Improvements in Ships and other Structures of Metal Plates Rivetted together.
Year: 1888

page_text: Improvements in Ships and other Structures of Metal Plates
Rivetted together.
We, WALTER HENRY WILSON, and WILLIAM JAMES PIRRIE, of Queens Island,
Belfast, Shipbuilders, do hereby declare the nature of this invention to be as
follows:-
This invention has for its object to provide an improved form of connection for the
butts or transverse joints of ships shell plating, deck plating, ballast tank tops,
bulkheads and other plated structures, which is stronger, more easily caulked water-
tight and less likely to be strained than the usual connection with either single or
double straps or the ordinary form of lapped butts with liners in the longitudinal
seams.
The improved connection is formed by setting inwards to a suitable angle one end
of each plate and by setting outwards the other end of the adjoining plate and lapping
the one over the other in such a manner that when the plates are rivetted together
any longitudinal strain to which they may be subjected will pass through the centre
of resistance of the connection without having a tendency to distort the connection
and start the rivetting as is found to be the case in the ordinary butt joints with
single straps. To avoid the necessity of putting in liners or tapered filling pieces in
the longitudinal seams and also to allow of these seams being worked to a fair curve
or straight line as the case may be, we plane or otherwise cut away to a fair taper and
to a feather edge the parts of the transverse lapped butts where they extend under the
longitudinal seams. The part tapered away extending only for a breadth equal to
that of the longitudinal seam and the length of the taper being equal to the length of
the transverse lap. The inner edges of the tapered parts of the plates are planed
square and the edge of the strake of plating next above or next below butts against
this forming joints which can be easily caulked.
Dated thie 2nd day of Anvil 1888

page_text: Rivetted together.
We, WALTER HENRY WILSON, and WILLIAM JAMES PIRRIE, of Queens Island,
Belfast, Shipbuilders, 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 has for its object to provide an improved form of connection for the
butts or transverse joints of ships shell plating, deck plating, ballast tank tops, bulk-
heads and other plated structures, which is stronger, inore easily caulked watertight
and less likely to be strained than the usual connection with either single or double
straps or the ordinary form of lapped butts with liners in the longitudinal seams.
The improved connection is formed by setting inwards to a suitable angle one end
of each plate and by setting outwards the other end of the adjoining plate and lapping
the one over the other in such a manner that when the plates are rivetted together
any longitudinal strain to which they may be subjected will pass through the centre
of resistance of the connection without having a tendency to distort the connection
and start the rivetting as is found to be the case in the ordinary butt joints with single
straps. To avoid the necessity of putting in liners or tapered filling pieces in the
longitudinal seams and also to allow of these seams being worked to a fair curve or
straight line as the case may be, we plane or otherwise cut away to a fair taper and to
a feather edge the parts of the transverse lapped butts where they extend under the
longitudinal seams. The part tapered away extending only for a breadth equal to
that of the longitudinal seam and the length of the taper being equal to the length of
the transverse lap. The inner edges of the tapered parts of the plates are planed
square and the edge of the strake of plating next above or next below butts against
this forming joints which can be easily caulked.
In order that our said invention may be fully understood and readily carried into
effect we will proceed to describe the drawings hereunto annexed.
DESCRIPTION OF THE DRAWINGS.
Figures 1 and 1* are side views of different parts of the structure Figure 2 is a
D
Th

page_text: between the plates c and the frames or beams a a. eee are rivets fastening the parts
a b and c together; el e¹e are rivets fastening the parts a, c and d, and ³ ³ ³ are
rivets fastening the parts a and b.
In each strake where the plates meet in a transverse joint they overlap and the ends
are beut in and out so that the joint becomes symetrical about a centre line drawn as
in Figure 2 at xx. Then tensile strain being in the direction of the line has no
tendency to deform the joint. ff are rivets fastening the over lapped plates 6 and c
in the transverse joints.
Where the strakes overlap and are jointed together and where a transverse joint
comes into the longitudinal joint, the corner which would otherwise prevent the
strakes meeting with fair surfaces is removed as is shown at the parts marked 9 g.
The rivets marked hh simply fasten a plate of one strake to a plate of another whilst
the rivets h¹¹ at the cross joint pass through two plates in one strake and one plate
of the other strake. Figure 6 further shows the form in which the corners of the
plates are cut away; this may be done by planing or otherwise. In this manner very
strong and tight work may be produced in a simple way and without the insertion of
small pieces in the joints between the plates.
Having now particularly described and ascertained the nature of our said inven-
tion and in what manner the same is to be performed we declare that what we
claim is :-
The structure substantially as described consisting of frames or beams with plates
rivetted together and to the said frames or beams in strakes crossing the frames or
beams transversely, alternately an inner and an outer strake, and so overlapped and
jointed together end to end that tensile strain has no tendency to deform the joint,
and the strakes lapped and jointed together with a continuous fair surface between
them produced by cutting down the corners of the plates to a feather edge where
longitudinal and transverse joints meet.