Oil tanker and method for recovering oil from submerged oil tanker

A system for recovering petroleum products such as oil from a sunken oil transportation vessel. The system includes first and second flexible conduits communicating with the oil-containing compartments. The conduits are released upon the vessel becoming submerged. The free ends of the conduits are connected respectively to a pump for pumping sea water into the compartment to displace the oil. The second conduit is connected to a recovery container on the surface. The displaced oil is forced through the second conduit to the recovery container. The recovery container is, in the preferred embodiment, provided on a fleet or network of recovery vessels which then transport the recovered oil to port for off-loading. In the preferred embodiment, the flexible conduits are associated with a float which releases or carries the conduits to the surface so that underwater recovery operations are minimized.

FIELD OF THE INVENTION 
The present invention relates to a system for recovering oil from a marine 
vessel and more particularly relates to a system which facilitates 
immediate recovery of oil from a sunken or submerged vessel such as an oil 
tanker or barge. The present invention is particularly applicable to 
situations in which the oil is contained in a sunken vessel, such as a 
tanker or barge which is at a depth which makes pumping of the oil from 
the vessel difficult or impossible thereby impeding immediate retrieval of 
the oil before spillage or leakage occurs which will result in severe, 
detrimental environmental effects. 
BACKGROUND OF THE INVENTION 
Petroleum products such as crude oil, bunker oil, diesel oil, and gasoline 
are conventionally transported in bulk quantities in ocean-going vessels 
such as selfpropelled barges, tankers or super tankers. Tankers often have 
a number of compartments which may contain from 1,000 to as many as 24,000 
barrels of oil. The large super tankers may have a capacity of one to two 
million barrels of oil. 
Tankers and barges, when in transit on the ocean, are exposed to various 
maritime perils which may cause the vessel to sink, necessitating 
immediate salvage of the oil cargo both for economic and environmental 
reasons. The environmental effects of spills or leakage from sunken 
vessels or vessels run aground are well known and result in harm to both 
the ecology and the environment In addition, the loss of the oil due to 
spillage or leakage represents a substantial economic loss to the owners. 
Thus, there exists a need for a simple, effective and expedient system of 
removing and recovering oil from sunken vessels, particularly those which 
rest in depths of greater than 10 or so meters. A vessel sunk below this 
depth presents particular problems. Conventional recovery methods 
generally require that pipes or conduits be connected to the various 
compartments so that the oil may be pumped from the compartments to a 
surface recovery. However, if the vessel is below 10 meters or so, pumping 
is difficult because of the substantial suction required which often will 
exceed the capacity of pumping equipment. Further, making connections to a 
sunken vessel requires the use of divers working at excessive depths which 
can be hazardous. 
In addition, rough seas or weather can substantially complicate recovery 
attempts, increasing the hazards to divers and other recovery personnel. 
Accordingly, there exists a need for a simple, expedient and effective 
system for recovering oil from sunken oil vessels such as tankers and 
super tankers. 
Accordingly, it is a primary object of the present invention to provide a 
system which allows the immediate and expedient recovery of oil from 
vessels which are sunk and which accommodates the transfer of the oil to a 
surface vessel from the sunken vessel, minimizing the environmental 
exposure. 
The present system can be easily applied as original equipment on new 
vessels or can be easily retrofit to existing vessels. 
The system is complimentary to double hull construction and is inexpensive 
to install. 
The present system also overcomes or eliminates spillage problems attendant 
to conventional recovery systems. In many situations, sunken vessels 
represent a substantial environmental problem if recovery attempts fail. 
The failed oil recovery attempts often result in release of the oil. For 
this reason, many owners and insurance companies will not risk recovery 
attempts and therefore the sunken vessel is left to allow nature to take 
its course which ultimately may result in release of the oil due to 
movement of the submerged vessel which would occur over a period of time. 
The present invention relies in a system in which water such as sea water 
is pumped into the oil-containing compartments of the vessel in distress. 
There are several prior art patents which disclose methods and apparatus 
for displacing oil and sea water in tanks of an oil tanker. However, these 
patents do not disclose displacement systems for recovering oil from a 
tanker in distress. 
