US102554A - Improvement in dry-docks - Google Patents

Description

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Letters Patent No. 102,554, (lated May 3, 18.70.

.IMPROVEMENT IN DRY-Docks.

The Schedule referred to in these Letters Patent and making part of the, same.

To all, whom Iit may concern:

Be 'it known that I, WILLIAM J oNns, of the city, county, and State of New York, have invented certain new and useful Improvements in Balance Dry-Docks; and I do hereby declare the following to be a full, clear, and exact description thereof, sutlcient to enable those skilled iu the art to which my invention appertains to fully understand and to make and use the same, reference being had to the accompanying drawings forming part of this specification, and in which- Figure 1, sheet l, is a ground plan of a balance dry-dock, showing the gates, bulk-heads, and tanks; Figure 2, sheet 2, represents a transverse section of the dock; and

Figure'3, sheet 3, is a side elevation of one-half of the dock.

Under the old system of raising a balance dry-dock,

with Orwthout avessel thereon, the sinking-gates must be and are kept closed, and 4the whole ofthe water that all the' tanks contain must be pumped out of tanks as the dock rises; and when the dock rol-ls `or lists over to one side, (which is a frequent occurrence, especially in raising ships of very heavy tonnage,) there is no way to restore the equilibrium but by opening the aforesaid sinking-gatesto readmit water, and stopping the machinery on the lighter side, which sometimes causes a delay of several days before a ship can be raised. The cause of this diicultyis the system heretofore practised of pumping out the water from the upper part of the side tanks, where there is a very small space lof' lifting power, and the whole body'ot' water in the lower part of the dock inolines to roll to the heavier side. v

Another diiculty heretofore experienced in raising docks of this class is the bending of the upper portion or sides 0f the dock inward, which is very injurious, not 'only to the dock itself, but also to the ship that is on it, by causing the upper shores, which support the ship 011 either side on even keel, to press with tremendous force against the vessel. This diiiiculty arises from the water being taken ont of the side tanks iirst, leaving the whole weight of the water contained in the central compartments, together with the weight of the ship, restingentirely on the center of the dock, thus straining the latter to such an extent as to make the bottom bend upward at the sides, which necessarily tends to draw the upper vportions vof the side tanks inward toward each other.

lo obviate these difficulties, and thus make vast .and new improvements in the construction of balance dry-docks, is the object of my invention; andA It consists inthe arrangement ofthe central tanks, located wholly beneath the load, and the side tanks, with valves or gates connecting the two sets, said of the pump-well and discharge-orifices, as hereinafter set forth. v

I wilLnow proceed lto describe the invention more fully in detail, referring to the accompanying drawings, wherein similar letters and figures of reference indicate like parts in the several tigures.

In the drawings- A A represent the outside`tanks, which are very high and have the top inclined, as shown in tig. 2. These tanks are of such aggregate capacity as to contain over one-halt` of all the water in the dock when it is sunk, preparatory to raising a ship. l l

B B are the. different compartments or tanks in the central part of the dock. The structure of these tanks, with their relative depth as regards the side tanks, is

' shown onsheet 2.

1 1 1, sheet 1, are the ordinary sinking-gates, which, under the old system, are kept closed while the dock is being raised. y

3 3, 011 sheet 3, represent the discharge-gates or orifices from the pumps.

4 4, sheet 1, represent gates employed to conduct water from the side tanks to the pumps.

5 5, on sheet 1, represent the ordinary gates connectingithecentral end tanks B with the side 'tanks A. These gates do not comeinto use until vthe water in the side tanks is pumped out down to the level of the under sideof the main deck, and it is impossible for the water in the central tanks to run into the side tanks until the water in the latter reaches the aforesaid level. This will be understood from ari-examination of tig. 2.

6 6 are gates by which a portion of the central tanks B communicate with the pumps. shown in tig. l. v

An indicator, S, iig. 2, is employed to show when the ful'llifting power is taken ont ofthe central tanks, and to tell the proper time for closing the gates 6 and the outside delivery-gate, and open the gates 4 when a ship of extra heavy weight .is being raised. 'Ihis indicator consists of a float attached to a small chain.

running over a pulley on the upper deck, with a small weight in the other end to balance the chain. A small perpendicular rod serves as a guide for the oat.

The line of gures marked from 12 to 20 on the side ot` the drawing No. 2 shows the depth of water from the top of the keel-blocks.

In addition to the several series ot' gates above def scribed, which are common in balance dry-docks, I

Ihese gates are partnient's.

provide gates marked 7 7 on sheets 1 and 2, in the cross bnlkheads between the central tanks B, so arranged as to connect all the said tanks together when desired. These gates are operated from the upper deck by means of a toothed wheel working in a rack on aiperpendicular rod, secured at the bottom to a triin the side tanks A to deliver itself freely through` them, and all the sinking-gates 1 1 will be used partially for the same purpose.

Each of the gates 2 2 is so constructed as to deliver as much water as several, say'five, of the ordinary sinking-gates l 1. This is necessary in order to keep the water down in the outside tanks as nearly as possible level with thc water in which the dock is floating, so that there will be no weight of water in the outside tanks to be lifted with the force of the central tanks. t

The dock is sunk by opening al1 the gates 1 l and 2 2,A to admit water to the outside tanks A, whence it flows into the central tanks, the gates 5 being open. The gates 4 4, 6 6, and 7 7 g are all closed while `the dock is sinking.

lVhen about to raise the dock the gates 7 nre all opened, so that the central tanks are connected together, the gates (i are opened so as `to permit the' flow ot' water from the central tanks into the pumpwells, and the gates 5 are closed to sluit off the communication of the side tanks with the central coml`he sinking-gates 1, self-delivery gates 2, and discharge-gates 3, from the pumps, all remain open while raising.

rlhe pumpsbeing now set in motion, water is drawn from the central tanks aud dischargedby way of the gates 3 3. NVater from the side tanks. also flows' out at these gates 3 by its own gravity. As the dock continues to rise, the gates 2 2 gradually appear above the surface ofthe surrounding water, andimmediately begin to discharge large volumes of Awater owin g from the side tanks hyits own gravity. The dock now rises very rapidly, the pumps still continuing to work, and

the gates 3 3, as well as the gates 2, at the same time discharging by gravity. Under these combined influences the sinking-gates 1, which are below the gates 2 2, are soon uncovered, and materially assist the gates 2 2 by discharging water from the lower part of' the dock.

kBy my improvements the whole of the lifting power is transferred from the. outside tanks to the central compartments, upon which the weight of a ship on the dock immediately rests, and consequently there will be an extended area of lifting space directly under the ship, which gives the dock the full lifting power at once, whereby the dock is raised very rapidly, the water at the same time forcing itself` out from all the outside tanks through the new self-delivery gates, and partially through the sinking-gates and the dischargeorices 3, asfabove described.

This self-discharging feature is very important, in view of the fact that hitherto all the wat-er had to be raised and thrown ont b'y pumps, whichis a` much slower, and consequently more expensive mode of raising a dry-dock.

It will also be seen that, by the provision of the gates 2 2, which are always open, the waterin the side tanks heilig nearly on a level with the water on the outside ofthe dock, it will be utterly impossible for the dock to. roll. v

Having tlnls described my invention,

Whatl claim as new, and desire to secure by Letters Patent, is-

1. A balance dry-dock, constructed with central tanks B B, separated by bulkheads, iu which are gates 7 7, side tanks A A, connected` with the central tanks by gates o 5, the self-delivery gates 2 2,

pump discharge-orifices 3 3, and sinking and self-de Witnesses HENRY W. CLARK, Hormon BARNARD.

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