Improvements in Dry Docks.
Year: 1897

page_text: Improvements in Dry Docks.
I, ALFRED DUwoos, of 32, Rue Centrale, Rouen, France, Inventor, do hereby declare
the nature of my invention to be as follows:-
The present invention concerns an automatic swing-dock intended for flat bottomed
boats for executing the necessary repairs.
This dock may be constructed in any dimension so as to be able to bear boats of
any tonnage and it is composed of vertical piles sunk into the ground and arranged
in 3 longitudinal rows, so that the middle row is at an unequal distance from the two
exterior rows.
The piles are coupled two by two and are successively connected in each longi-
tudinal row by squared pieces of wood assembled with the upper part of the piles;
moreover these pieces of wood are connected transversely by cross-pieces coupled
two by two and fixed at their middle and ends upon the longitudinal pieces.
Each pair of cross-pieces bears on its upper face above the piles of the middle row,
the fixed part of a swivel joint the movable part of which is fixed upon the lower
face of a transverse support.
The transverse support intended to receive the boat also the cross-piece, are thicker
at their middle than at their ends, moreover the transverse supports are each formed
of two iron cheeks into which wood pieces are fitted. These two cheeks are connected
together by means of cross-bolts and in such a way as to have between them an
empty space for the passage of an upright terminated at its lower part by an extension
sliding in the slide and which can be drawn more or less towards the center of the
dock and held by means of a pin passing through holes made in the sides of the
crosspiece, 20 centimeters apart.
The transverse supports are held horizontally by means of iron rods or claws which
enter the grooves and are provided at their upper threaded extremities, with a nut
serving to fix the movable cross-pieces in the desired position; moreover pieces
fixed on the piles and the longitudinal pieces are jointed to the lower extremities of
the claws so as to be able to disengage these latter from the movable transverse
supports by dropping them along the piles.
For the working of the dock two of the movable cross-pieces called the commanding
cross-beams have no claws and are provided with drawing screws which are composed
of an iron rod threaded and provided with a nut at its upper part and connected in
the same way as the claws at its lower end; this rod passes through a transverse
socket terminated by two pivots turning in a cast iron support fixed to the extremity
of the commanding cross-beam by means of bolts.
The rods allow the dock to adopt the desired inclination but the dock can of its own
accord assume this inclination; for this purpose the transverse supports are eccentric
with respect to the swivels so that one side of the dock is heavier than the other.
This dock must be constructed in such a way as to be able to dock full-tide boats
during the lowest summer tides, however by means of pieces of wood to be fixed
upon the transverse supports by utilizing the holes intended for the uprights, the level
of the dock may be raised according to necessity during swells or high-tides.

page_text: Each pair of cross-pieces D bears on its upper face above the piles B of the middle
row, the fixed part C of a swivel joint the movable part of which is fixed upon the
lower face of a transverse support H.
The transverse support H intended to receive the boat also the cross-pieces D, are
thicker at their middle than at their ends, moreover the supports H are each formed
of two iron cheeks into which wood pieces are fitted. These two cheeks are connected
together by means of cross-bolts and in such a way as to have between them an
empty space a for the passage of an upright I terminated at its lower part by an
extension sliding in the slide a and which can be drawn more or less towards the
centre of the dock and held by means of a pin passing through holes b made in the
sides of the cross-piece H, twenty centimeters apart.
The supports H are held horizontally by means of iron rods or claws J which enter
the grooves a and are provided at their upper threaded extremities, with a nut serving
to fix the movable cross-piece H in the desired position Figs. 3, and 5; moreover
pieces & fixed on the piles B and the longitudinal pieces A, are jointed to the lower
extremities of the claws J so as to be able to disengage these latter from the movable
cross-pieces H by dropping them along the piles.
For the working of the dock two of the movable cross-pieces H called the
commanding cross-beams have no claws and are provided with drawing screws K,
Figs. 4, and 6, which are composed of an iron rod f with a thread and a nut at its
upper part and connected in the same way as the claws at its lower end; this rod f
passes through a transverse socket g terminated by two pivots turning in a cast iron
support fixed to the extremity of the commanding cross-beam by means of
bolts.
The rods K allow the dock to adopt the desired inclination but the dock can of its
own accord assume this inclination; for this purpose the movable cross-beams H
are eccentric to the swivels E, C, so that one side of the dock is heavier than the
other.
This dock must be constructed in such a way as to be able to dock full-tide
boats during the lowest summer tides however by means of pieces of wood to be fixed
upon the cross-beams H by utilizing the holes intended for the uprights I,
the level of the dock may be raised according to necessity during swells or high
tides.
The swing-dock can be utilized not only in places where the water-level varies
according to the effect of the tide, but also on all canals and sluice-rivers, for
this purpose it suffices to construct the framing in a dock whose entrance is a
head of the sluice and which can be emptied by means of sluices in the down
stream.
The way of employing this dock is very simple and easy to understand; the cross-
beams H being previously fixed and kept horizontally by means of the claws J the
boat at high tide is brought above the dock and firmly moored to the uprights I; at
low tide the boat is grounded upon the dock.
If the bottom of the boat must be examined or repaired the claws J on the side
opposite to that on which the boat must lean are set free, and at low tide the boat
adopts the position shown in Fig. 4. When the boat cannot be swung by the tide
this operation is made by means of the drawing-screws K.
If the movable cross-beams H must be displaced these cross-beams are supplied
at the points where the boat rests with hard corner blocks fixed to the cross-beams
At low tide the
by means of cramps and the boat is docked as explained before.
boat is propped on each side of the cross-beams to be moved, the corner blocks are
removed and the cross-beams H are slipped on the fixed part C of the swivels.
on the
When the repairs are finished the boat is set afloat either with the high tide or
without it by swinging the dock by means of the drawing screws
floating side after having firmly fastened the boat to the cross-beams H of the
opposite side.
By removing the uprights I and running the chains, the boat owing to the slope of
the dock will slide out of its own accord.