Improvements in Dry Docks.
Year: 1890

page_text: COMPLETE SPECIFICATION.
Improvements in Dry Docks.
I OEHLMANN VON NERTA of Washington, in the District of Columbia, United
States of America, Architect, do hereby declare the nature of this invention and in
what manner the same is to be performed, to be particularly described and ascertained
in and by the following statement :-
This invention relates to that class of dry docks known as "permanent dry docks,"
which are located in proximity to a water way or harbor, the objects of the invention
being to improve the construction of the bottom and sides, whereby the drainage is
greatly facilitated, and also to provide an improved mechanism for centring the vessels
and retaining them firmly in upright position.
To the above ends the invention consists in certain novel details of construction and
combinations and arrangements of parts to be hereinafter described, and pointed out
particularly in the claims at the end of this Specification.
Referring to the accompanying drawings
Figure 1 is a sectional view through a dock constructed in accordance with my
invention.
Figure 2 is an enlarged section of a portion of one side.
Figure 3 is a similar view showing the flooring and drains on an enlarged scale.
Figure 4 is a perspective view of a section of the flooring, with different portions
broken away to show the construction.
Similar letters of reference indicate the same parts in all the figures.
In constructing a dock in accordance with my present invention, where the soil is
soft or yielding piles are driven in rows the desired distance apart over the entire area
of the bottom of the dock, and therefore gauged by the size of the latter, and on the
tops of these piles (lettered A,) are fastened by pins, spikes, or drift-bolts the cross-
timbers or joists B, extending from side to side of the bottoin of the dock. Where,
however, the soil in which the dock is formed is hard or rocky, of course the timbers B
may be laid without the piling, either on the ground itself or on any suitable founda-
tion adapted to bear the weight of the superposed structure.
The top level of the timbers B determines the slope or inclination of the bottom of
the dock, which should be somewhat lower at one end than at the other, in order that
the drainage may be properly collected in a suitable cistern, pump-well, or other
receptacle for removal."
On top of the cross-timbers B is laid what I term a "drain-flooring," running
longitudinally or from the highest to the lowest level of the bottom of the dock. By
drain-flooring I mean a flooring having in its upper surface a series of drains or grooves
which open directly into the cistern or pump-well or into larger drains which lead into
the same.
In the preferred construction, and as shown in the drawings, said flooring is con-
structed of alternate sections of relatively thick and thin planking C and D, respec-
tively secured in position by spikes or drift-bolts and matched or connected by grooves
and tenons, as shown, to form a water tight floor, the whole being then covered with
a heavy coat of elastic cement or asphaltum E. (see Fig. 3).

page_text: This drain-flooring in turn supports the flooring proper or wearing-surface F,
composed of planking laid transversely of the drains with a narrow space between
each plank to permit of the passage of water into the drains.
At the sides of the bottom flooring are. large drains H, the bottoms of which are
below the level of the under surface of the drain-flooring and passages G lead from
below the said flooring into the drains, suitable flap-valves 9 being provided to prevent
any water passing out through said passages, but permitting of its free entry, in order
to relieve the hydrostatic pressure, which, as is well known, might otherwise injure
the bottom flooring, and further by draining the substrata preventing the entrance of
water at the sides of the dock.
The sides of the dock are, as usual, formed by a series of wide steps or platforms
commonly termed "altars," the rises in the present instance preferably being formed
by rows of piles a and the altars or horizontal portions similar to the flooring just
described, the drains or grooves running from the highest to the lowest end and
opening into the cistern or pump-well, as before mentioned. The cross, timbers or
joists B₁ of the altars are supported by horizontal strips or girts B2, spiked or other-
wise secured to the faces of the adjacent rows of piling. In the bottom of the dock
are located the usual keel blocks or supports I, and on each side of the same are
pivoted timbers L, which swing in vertical planes and are adapted to rest against and
support the hull of the vessel to prevent any tilting movement, as well as to centre
the same as the water is withdrawn.
In order, now, to elevate the timbers or supports L, double-toggle levers M, N, O, P,
are provided, pivoted at one end to a block in the bottom of the dock or directly to
the floor-timbers, a screw-rod N¹ passing through both of the toggle-joints and having
nuts S, T, on the outside, serving to hold the toggles together and the timbers
elevated.
When the water is in the dock, the timbers are elevated by steel-wire ropes or
cables connected to the lower toggle-joints and operated by any suitable windlass or
winding-drum at the side of the dock.
The operation is as follows: A vessel to be repaired istowed into the dock, the gate.
or dam closed, and the water withdrawn until the vessel rests on or is in proximity to
the keel-blocks, when the supports L are elevated by means of the cables and toggle-
joints and held firmly in contact with the bottom of the vessel while the remainder of
the water is withdrawn, the vessel meanwhile being held in upright position by the
supports, which are prevented from injuring the hull by means of pads K of any pre-
ferred construction.
After the water is removed the nuts S, T, are set up, drawing the toggles firmly
together and holding the vessel in an absolutely rigid cradle, which may be easily
adjusted to incline the vessel to one side or the other or to straighten the same.
No water can remain on the top surface of the floor, and any rain or water entering
from the sides will be caught either in the bottom or on the altars and at once con-
ducted to the cistern or pump-well for removal.
The draining of each separate altar, it will be noted, prevents any water from
running down into the bottom of the dock; hence preventing any side washing, to say
nothing of the ease with which the sides may be formed, the accumulation of slippery
substances and water being entirely prevented.
As it is obvious that the outer floor may be made of removable pieces in order to
permit of access to the drains for cleaning, as well as to renew the floor, I have not
deemed it necessary to illustrate the same, but do not wish to be limited to the rigid-
form shown.
Having now particularly described and ascertained the nature of my said inven
tion, and in what manner the same is to be performed, I declare that what I
claim is:
1. In a dry-dock as described, the combination, with the cross timbers or joists,
of the water-tight drain-flooring resting thereon and having the longitudinal drains or
grooves in its upper surface leading to the cistern or pump-well, and the flooring on

