Unloading facility for flexible water transporting barges

A flexible barge containing fresh water is unloaded on a dry dock which is gradually raised from a submerged condition as the fresh water is pumped out of the barge. The deck of the dry dock is formed with a basin adjacent one end thereof and the dry dock is tilted near the end of the unloading operation so that water will drain in the barge toward the basin and collect in the barge in the basin to be pumped out.

TECHNICAL FIELD 
The present invention relates to flexible barges for transporting fresh 
water, and more particularly to a facility for unloading the fresh water 
from such a barge. 
BACKGROUND OF THE INVENTION 
Transporting of fresh water in a floating flexible barge (hereinafter "FB") 
towed on salt water seas from a region with excess fresh water to a region 
having shortages has been proposed. This requires the use of special 
handling facilities for emptying the FBs and delivering the fresh water 
into a municipal pipeline or other water transport or storage facility. A 
typical FB would be formed from a suitable fabric material such as vinyl 
and could be 500 feet long and about 50 feet in diameter, with a draft of 
about 30 feet. Such an FB would hold more than 6,000,000 gallons of fresh 
water and displace nearly 24,000 long tons. The FB would have a front 
towing bridle for connection to a towing line from a tug and for receiving 
mooring lines, and preferably would have aft fittings for mooring lines. 
The present invention is directed at providing an FB handling facility and 
unloading procedure which makes speedy handling and unloading of an FB 
possible, and does so in a practical and economically feasible manner. 
SUMMARY OF THE INVENTION 
In accordance with the invention a concrete float is provided as a working 
platform which is used in conjunction with one or more elongated 
submersible floats, hereinafter called dry docks, for gradually raising 
FBs docked adjacent the working platform as they are being emptied. Each 
dry dock is capable of handling an FB, and has divided ballast tanks 
adjacent the ends of its hull to adjust the trim and pitch of the dry dock 
as well as its draft. A basin is preferably provided at the working 
platform end of the dry dock beneath an adjustable discharge pipe which is 
connected to the suction side of a suitable pump on the working platform, 
and depends, from a crane on the working platform into a discharge port in 
the FB. The portion of the FB seated in this basin is kept filled with 
fresh water near the end of the unloading procedure by longitudinally 
tilting the dry dock by approximate manipulation of the amount of ballast 
in the ballast tanks. In this manner the FB can be substantially 
completely emptied.

DETAILED DESCRIPTION OF THE DRAWINGS 
Referring to the drawings, for purposes of example an FB unloading facility 
is illustrated for handling a single FB at a time. The facility comprises 
a working platform 10 and a submersible elongated float 12 (dry dock). 
Preferably the platform 10 is a concrete float to compensate for tide 
changes. Typically the floating platform 10 is moored by a pair of slides 
acting on a pair of positioning piles 14-15 at one end of the float and 
positioning is assisted by additional pairs of front and back guide piles 
16-17. The platform 10 carries a pump 29, a mooring winch 21, a shed 22 
with air compressors, and a bank of compressed air receivers 23 charged by 
the air compressors. The suction side of the pump 20 is connected to a 
suction hose 24 and the discharge side of the pump is connected to a pipe 
25 leading to a main. The suction hose 24 is adjustably suspended over the 
dry dock 12 by the reach boom of a crane 26. Preferably the crane mast is 
telescopic and/or the boom is swing-mounted on the mast so that the 
discharge hose can be easily manipulated vertically and horizontally. A 
ramp 27 gives access to the platform 10 from an adjacent stationary dock 
or other shoreside facility. 
The dry dock 12 comprises an elongated hull 30 having a deck 31 and fore 
and aft ballast tanks 32, 33. Forwardly of the front ballast tank 32 the 
deck 31 has a bowl-shaped basin 34. Preferably the ballast tanks 32, 33 
are each divided into port and starboard compartments which are connected 
by suitable pipes and flexible hoses to the bank 23 of compressed air 
storage receivers for selectively supplying compressed air to the 
compartments in the ballast tanks 32, 33. These compartments also have 
discharge lines extending from their lower ends to valves on the platform 
10 for discharging ballast water responsive to introduction of compressed 
air to the ballast tank compartments from the compressed air receivers 23. 
The dry dock hull 30 extends rearwardly of the aft ballast tank 33 by a 
stern section 30a which extends between a pair of suitable vertical guide 
structures 48 supported by pilings 49. Preferably the deck 31 of the dry 
dock is made slightly concave across most of its width. 
To empty a flexible barge 40 after it is moored over the dry dock 12 when 
the latter is submerged with the ballast tanks 32-33 filled with sea 
water. The suction hose 24 is then inserted into the barge through a port 
adjacent the forward end thereof. As the fresh water in the barge is 
pumped out the dry dock is gradually raised by introducing compressed air 
into the ballast tanks. FIG. 3 shows the final steps to empty the barge. 
In frame 3-A the dry dock is still submerged and the barge still contains 
water for substantially its full length. In frame 3-B the barge emptying 
operation has progressed to the point that the barge is nearly empty and 
the dry dock level is above the sea surface. Then the amount of sea water 
in the ballast tanks is adjusted so that the deck of the dry dock is 
pitched downwardly in the forward direction toward the float approximately 
6 degrees. This causes the water remaining in the barge to drain 
forwardly. The portion of the flexible barge above the basin 34 will 
responsively depress into the basin to contain the remaining water. The 
portion of the barge occupying the basin is then pumped out as the dry 
dock is returned to a level condition (frame 3-C). 
Although only one unloading berth has been shown and described, it will be 
appreciated that multi-berths can be provided at an unloading facility. 
From the foregoing it will be appreciated that, although specific 
embodiments of the invention have been described herein for purposes of 
illustration, various modifications may be made without deviating from the 
spirit and scope of the invention. Accordingly, the invention is not 
limited except as by the appended claims.