IMPROVEMENTS IN AND RELATING TO WATER BALLAST TANKS OF SEA-GOING VESSELS to be as follows
Year: 1885

page_text: I JAMES NELSON of 20, Wentworth Place, Newcastle-upon-Tyne, Engineer do
hereby declare the nature of my invention for "IMPROVEMENTS IN AND RELATING
TO WATER BALLAST TANKS OF SEA-GOING VESSELS to be as follows:-
"
My invention has reference to water ballast tanks of sea-going vessels, that is to
say, to tanks situated in or below the hold of vessels and which when the ship is
to be in ballast are filled with water and which at other times are either filled with
cargo or left empty. With some cargoes it is objectionable to have these tanks
empty, while to enable cargo to be stowed in them it has been found laborious to
remove the tank tops.
Now my invention consists in constructing and fitting the tops of water ballast
tanks so that they can be lowered bodily in one or more pieces to the bottom of
the tank or nearly so and again raised to the top of the tank according as the tank
space is required for cargo or for water ballast.
My invention also comprises means or apparatus for raising the tank tops and
means of forming a water tight joint at the top of the tanks when the tops are
raised.
The means or apparatus whereby I raise the tank tops consists of hydraulic rams
placed in any suitable positions, say for example, in the keelson and at the sides.
and ends of the tanks; these rams may be worked by a special donkey engine or
by any of the ordinary engines of the vessel and are connected to the tank tops by.
strong bars or other suitable connections so that as the rams rise the tank tops are
lifted. The "ceiling" which is usually placed upon the tank tops moves up or
down with them. When the tank tops have been raised, or while they are being
raised, I allow the external water to flow in to fill the tanks. When it is required.
to lower the tank tops, the water is pumped out and the tops with the ceiling and
hydraulic rams descend by gravity. Instead of hydraulic rams I can employ other
means of raising the tank tops such for example as sheaves or blocks and tackle or
screws.
In order to form a water-tight joint at the top of the tanks, when the tops are
raised 1 fix around the tops a bar or beam to the upper face of which I secure an

page_text: india rubber or other packing which projects from the bar or beam; corresponding
inturned flanges exist along the top edges of the tank so that when the tank top
has been raised, the packing is forced against these flanges or the packing may be
on the flanges instead of on the bar or beam. Additional or other means may be
employed to ensure a good joint such for example as clamps, scrows or other like
devices.
In order to prevent the tank tops being forced up too far or to "stay" them
I attach chains or other folding or collapsible connections to the under side of the
tops and to the floor or other part of the vessel, these chains or connections being
taut when the tops are fully raised and the pressure of the water is upon them.
Dated him
Manal 100r
Dea-going vessels.
I JAMES NELSON of 20 Wentworth Place, Newcastle-upon-Tyne, Engineer 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:-
My invention has reference to water ballast tanks of sea-going vessels, that is to
say to tanks situated in or below the hold of vessels and which when the ship is
to be in ballast are filled with water and which at other times are either filled
with cargo or left empty. With some cargoes it is objectionable to have these
tanks empty as it may make the vessel top heavy while to enable cargo to be
stowed in them it has been found laborious to remove the tank tops.
Now my invention consists in constructing and fitting the tops of water ballast
tanks so that they can be lowered bodily or in one or more pieces to the bottom
of the tank or nearly so and again raised to the upper part of the tank according
as the tank space is required for cargo or for water ballast.
Various means or apparatus may be employed for the purpose of raising the
tank tops.
Hydraulic apparatus placed in any suitable positions will; answer the
purpose; these rams may be worked by a special donkey engine or by any of
the ordinary engines of the vessel and be connected to the tank tops by strong
bars or other suitable connections so that as the rams rise the tank tops are lifted.
The ceiling" which is usually placed upon the tank tops moves up or down with
them. When the tank tops have been raised or while they are being raised by the
hydraulic apparatus the external water is allowed to flow in or is pumped in to