page_text: said drain-flooring having openings therein through which the water may pass,
substantially as described.
2. In a dry-dock, as described, the combination, with the cross timbers or joists, of
the drain flooring resting thereon, composed of the relatively thick and thin planking
jointed together and forming drains or grooves in the upper surface, and the wearing-
floor resting on said drain-floor and composed of slightly-separated planks, sub-
stantially as described.
3. In a dry-dock, as described, the combination, with the cross timbers or joists, of
the drain-flooring resting thereon, composed of the relatively thick and thin planking
jointed together to form drains in the upper surface, the coating of elastic cement on
said drain-flooring, and the wearing floor resting on said drain-floor and composed of
slightly separated planks, substantially as described.
4. In a dry-dock, the combination, with the water-proof flooring, of the drains at
the sides, extending below the under surface of the floor, and the openings leading
from beneath the floor into said drains, substantially as described.
5. In a dry-dock, the combination, with the water-proof flooring, of the drains at
the sides, extending below the under surface of the floor, the openings leading from
beneath the floors into said drains, and the flap-valves for preventing the passage of
water out through said openings, substantially as described.
6. In a
dry-dock, the combination, with the bottom floor, of the altars having
the rises formed by rows of piles and the horizontal portions resting thereon, sub-
stantially as described.
7. In a dry-lock, the combination, with the bottom floor, of the altars having the
rises formed by rows of piles, the girders secured thereon, and the horizontal portion
carried by said girders, substantially as described.
8. In a dry-dock, the combination, with the bottom floor, of the altars having the
longitudinal drains therein for catching the water and carrying the same to the
cistern or pump-well, substantially as described.
9. In a dry-dock, the combination, with the bottom floor having the longitudinal
drain, of the altars having the cross-timbers, the drain-flooring resting thereon and
composed of the relatively thick and thin planking forming longitudinal grooves,
and the wearing-floor resting on said drain-flooring, substantially as described.
10. In a dock, the combination, with the pivoted supporting timbers, of a cable
for elevating said timbers to support the vessel as the water is withdrawn, substantially
as described.
11. In a dock, the combination, with the pivoted supporting-timbers, of a toggle
connected thereto, and a cable for operating said toggle to elevate the timber and
support the vessel while the water is being withdrawn, substantially as described.
12. In a dock, the combination, with the pivoted supporting-limbers, of toggles
connected thereto, and a screw for holding said toggles and timbers in adjusted
position, whereby a rigid cradle may be formed, substantially as described.
13. In a dock, the combination, with the pivoted supporting-timbers, of double
toggles connected thereto, a cable for operating said toggles, and a screw connecting
said toggles for holding the same in adjusted position, substantially as described.
14. In a dock, the combination, with the keel-block and the supporting-timbers
pivotally connected thereto on each side, of the double-toggle levers pivoted at one
end to the timbers and at the opposite end to the bottom of the dock, the screws con-
necting the toggles of each pair, and the nuts on the ends of the screws, substantially
as described.
F. W. BARKER,
Applicant's Agent..