The early patent to Zolling, U.S. Pat. No. 1,103,239, relates to an 
improved tanker which has means for rapidly discharging the fluid through 
a series of suction pipes which project within the compartments. Inlet 
pipes are connected at suitable locations to sea cocks in the hold of the 
vessel below the water line and will admit water into the hold of the 
vessel to float the oil which has a lighter specific gravity than water. 
The suction pipes are provided with float valves so that as the level of 
the oil recedes to a point adjacent the lower end of the suction pipes, 
sea cocks are open to permit seawater to flow into the compartments. The 
floats are weighted so as not to be floated by the water until the water 
has reached a point where substantially all of the oil has been displaced. 
After the oil has been withdrawn from the compartment, the sea cocks are 
closed and the water is pumped or discharged from the compartments. 
Another patent which shows use of seawater for displacing oil is U.S. Pat. 
No. 4,178,868. This patent relates to a ballasting method for an oil 
tanker. The patent points out that oil tankers in transit are often empty 
or near empty. To reduce the possibility of capsizing and to stabilize the 
ship, it is common to ballast the ship by filling the tanks with seawater. 
The '868 patent suggests employment of a resilient membrane within the 
compartments to reduce contamination of the seawater used for ballast. 
As pointed out above, while both of the above patents suggest pumping of 
seawater into oil tanker compartments, neither suggest such an operation 
in connection with recovery of oil from a sunken vessel. 
SUMMARY OF THE INVENTION 
Accordingly, the present invention provides a system for recovery of oil 
cargo from a sunken vessel. The system includes a recovery vessel as 
pumping means capable of pumping, forcing sea water into the 
oil-containing compartments of the sunken vessel. Water has a greater 
specific gravity than petroleum products and will displace the petroleum 
products in the vessel. A container connected to a discharge of the 
compartment of the sunken vessel receives the displaced oil. The container 
may be on the same vessel as the pump or may be associated with a separate 
vessel so that when the recovery vessels are filled to capacity they may 
be returned to port and replaced with another recovery vessel. The 
operation continues until all of the oil in the various compartments in 
the sunken vessel is transferred to a recovery vessel on the surface. 
Alternatively, water may be introduced into the compartments of the sunken 
vessel by divers opening the sea cocks, although it is preferred that 
connections for pumping water into the compartments of the vessel in 
distress and for recovering the displaced oil be on the surface. 
To accomplish this, the various compartments of the oil-containing vessel 
are provided with inlet and discharge conduits which are flexible and 
normally stored in a collapsed, compact condition. The conduits have float 
means associated therewith so that upon submersion of the sinking vessel, 
the floats will be released to the surface carrying the water intake and 
oil discharge hoses to the surface for retrieval and connection by the 
recovery crew.

Referring to FIG. 1, a recovery situation is shown in which the system of 
the present invention is employed. Vessel 10 is shown submerged having 
sunk. Vessel 10 is an oil tanker or barge having one or a plurality of 
oil-containing compartments. As shown in FIGS. 2 and 3, the vessel 10 is 
shown having a hull 12 and which is of the double hull construction for 
further protection of the contents where upon puncture damage to the outer 
hull section only will not result in release of the contents of the 
various compartments 14, 14A, 14B, etc., as the inner hull protects 
against damage. The various compartments, 14, 14A, etc. are adapted to 
receive petroleum products and are covered by an upper deck 16. Each 
compartment has conventional connections 18 and 24 filling and withdrawing 
oil from the compartments. 
In addition to the conventional filling and discharge connections, the 
various compartments 14, 14A, etc. of the present invention are provided 
with components of the recovery system of the present invention as shown 
in FIG. 5. These components include an inlet pipe 22 depending within the 
compartment 14 a suitable distance such as to a location above the floor 
of the compartment. The inlet pipe 22 is connected to a flexible conduit 
24 which may be flexible rubberized fabric. The flexible conduit 24 is 
normally stored in a folded condition as shown in FIG. 5 within a housing 
or compartment 26. The conduit 24 is connected to the upper end of the 
pipe 22. The conduit may be of any suitable length as for example 100 
meters in length having at its opposite end a suitable coupling 28 to 
facilitate attachment to the discharge side of a pump. In addition, a 
float 30 is attached at or adjacent the coupling 28. 
