Improvements in or relating to Bulk Cargo Vessels.
Year: 1892

page_text: Date of Application, 16th Nov., 1892
Complete Specification Left, 1st July, 1893-Accepted, 5th Aug., 1893
PROVISIONAL SPECIFICATION.
Improvements in or relating to Bulk Cargo Vessels.
I, CHARLES DAVID DOXFORD of Pallion Ship-yard, Sunderland, in the County
of Durham, Ship-builder, do hereby declare the nature of this invention to be as
follows:-
-
This invention relates to vessels adapted to carrying bulk cargoes, particularly
grain, and I will describe the invention as applied to a vessel for carrying grain in
bulk.
Owing to the settling of the cargo it is necessary that means should be provided
for supplying the deficiency and maintaining the level of the grain which is lost by
the settling of the cargo. This is effected by constructing the hatchways, of such
capacity as to contain two per cent. of the amount of the cargo; the shrinkage due
to settling having been found to equal two per cent. of the cargo. Another
difficulty that has to be provided against is the shifting of the cargo in a seaway,
to prevent which, what are known as shifting boards, usually loose temporary
boards, are employed, to divide the grain into separate portions or sections, these
boards being arranged as a central longitudinal bulk head or division throughout the
cargo holds. I find that by the construction I am about to describe I can dispense
with the shifting boards or longitudinal bulkhead while providing for the settling
of the cargo and prevent the shifting of the grain. The invention may be carried
out as follows:-
The hull may be constructed of any suitable or usual form, preferably such as is
described in my previous Specification No. 16516 of 1891, and at its upper and
central portion, at or about the place usually occupied by the deck, I form an
extended or extra cargo space adapted to contain a suitable proportion of the grain
(say conveniently 10 per cent. thereof if the cargo be wheat-in the case of oats
for example a larger proportional space might be required to sink the vessel to her
proper load line), and upon this I place the hatch-ways which may be constructed
to contain the usual shrinkage provision of 2 per cent. This extended or extra
cargo space I prefer to form by carrying the side walls above what would
usually be the deck level, and in cross section I prefer that it should
extend to more or less-about one-third of the total breadth of the vessel,
the height of it being such as is necessary to contain the desired quantity of the
grain. It will be understood that the precise quantity of grain contained in this
extra space may vary but it is important that the quantity should bear such
relation to the total quantity of the cargo as will cause the total shifting of the grain
to be confined to this particular space, the breadth and height of the extra space
being so arranged that no ordinary heeling over of the vessel would enable a line
representing the then top or surface of the grain to clear what I may call the
connecting point between the deck and the wall of the extra space, the result of
such an arrangement being that while the grain in this relatively small or narrow
space may shift with the movement of the vessel, the bulk of the cargo below does
not shift and consequently the stability of the vessel is not appreciably interfered
with.
Regarding the hatch-ways to contain the usual 2 per cent. for shrinkage it should
be understood that these may or may not extend to a less distance across the vessel
than the previously referred to extra space, but for convenience and some
advantages in the working of the vessel it is preferred to make the breadth of
the hatch-ways materially less than that of the extra space, partly for convenience
in passing along beside the batch-ways, partly to prevent the seas from striking the

page_text: hatch-way combings with the same force and effect that they might do if these
were extended to the outside of the extra space; but it will be understood that,
taking the extra space and the hatch-ways as containing between them the
necessary proportion of the total cargo, the effect, so far as the non-shifting of
the grain and the provision against shrinkage are concerned, could be attained by
carrying up the walls of the extra space so as to form the hatchways.
Although, as above stated, this construction may be applied to vessels of
ordinary form, I nevertheless prefer the form described in the above referred
to Specification No. 16516/91, particularly, on account of the rounded gunwale
therein described, as with that form the grain readily fills up the main portion of
the hull without leaving empty corners which might occur with a sharp angle
unless special means were provided either to fill up those corners or to prevent
shifting of the cargo there by the provision of shifting boards which I prefer to
dispense with altogether.
It will be understood that if desired any ordinary arrangement of the shifting
boards or longitudinal bulk-heads may be employed but that they are not essential
and I prefer to dispense with them; the usual thwartship bulk-heads may however
with advantage be employed.
