Structural Improvements in Iron and Steel Vessels.
Year: 1891

page_text: Date of Application, 22nd Dec., 1891
Complete Specification Left, 21st Sept., 1892-Accepted, 29th Oct., 1892
PROVISIONAL SPECIFICATION.
Structural Improvements in Iron and Steel Vessels.
I WILLIAM BELL of Camperdown Shipyard, Dundee in the County of Forfar,
North Britain, Naval Architect do hereby declare the nature of this invention
to be as follows, that is to say :-
My said invention has for its object to improve and simplify the construction
of parts of the framing and plating of vessels built of iron or steel.
In carrying out my invention in vessels of cellular type I space the transverse
frames within the range of the double bottom or for the entire, or any part, of the
length of the vessel, to the height of the double bottom at the same or nearly the
same distance apart which is now customary in ships of similar size and class. I
maintain this spacing by preference outside the double bottom to the height of the
upper turn of bilge. From this point to the upper deck height I increase the
transverse frame spacing to double or more than double the frame spacing below
and continue the wider spacing fore and aft for the entire length, or any part of the
vessel's length that may be desired. These side frames are increased in depth of
web or otherwise strengthened to maintain sufficient rigidity in conjunction with,
and assisted by, longitudinal framing. The longitudinal framing, I carry along
the sides attached to the frames and skin plating in the form of modified keelsons
and spaced vertically at about the distance apart which would make the area of
unstiffened plating, at any part, the same or nearly the same as would be secured
with transverse framing of the usual spacing.
The longitudinals are formed by a combination of steel or iron bars of various
sections so disposed as to form a light continuous girder horizontal framing in
conjunction with, & connected to, the transverse framing. The shell plating or
most of it is of uniform thickness. The bottom strakes to turn of bilge may be
lap jointed in the usual manner. From the bilge to the upper deck the strakes
are flush at their edges butting on the flanges of the longitudinals and connected
by continuous horizontal straps outside. The vertical butts may be strapped in a
similar manner to the seams or flush with strap inside. I make the beam ends by
preference without knees, securing them to the frames by a novel combination of
plates and bars.
In double bottom ships I form the floors on the lattice girder principle used in
bridge building. In vessels without a double bottom I construct the floors and
bottom substantially in accordance with present practice, but at the sides resort to
the modification herein before described for vessels of cellular form.
Dated this Twente-first day of December 1891.
COMPLETE SPECIFICATION.
Structural Improvements in Iron and Steel Vessels.
I, WILLIAM BELL, of Camperdown Shipyard, Dundee, in the County of Forfar,
North Britain, Naval 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, that is to say :-
My said invention has for its object to improve and simplify the construction
of parts of the framing and plating of vessels built of iron or steel.
In carrying out my invention in vessels of cellular type I space the transverse
D

page_text: frames within the range of the double bottom for the entire or any part of the
length of the vessel, to the height of the said double bottom, at the same or nearly
the same distance apart which is now customary in ships of similar size and class.
I maintain this spacing by preference outside the double bottom to the height of
the upper turn of bilge. From this point to the upper deck height, I increase the
transverse frame spacing to double or more than double the frame spacing below
and continue the wider spacing fore and aft for the entire length or any part of
the vessel's length that may be desired. These side frames are increased in depth
of web or otherwise strengthened to maintain sufficient rigidity in conjunction with
and assisted by, longitudinal framing. The longitudinal framing, I carry along
the sides attached to the frames and skin plating in the form of modified keelsons
or girders having the skin for outer flange, and spaced vertically at about the
distance apart which would make the area of unstiffened plating at any part, the
same or nearly the same as would be secured with transverse framing of the usual
spacing. The longitudinals are formed by a combination of steel or iron bars of
various sections so disposed as to form a light continuous horizontal girder framing
in conjunction with and connected to the transverse framing. The shell plating or
most of it is of uniform thickness. The bottom strakes to turn of bilge may be
lap jointed in the usual manner.
From the bilge to the upper deck the strakes are flush at their edges butting
on the flanges of the longitudinals and connected by continuous horizontal straps
outside. The vertical butts may be strapped in a similar manner to the seams or
flush with strap inside. I make the beam ends by preference without knees, securing
them to the frames by a novel combination of plates and bars. In double bottom
ships I form the floors on the lattice girder principle used in bridge building. In
vessels without a double bottom I construct the floors and bottom substantially in
accordance with present practice, but at the sides resort to the modification herein-
before described for vessels of cellular form..
And in order that my said invention' may be properly understood; I now proceed
more particularly to set forth the system, mode, or manner in or under which the
same is or may be used, or practically carried into effect, reference being made to
the accompanying drawings, and to the letters and figures marked thereon, that is
to say :-
Figure 1. is a transverse sectional elevation at midships' of a portion of a vessel
showing part of the bottom and side, the other part of the section being illustrated
on Sheet 2.
Figure 2. is a longitudinal section through A. A. (Figure 1.) of a part of the
bottom framing of the vessel.
Figure 3. is a sectional plan at B. B. (Figure 1.) of a part of one of the side
girders.
Figure 4. is an alternative transverse section of the side girders, and longitudinal
butt joint.
Figure 5. is a transverse sectional elevation at midships of the upper portion of
a vessel showing the side and beams. Note:-The dotted part at c. (Figure 1.) is
repeated at D. (Figure 5.) in order to show the connection between the two
illustrations, the combination giving a transverse half sectional elevation of the
frame of a vessel.
Figure 6. is a sectional plan at E. E. (Figure 5.) showing the method of connecting
the stringer plate with the shell and frames.
Figure 7. is a transverse sectional elevation of a portion of a vessel showing an
alternative method of constructing the bottom framework to that illustrated in
Figures 1. and 2. and of the method of constructing the bulkheads.
Figure 8. is a longitudinal section through G. G. (Figure 7.) of a part of such
alternative method.
Figure 9. is a sectional plan at H. H. (Figure 7.) showing the method of
connecting the bulkheads to the side girders of the vessel.
Figure 10. is a longitudinal section at I. I. (Figure 7.) of the bulkhead.