Also, communicating with the compartment 14 is a discharge which includes a 
discharge pipe 32 which communicates with the interior of oil-containing 
compartment 14. The discharge pipe is similarly connected to a flexible 
conduit 34 which is of a suitable material such as a rubberized fabric and 
may be of a length comparable to conduit 24. The opposite end of conduit 
34 is provided with a fitting 38 which is adapted to be easily coupled to 
the inlet of an oil-receiving compartment of a recovery vessel. A float 40 
is positioned near the fitting 38. The 5 oil discharge conduit 34 is 
normally stored in a folded, collapsed position as shown in FIG. 5 within 
a suitable housing 46 on the deck of the vessel. 
A vent 50, as is conventional, communicates with the normal free-board area 
above the oil level in the compartment 14 and is provided with a float 
valve 52 in a suitable cage 54. The float being selected so that it will 
close off vent pipe 50 as the fluid level within the chamber 14 rises to 
the level of the float 52. Referring again to FIG. 1, the vessel 10 is 
shown in a sunken position a substantial distance above the ocean level 
60. The recovery system includes a vessel 70 which is provided with a pump 
75 for pumping sea water in volumes and at sufficient pressure to fill the 
compartments 14 of the sunken vessel 10. In addition, the recovery system 
includes one or more recovery tankers 80 and 90 which are positioned to 
receive the oil recovered from the sunken vessel 10. The vessels 70 and 90 
may be a single vessel but it is preferred that the recovery vessels 80 
and 90 be separate vessels so that when they are filled they may be sailed 
to port and unloaded. Additional recovery vessels 90 are ready for 
attachment to the sunken vessel when the initial recovery vessel 80 is 
filled to capacity. 
As seen in FIG. 1, conduits 24 and 34 of the second vessel have deployed to 
the surface which occurs automatically as a result of each of the conduits 
being attached to a float. Float 40 is shown on the surface of the ocean 
60 ready to be retrieved and attached to oil recovery vessel 80. Conduit 
24 is shown in the position of having been retrieved and attached to 
pumping unit 85 at 75 at coupling 28. Once conduit 34 is retrieved and 
properly connected to recovery vessel 80, pumping of water such as sea 
water is initiated. As the sea water enters compartment 14, oil is 
displaced and will be forced through conduit 34 to the recovery vessel. 
The check float valve 52 will close off vent 50 so oil is not discharged 
through the vent 50. The operation proceeds until compartment 14 is 
evacuated of oil. Conduits associated with the additional compartments, 
14A and 14B, are sequentially attached to the pump 28 and to the recovery 
vessel and the operation proceeds until all oil is recovered. 
In FIG. 1, only conduits associated with compartment 14 have been shown for 
clarity. It will be apparent that there will be a number of conduits 
released to the surface as oil tankers conventionally have multiple 
compartments. For clarity of illustration, only conduits 24 and 34 are 
shown. 
The floats which release the conduits communicating with the oil 
compartments, provide significant advantages. The floats carry the 
conduits to the surface so that connection to the pressure source, that is 
pump 75, and the recovery vessels can all be accomplished on the surface. 
It is, of course, possible that instead of connecting pump 75 to conduit 
24 to provide a source of pressurized sea water, that sea cocks associated 
with each of the compartments could be opened. However, this operation 
would necessitate the use of divers. 
Another advantage of the present system is that the floats, since they will 
assume a position on the surface of the water, will provide a marker for 
clearly indicating the location of the sunken vessel. The present system 
does not disturb the ship so that the possibility of inadvertent release 
of oil from the sunken vessel is substantially reduced. 
As indicated above, the recovery system of the present invention which 
incorporates conduits which release in the event of the sinking of a 
vessel may easily be incorporated into new ship construction or may be 
easily retrofit at minimum of cost. The system also has the advantage in 
that recovery can be accomplished even in heavy weather conditions as 
divers are normally not required in the recovery operation. The system 
also has the advantage in that recovery can be accomplished with vessels 
sunk at depths below ten or so meters which normally poses substantial 
recovery problems. 
While the principles of the invention have been made clear in the 
illustrative embodiments set forth above, it will be obvious to those 
skilled in the art to make various modifications to the structure, 
arrangement, proportion, elements, materials and components used in the 
practice of the invention. To the extent that these various modifications 
do not depart from the spirit and scope of the appended claims, they are 
intended to be encompassed therein.