Dated this 15th day of November 1892.
W. P. THOMPSON & BOULT,
Agents for the Applicant.
COMPLETE SPECIFICATION.
Improvements in or relating to Bulk Cargo Vessels.
I, CHARLES DAVID DOXFORD, of Pallion Ship-yard, Sunderland, in the County
of Durham, Ship-builder, do hereby declare the nature of the said 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 vessels adapted to carrying bulk cargoes, particularly
grain, and I will describe the invention as applied to a vessel for carrying grain in
bulk.
Owing to the settling of the cargo it is necessary that means should be provided
for supplying the deficiency and maintaining the level of the grain which is lost by
the settling of the cargo. This is effected by constructing the hatchways of such
capacity as to contain two per cent. of the amount of the cargo; the shrinkage due
to settling having been found to equal two per cent. of the cargo. Another
difficulty that has to be provided against is the shifting of the cargo in a sea-way,
to prevent which, what are known as shifting boards, usually loose temporary
boards, are employed, to divide the grain into separate portions or sections, these
boards being arranged as a central longitudinal bulk-head or division throughout
the cargo-holds. I find that by the construction I am about to describe, I can
dispense with the shifting boards or longitudinal bulkhead while providing for the
settling of the cargo and preventing the shifting of the grain. The invention may
be carried out as follows:-
The hull may be constructed of any suitable or usual form, preferably such as is
described in my previous Specification No. 16516 of 1891, and at its upper and
central portion, at or about the place usually occupied by the deck, I form an
extended or extra cargo-space adapted to contain a suitable proportion of the grain
(say conveniently 10 per cent. thereof, if the cargo be wheat-in the case of oats
for example a larger proportional space might be required to sink the vessel to her
proper load line), and upon this I place the hatchways which may be constructed
to contain the usual shrinkage provision of 2 per cent. This extended or extra
cargo-space I prefer to form by carrying the side walls above what would usually
be the deck level, and in cross section I prefer that it should extend to more or
less about one-third of the total breadth of the vessel, the height of it being such

page_text: as is necessary to contain the desired quantity of the grain. It will be understood
that the precise quantity of grain contained in this extra space may vary but it is
important that the quantity should bear such relation to the total quantity of the
cargo as will cause the total shifting of the grain to be confined to this particular
space, the breadth and height of the extra space being so arranged that no ordinary
heeling over of the vessel would enable a line representing the then top or surface of
the grain to clear what I may call the connecting point between the deck and the
wall of the extra space, the result of such an arrangement being that while the
grain in this relatively small or narrow space may shift with the movement of
the vessel, the bulk of the cargo below does not shift and consequently the stability
of the vessel is not appreciably interfered with.
Regarding the hatchways to contain the usual 2 per cent. for shrinkage it should
be understood that these may or may not extend to a less distance across the vessel
than the previously referred to extra space, but for convenience and some
advantages in the working of the vessel it is preferred to make the breadth of the
hatchways materially less than that of the extra space, partly for convenience in
passing along beside the hatchways, partly to prevent the seas from striking the
hatchway combings with the same force and effect that they might do if these were
extended to the outside of the extra space; but it will be understood that, taking
the extra space and the hatchways as containing between them the necessary
proportion of the total cargo, the effect, so far as the non-shifting of the grain and
the provision against shrinkage are concerned, could be attained by carrying up the
walls of the extra space so as to form the hatchways.
Although, as above stated, this construction may be applied to vessels of ordinary
form, I nevertheless prefer the form described in the above referred to Specification
No. 16516 of 1891, particularly on account of the rounded gunwale therein
described, as with that form the grain readily fills up the main portion of the hull
without leaving empty corners which might occur with a sharp angle unless special
means were provided either to fill up those corners or to prevent shifting of the
cargo there by the provision of shifting boards which I prefer to dispense with
altogether.
It will be understood that if desired any ordinary arrangement of the shifting
boards or longitudinal bulkheads may be employed but that they are not essential
and I prefer to dispense with them; the usual thwartship bulkheads may however
with advantage be employed.
