represented by broken lines such as 4.

Rail 1 is spaced apart from the tank roof a sufficient distance so as to be clear the upper portion of partition 3 and communicates with all tank sections through the apertures defined by broken lines 4.

One end of rail 1 is curved upwardly and terminates just short of an entry port in the form of a hatch opening 6 in the top of the tank. During use of the tank for carrying cargo or ballast opening 6 is closed, for example by means of a hatch cover (not shown) which is tightened onto the hatch opening in a conventional manner using studs 7.

The rail 1 extends along the length of tank 2, passing from bay to bay of the tank through apertures 4. As shown the rail extends in a straight line over the area to be cleaned. However depending upon the shape of the tank and the area to be cleaned the rail may follow whatever path is found to most efficiently clean the required area.

Near the end of the rail 1, remote from opening 6, a gas tight winch 8 is externally mounted on the roof of the tank. The winch is attached in a gas tight manner to the roof of the tank by means of bolts 9 and may be either hand driven, as by handle 10, or driven by compressed air.

Extending downwardly from the winch into the tank is a winch cable 11, for example of stainless steel, which passes first over a winch roller 12 and thence to a first winch cable guide roller 13 affixed to that end of rail 1 nearest the winch. At the other end of the winch cable a shackle 14 is provided, which shackle is adapted to be secured to a securing lug 15 on opening 6 when the apparatus is not in use and/or whilst the ship is under way.

If desired further winch cable guide rollers may be employed along the length of the rail in order to prevent sagging of the cable. Unlike guide roller 13 these further rollers are free to move on rail 1.

When the apparatus is required for use the hatch cover is removed from opening 6 to reveal the upwardly facing end of rail 1 and one end of winch cable 11. A tank cleaning machine 16 is then fitted onto rail 1 for movement therealong. Thus in this example the tank cleaning machine 16 is provided with a carriage consisting of pair of rollers 17 rotatably attached on the inner facing surfaces of a U-bracket 18 attached to cleaning machine 16. In use rollers 17 rest on either side of the lower flange of rail 1 whilst the web of the rail passes between the rollers.

The supply of cleaning fluid, usually water, to the tank cleaning machine is by way of a flexible hose 19. The fluid is supplied to the upper part of a swivel joint 20 which is included in order to allow free swinging movement of the machine 16. A swivel joint preferred for this application is described in U. S. Pat. No. 3,625,234.

In order to effect movement of the machine 16 along rail 1 the winch cable 11 is attached by means of shackle 14 to the machine. Operation of the winch then draws the machine 16 along the rail 1 towards the winch to clean the required area. If desired the machine 16 may be operated simultaneously with movement thereof along rail 1. Alternatively, the cleaning operation can be carried out in a number of discrete steps, moving machine 16 along a predetermined distance between each step.

Supply hose 19 passes out of tank 2 through opening 6 and is thereafter connected to a suitable supply. As the tank cleaning machine moves towards winch 8 the hose 19 passes into the tank via opening 7. In order to aid this operation a hose reel 21 may be used to pay out the hose. Suitable hose reels for this purpose are known.

Due to the large weight of the hose when filled with cleaning fluid it is preferred to provide means for supporting the hose onto the rail 1 as the tank cleaning machine moves towards the winch. Thus, a number of hose rolles 22 may be employed which have wheels 23 for movably supporting the rollers 22 on the rail. Rollers 22 are attached to the hose at intervals therealong as the hose passes into opening 6. In order to affix rollers 22 to the hose, a pair of semi-circular jaws 24, hinged at 25, are provided. The jaws 24 are clipped around the hose and fixed in the closed position gripping the hose. The distance between each roller 22 may be varied in dependence on the linearity or otherwise of rail 1. for example the greater the curvature of the rail the smaller the distance between each roller 22. A typical distance between hose rollers 22 on a straight run is 6 feet.

In order to ascertain the position of the machine 16 during operation the hose 19 may be calibrated, such as by graduations on the hose, to show the length paid out. This feature enables correct positioning of the machine in each bay of a long tank.

To use the apparatus the tank cleaning machine 16 is fitted by hand onto the upwardly facing end of rail 1. Shackle 14 at the end of winch cable 11 is then detached from lug 15 and attached to suitable mounting means on the machine 16.

The winch is then operated to draw the machine 16 along the rail 1, cleaning being undertaken either continuously or at discrete intervals along rail 1 as aforesaid. When machine 16 has reached the limit of its travel, or the required amount of cleaning has been completed the machine 16 is returned along the rail towards opening 6 by pulling hose 19 out of opening 6. The machine may then be removed by hand from opening 6.

Thus it will be seen that the complete cleaning operation may be undertaken without any more access to the tank being necessary than that provided by the single hatch. This feature enables normally inaccessible tanks to be cleaned with ease.