page_text: fill the tanks. When it is required to lower the tank tops, the water is pumped
out and the tops with the ceiling and hydraulic rams descend by gravity. Instead
of hydraulic apparatus I can employ other means of raising the tank tops, such for
example as sheaves, or blocks and tackle, or screws.
I prefer however to dispense with all mechanical or other lifting arrangements
and to depend entirely upon the lifting power of the water itself for raising the
tank tops, that is to say, that the water is caused to enter the tanks at the bottom,
and the tops then gradually rise by buoyancy, or float, until they attain their
highest position.
In order to form a water-tight joint at the upper part of the tanks when the
tops are raised I fix around these tops a bar or beam to the upper face of which
I secure an india rubber or other packing which projects from the bar or beam ;
corresponding inturned flanges oxist along the upper edges of the tank so that
when the tank top has been raised the packing is forced against these flanges;
or the packing may be on the flanges instead of on the bar or beam. Additional
or other means may be employed to ensure a good joint, such for example, as
clamps, screws or other like devices.
In order to prevent the tank tops being forced up too far or to "stay" them
I attach chains or other folding or collapsible connections to the under side of the
tops and to the floor or other part of the vessel, these chains or connections being
taut when the tops are fully raised and the pressure of the water is upon them.
"
The accompanying drawings will serve to illustrate my invention:-Figure 1 is
a transverse section of a vessel having a water ballast tank in the hold, this view
showing the tank top in its raised position. Figure 2 is a similar view with the
tank top lowered. a is the skin of the vessel forming the bottom and sides of the
water ballast tank as usual, the ends of the tank are formed by transverse partitions
or bulkheads at any suitable positions. c, c is the tank top and d, d the "ceiling'
placed thereon; e, e are chains connecting the under side of the top c to the skin a
for the purpose hereinbefore stated; instead of these chains other suitable con-
nections may be employed. f is an angle iron bar fixed around the top c, and g
is india rubber or other packing secured to this bar, h is a stringer or plate con-
stituting an inturned flange along the upper edge of the tank; the bar f, stringer h,
and packing g make a water-tight joint at the upper part of the tank when the
top c is in its raised position. In order however the better to ensure a good joint
I think it desirable to adopt further means consisting of a series of vertical tapered
bolts or pins i, i fixed to the bar f; these bolts as the top o rises enter corresponding
holes in the stringer h, and cotters k, kare then driven into slots in the bolts the
parts being thus drawn tightly together.
In order to prevent contact of the cargo with the ends and sides of the tank
when such cargo is placed in the tank above the lowered top c I hinge to the said
top c flaps l, which in the lowered position of the top are placed vertically (see
Figure 2) and attached to the stringer h; thus forming close ceiling to the space
between the tank top in its lowered position and the stringer h, while in the raised
position of the top they lie upon it (see Figure 1). Instead of employing these
hinged flaps, loose boards or hatches may be employed.
It will be readily understood that when it is required to raise the tank top c
from the lowered position represented in Figure 2 it is only necessary (after
releasing the flaps 1, 1 from the bar h, to allow water to enter, or to pump water
into, the tank below the top c; the top c will float and as the water level rises
will gradually ascend until its bar f with the packing g comes against the stringer h;
the cotters k, kare then driven into the slots of the bolts i, i to secure the parts
together. On the other hand when it is required to lower the top c from the
raised position represented in Figure 1, the cotters k, k are removed and the water
is then pumped out of the tank; as the water level falls the top c will descend by
5 gravity.
Figure 3 is a transverse section showing tanks in the after hold of the vessel
at the sides of the ordinary tunnel m for the propeller shaft. One tank is shown

page_text: with the top c lowered for cargo and the other with the top raised for water
ballast.
Figure 4 is a similar view to Figure 1 except that there are permanent water
ballast compartiments n, n of any ordinary construction at the sides of the vessel
between which tanks are the convertible tanks with my arrangement of tops;
these permanent water ballast compartments n, n are desirable in vessels intended
to carry very light cargo, such as cotton.
In cases where it is not thought well to depend upon the lifting power of the
water itself to raise the tank tops other means may be employed, such as hydraulic
apparatus, or screws, or blocks and tackle, as already mentioned and in such cases
the tops c may with advantage be made flat throughout instead of being of the
punt-like form shown in the figures.
Having now particularly described and ascertained the nature of my said
Invention, and in what manner the same is to be performed, I declare that what
I claim, in respect of water ballast tanks of sea-going vessels, is
1. Constructing and fitting the tops of such tanks so that they can be lowered
to the bottom of the tank or nearly so and again raised to the upper part of the
tank, substantially as and for the purpose herein beforo described.
2. In combination with tank tops, which can be lowered and raised as referred
to in claim 1, I claim means for making a tight-joint between the tank top and
the upper part of the tank, substantially as herein before described.
3. In combination with tank tops, which can be lowered and raised as referred
to in claim 1, I claim the employment of chains or other connections, as herein-
before described, to act as stays, the upper and lower ends of such chains or
connections being attached respectively to the tank top and to the bottom of the a
vessel.
Dated this ath das of 000