Improvements relating to Doors for Watertight Bulkheads.
Year: 1898

page_text: Date of Application, 28th Apr., 1898-Accepted, 16th July, 1898
COMPLETE SPECIFICATION.
Improvements relating to Doors for Watertight Bulkheads.
I, PERCY LEWIS ISAAC, of Winchester House, Old Broad Street, in the City of
London, Marine Engineer and Naval Architect, M.I.N.A., 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 relates more particularly to watertight doors for watertight coal
bunker bulkheads, especially those longitudinal bunker bulkheads which are
generally placed on each side of the boiler and engine compartments in steam
vessels and is designed to provide for insuring more effectually than heretofore
that such doors when open shall always be capable of being closed notwithstand-
ing the coals that may be lying through the doorways, or other obstacles or any
accumulation of dust or dirt in the grooves, within which the doors slide.
The doors of bunker bulkheads as heretofore constructed require to be moved
downwards to close them (except my watertight door, Patent No. 5543, 21st April
1886). Moreover these doors are seldom made watertight and therefore the longi-
tudinal bunker bulkheads are of little use in cutting off the flow of water coming
through an aperture in the side of the vessel occasioned by a collision, to the
most vital parts of a steam vessel.
The ordinary down-closing bunker doors are likewise, in an emergency, pre-
vented from being properly closed by their having to be pressed down on to
coal, which is lying through the door-way for use by the stokers; and in addition
to this, any accumulation of dust and dirt tends to jam the door in its descent and
thus prevent it from being effectually closed.
In my vertical up-closing bulkhead door (Patent A.D. 1886 No. 5543) the
height of the door prevents the sill of the doorway in many instances from being
on a level with the stokehold platform, and therefore the sill has to be more or
less raised above the platform, as the depth below the platform is not always
sufficient to admit of the door sliding far enough down. This raising of the top
of the door (which top forms the sill) presents a difficulty in the working of the
coals by the stokers.
I overcome these difficulties by making the bunker bulkhead doors either to
swing upwards or downwards (instead of a vertical downward movement as hereto-
fore) within a double frame which is open on three of its sides. The door there-
fore in the act of closing passes through the coal and throws it aside, as well as
clearing the slide in which it works, of any accumulation of dirt. If this door
is made to close upwards it turns or swings on one of its lower corners, and there-
fore when it is open the door lies on its edge below the stokehold platform thereby
having depth for the width of the door, when there might not be sufficient depth
if the beight of the door had to be provided for. By hinging the door on one of
the top corners and by letting it close by a downward movement, it has the
additional advantage of its own weight in assisting the closing.
My apparatus is conveniently and advantageously constructed as follows, that
is to say, the door proper consists of a cast steel or other metal plate, on one
corner of which is cast a wormed quadrant, into which works a worm, by which

page_text: means the door is raised or lowered; one edge of the door is made with a V edge
so that it can cleave or break through any lump of coal. The outside faces of
the door are likewise wedge-shaped so that they can be drawn close and water-
tight within the slides. The said door works between a double cast steel frame,
three of its sides being made open to enable the door to pass through.
Instead of the worm and the worm quadrant which is worker from the upper
deck and also in the stokehold by a wheel and gearing or with a ratchet wheel
and brace, the door may be raised or lowered by having a lever affixed on one
corner of the door, at the end of the lever there is a movable nut, through which
a screw rod works for raising or lowering the door from the deck.
If this door is reversed, that is to say, if it he hung on one of its top corners,
and actuated as described above, it will have the additional advantage
of having: (1) Its own weight in assisting its being more rapidly closed. (2)
In not having to fall at all below the stokehold platform and (3) that the coals
will not be worked over the V edge which thus will not be liable to wear.
In the accompanying drawings, I have shown how my said invention may be
conveniently and advantageously carried into practice.
Figure 1. Sheet 1, is a front elevation of my apparatus, wherein the door is
provided with means for opening and closing it by hand.
Figure 2, Sheet 2, is end view on the line C D Figure 1.
Figure 3, Sheet 2, is an end view on the line A B Figure 1.
Like letters indicate corresponding parts throughout the drawing (a) is the door
which consists of a cast steel plate and which is fitted to swing radially between
cast steel frames (a¹) & (b) on the bolt (7) this bolt has a square (u) on it to
keep it from turning in the frame (a¹) and (g) is a metal bush fitted in the door
for it to turn easy on the bolt (p).
The frames (a¹) are bolted to bulkhead (e) by flush headed bolts (r) and the
frames (6) are bolted to frames (a) and bulkhead (c) by bolts (n) and (o) leaving
a space (v) for the door (a) to slide in and with sufficient space so that when the
door is closed, the space (61) becomes water-tight.
The door (a) has a knife wedge-shaped edge (w) on its lower edge for cutting
or cleaving through any obstacle such as coal that may get in the opening (61)
or between the frames (a¹) & (b) when the door is being closed.
This door is closed by means of a toothed quadrant cast on door (a) at (d) in
which works a phosphor bronze worm (f) this worm is keyed on to the rod (g)
which is carried in brackets (m) having metal bushes (s) and are bolted on the
bulkhead (c).
The door is closed or opened by turning wheels (h) at the top, or wheel (2) at
the bottom.
The wheel (2) at bottom is fixed on the bracket (t) which allows for the mitre
wheels (1) and (2) to work the rod (g).
The rod (g) can be carried to the upper deck and the door can be closed or
opened very quickly by turning the wheel (h) which actuates worm (f) in toothed
quadrant (d) cast on door (a) or it can be closed or opened as required by the
stoker in the stokehold by turning the wheel (ż).
(x) is a lubricator for keeping the bolt oiled for the door to turn easily on.
Having now particularly described and ascertained the nature of my said inven
tion, and in what manner the same is to be performed, I declare that what I
claim is:-
First. A watertight door that can be fitted to the ordinary watertight bulk- 5
heads within a vessel, but more particularly for fitting to the bunker bulkheads
which as heretofore constructed are seldom if ever made watertight.
Second. If these bunker bulkheads were so constructed and fitted with the
door, they would be of great additional security to the vessel.
Third. To obtain an efficient watertight door to meet the aforesaid requirements, 5

page_text: the door herein specified is so constructed and arranged that the closing
effected by moving it radially downward.
Fourth. That by having one edge of the door wedge, or knife edge shaped, it
affords the means of cutting or cleaving through coal that is always lying within
the doorways for constant use by the stokers.
Fifth. By actuating this swing or radial door from the upper deck through a
powerfully geared arrangement, means are afforded for moving the door to and fro,
so that each time the door with its knife edge may give a cutting blow to the
obstacle within the doorway.
Sixth. Each cutting blow enables the door to close gradually more & more &
whatever gain is obtained goes to cutting off the flow of water through the door-