The accompanying drawings which represent in Figure 1 a cross section of a
vessel constructed in the form I prefer and Figure 2 a cross section of the upper
part of a vessel of ordinary construction with a sharp angle at the junction of the
side walls and the deck will serve to make the invention clear.
Like letters represent like parts throughout the drawings.
As already explained the hull generally may be of any ordinary construction
but I prefer to form a large curve A at the gunwale or junction of the side walls
with the horizontal portion B which in an ordinary vessel would be the deck and to
carry the portion B with a reverse curve at C so as to form the extra space D as
clearly shown in both figures of the drawings. This space as above described is
intended to contain a suitable quantity of the grain say about 10 per cent. while the
further 2 per cent. required to make good the settling of the cargo would be
contained in the hatchway E which, as shown in the drawings, is preferably,
though not necessarily, of less breadth than the space D. The dotted line F
indicates the position of the vessel when heeling over to an extent of 25°, the
line G perpendicular to F representing the then theoretical position or surface level
of the upper portion of the grain. In practice however I find that even when the
vessel heels over as much as 40° the grain does not leave the wings, and the bulk
of the grain does not shift at all, the stability of the vessel being maintained even
up to 90°. This surface level it will be seen is contained entirely in the space D
as it does not pass the point H at the centre of the curve B C and consequently
does not extend to the curve or corner A. The whole of the movement of the

page_text: cargo therefore with any heeling over of the vessel not exceeding 25° is entirely
confined to the space D so that no means need be provided to prevent the shifting
of the bulk of the cargo the stability of the vessel notwithstanding being fully
maintained. Beyond 25° the stability of the vessel would, in the case of a vessel
of this construction, be sufficient to bring her back to within the 25° so that the
grain would then re-adjust itself if by such unusual heeling over the cargo,
anywhere below the space D, had moved.
The line I is a complement of the line G and indicates the level of the grain in
case of the vessel heeling over to the extent of 25° to the opposite side.
In the case of Figure 2 the arrangements and operation are substantially the
same as in Figure 1, but owing to the sharp corners A which are difficult to fill,
means should be taken to prevent the shifting of the grain at those points. This
may be accomplished by means of shifting boards placed in those parts or by the
provision of small hatches above the corners A through which those corners may
be filled up.
Where suitable means are at hand to force the grain into those
corners no special means would be necessary to prevent the grain shifting there.
Figure 2 is designed to indicate a vessel of ordinary construction altered to carry
out my present invention rather than a vessel specially constructed for the purpose,
the design shown in Figure 1 being the one which, under the latter circumstance, I
should employ.
It will be understood that the hatchway E extends substantially throughout the
whole length of the cargo-space though it may be divided into separate hatches if
desired or the special construction of the vessel necessitate it; the vessel may as
already explained be divided up with the usual thwartships bulkheads.
From a study of the foregoing Specification and drawings it will be seen that I
have designed a vessel absolutely safe under all ordinary circumstances, and yet
capable of carrying a grain cargo in bulk without the provision of any shifting
boards notwithstanding that these may be employed if desired.
Having now particularly described and ascertained the nature of the said inven-
tion and in what manner the same is to be performed, I declare that what I
claim is ;-
1. A bulk-cargo carrying vessel having an extra space such as D adapted to
contain a portion of the grain the level of which in the said space may shift
without endangering the stability of the vessel and so proportioned to the rest of
the hull that no shifting of the grain out of said space can occur with the heeling
of the vessel up to 25° or such other extent as the vessel may be designed to sustain
without danger by the shifting of the cargo substantially as described and illustrated
in the accompanying drawings.
2. In a bulk-cargo carrying vessel the combination with a space such as D of a
hatchway such as E communicating with it and adapted to contain the necessary
amount of grain to make up for the skrinkage due to the settling of the cargo when
at sea so that the space D will always be full when the vessel is on an even keel
substantially as described and illustrated in the accompanying drawings.
3. In a bulk-cargo carrying vessel the combination with a space such as D of a
rounded gunwale such as A Figure 1 for the purpose of avoiding corners so that
the whole of the hull below the space D can be completely filled with the grain
substantially as described and illustrated in the accompanying drawings.
Dated this 28th day of June 1893.
CHAS. D. DOXFORD,
W. P. Thompson & Boult,
Agents for the Applicant.