page_text: Figure 11. is a side elevation of a part of the shell of the vessel looking from J.
(Figure 12.) with the bulb angle 36, removed showing the method of joining the
plates by means of a vertical butt strap.
Figure 12. is a sectional plan at K. K. (Figure 11.) of the aforesaid butt joint.
Figure 13. is a side elevation of a part of the shell of the vessel looking from L.
(Figures 14.) with the bulb angles 36. removed showing the method of joining the
plates by means of a lapjoint.
Figure 14. is a sectional plan at M. M. (Figure 13.) of the aforesaid lapjoint.
Figure 15. is a transverse sectional elevation showing how my method of
construction may be used to ventilate a vessel.
Figure 16. is a part plan of the vessel, further illustrating my method of
ventilation.
Figure 17. is the corresponding longitudinal sectional elevation of same.
I will now more particularly describe the various novel methods I adopt in the
construction of a vessel, according to my invention.
In Figure 1, the centre-through-plate 18. has riveted to it two angle steels or
irons 19, hereinafter referred to as angles, of such sectional area as to form a keel
of strength sufficient for the vessel. The flanges of such angles are of heavier
section where riveted to the plate 18, than those riveted to the garboard strakes 20.
I propose to use such sections of angles or tees, that is to say of different thicknesses
of flanges, in the construction of other portions of vessels. In Figures 1. and 2.
the construction of the cellular bottom or tank of the vessel is illustrated. Each
transverse girder consists essentially of angles 21. and 22. forming the bottom and
top booms respectively of the girder, and attached to the centre-through-plate 18.
by means of the flanged plates or broad angles 23, their other extremities being
attached to the tank wing plates 24,-which are flanged as shewn at 47. and so
attached to the bilge strake-by flanged plates or broad angles 25. These booms
are connected to the bottom strakes and to the tank top plates in the usual manner;
In the
and are otherwise suitably supported by the intercostals 26. and struts 27.
alternative method of constructing the bottom as illustrated by Figures 7. and 8.
a channel iron 28. is substituted for the angle 21. the intercostals 29. being also of
channel section. The shearing stress in the girder is provided for by struts and
ties 30, or in any other known way.
The sides of the vessel are constructed in the manner shewn in Figures 1. 3. 4. 5.
6. 11. 12. 13. and 14, in which 31. are the intercostal longitudinals, and 32. the
frames.
The plates are jointed longitudinally by means of the butt straps 33, as shewn,
the vertical joints 34. and 35. being either butt or lap as found most desirable.
It should be pointed out that I have designed all the butt joints in such a manner
that the rivets are in double shear, and that vibration is prevented by an inner
strap of T section, and the rivetting of both systems of vertical joints is supple-
mented by longitudinal Tirons 52.
The intercostals 31. are bound together by the continuous longitudinal bulb
angles 36, which form in combination with the skin of the vessel inner and outer
members respectively of the longitudinal girders 31.
In Figures 5. and 6. it is shown how the beams F. are attached to the frames 32,
and the stringer plates 37. to the intercostals 38. and stringer angle 39.
The bulkheads are constructed as shewn in Figures 7. 9. and 10, from which it
will be seen that the plates 40. are of channel section and are stiffened by means
of transverse angles 41. The top and bottom series of plates 42. are flanged and
riveted to the angles 41, and also riveted to the beams and Ts 43. The bulk-
heads are attached to the frames 32. by the plates 44. Where the bulb angles 36.
pass the bulkheads, collars 45. are used, in order to make the space watertight.
At 46. are shewn the bulb angles 36. with such collars removed.
The method adopted for ventilating the interior of the vessel is shown in
Figures 15. 16. and 17. in which 48. are the main ventilating shafts, forming part
of the bulkheads, thus helping to stiffen same. Branch pipes 49. conduct the fresh

page_text: air to the sides of the vessel as shewn by the arrows, its free circulation being
provided for by the holes 50. in the frames and longitudinal intercostals, the foul
air escaping through the exits 51.
The advantages which accrue from my system of construction over the ordinary
style are many and various, as for example :-
(1) A reduction in the cost of construction.
(2) An increase in deadweight capacity with the same displacement is obtained
without appreciable reduction in scantlings or loss of strength, by a better and
more economical disposal of the available material and also by a reduction in
weight of bottom cement which has not to be carried up to protect the frame
rivets, because, by using the angle or channel steels or irons 21, 28, no horizontal
rivets are required, and further, the usual cementing of the chocks at each side
stringer and in way of each deck between the frames is dispensed with, because of
the system of ventilating rendering this unnecessary.
(3) An increase in stowage capacity according to the nature of the cargo to be
carried.
(4) A considerable saving in dunnage and cost of stevedoring.
(5) An increased weight of water ballast with double bottom of the same
external dimensions.
(6) Greater facilities for cleaning tanks and sides.
(7) A great saving in cost of repairs if damaged.
(8) An efficient system of hold ventilation whereby sweating is prevented, and
the durability of the vessel internally is much increased, a system which cannot be
carried out in vessels built on the ordinary transverse principle.
(9) A. reduction in gross register tonnage owing to the increased depth of the
side frame girders.
(10) By using angle or channel steels or irons 21, 28, increased strength is
obtained for the resistance of local strains.
Having now particularly described and ascertained the nature of my said
invention and the system, mode, or manner in or under which the same is or may
be used or practically carried into effect, I would observe that I do not claim the
method of, and means for ventilating ships, but that the drawings accompanying
this Specification are merely intended as an illustration of the scope of the design
when fully carried out, and not as a restriction to the particular arrangement shewn,
which would most likely vary in almost every vessel according to circumstances,
but what consider to be novel and original and therefore claim as the invention
secured to me by the hereinbefore in part recited Letters Patent is :-
In the construction of ships or vessels,
(1) The improved system, mode or manner in or under which the same is or may
be used or practically carried into effect, as hereinbefore described and shewn in
the accompanying drawings.
(2) The method of constructing the keel of two angles riveted to the centre-
through-plate, the flanges of the angles being of different thicknesses, substantially
as herein before described and illustrated in the accompanying drawings.
(3) The system adopted in the construction of the transverse and longitudinal
bottom girders, the tank wing plates and the shell, substantially as hereinbefore
described and illustrated in the accompanying drawings.
(4) The system adopted in the construction, arrangement, and spacing of side
framing and beams, substantially as hereinbefore described and illustrated in the
accompanying drawings.
(5) The longitudinal shell plate butt joint, as herein before described and
illustrated in the accompanying drawings.
(6) The vertical shell plate butt joint as herein before described with reference
to Figures 11. and 12.
(7) The vertical shell plate lap joint as herein before described, with reference to
Figures 13. and 14.

page_text: (8) The method of joining the beams F. to the side frames as herein before
described and illustrated in the accompanying drawings.
(9) The system and combination of channel and angle steels or irons adopted in
the construction of the bulkheads as hereinbefore described and illustrated in the
accompanying drawings.
(10) The employment of sections of metal having flanges of different thicknesses
which may be combined to form girders lighter than if the flanges were of equal
thickness, as described.
Dated this 19th day of September 1892.
GEO. C. DOUGLAS & Co.,
41, Reform Street, Dundee, Agents for Applicant.