IMPROVEMENTS IN ACCOMMODATION LADDERS FOR SHIPS AND OTHER VESSELS AND ALSO FOR TIDAL LANDING STAGES to be as follows
Year: 1884

page_text: JOHN MCCALLUM of West View Terrace Lemington on Tyne in the County
of Northumberland Joiner do hereby declare the nature of my Invention for
"IMPROVEMENTS IN ACCOMMODATION LADDERS FOR SHIPS AND OTHER VESSELS
AND ALSO FOR TIDAL LANDING STAGES to be as follows:-
"
The improvements have for their object the enabling of persons to go easily on
them at different angles, the steps always being level at whatever elevation or
depression. The hoisting or lowering of the lower end of the ladder causes the
steps to move horizontally. The ladder is constructed with the usual top platform
to the underside of which is fixed two teeth quadrants. On inside of ladder sides
are ratches (one for each quadrant to suit teeth of quadrant) with sliding bar
attached to each ratch and extending down the inside of ladder sides in a groove
with holes at intervals in which is inserted the back pin of frame under steps.
There is a grooved or slotted plate covering sliding bar through which the back
and front pins of step frame traverse, the plate being curved outwards, for front pin
of step. This ladder is also applicable for Tidal Landing Stages by putting wheels
at lower end of ladder, the rising and falling of the tide acting on the ladder the
same as hoisting or lowering..
...
1

page_text: I JOHN MCCALLUM, of West View Terrace, Lemington on Tyne, County of
Northumberland Joiner, do bereby declare the nature of my Invention for
IMPROVEMENTS IN ACCOMMODATION LADDERS FOR SHIPS AND OTHER VESSELS AND
ALSO FOR TIDAL LANDING STAGES and in what manner the same is to be performed,
to be particularly described and ascertained in and by the following statement:-
The improvements have for their object the enabling of persons to go easily up
or down at the different angles the ladder may be placed, and to suit the different
heights by hoisting or lowering the lower end of ladder; the steps always remaining
level. The ladder is constructed with top-platform, to the underside of which is
fixed two teeth quadrants. On inside of ladder sides are ratches, one for each 1
quadrant to suit teeth of quadrant with sliding bar attached to each ratch and
extending down the inside of ladder in a groove with holes at intervals in which
is inserted the back pin of frame under steps. There is a grooved or slotted plate
covering sliding bar, through which the back and front pins of step frames
traverse, the plate. being curved outwards for front pin of steps.
1 Quadrant, ratch and sliding bar.
2 Grooved plate curved for front pin of step.
3 The complete movement effected by numbers one and two.
The advantages of this ladder over that now in use are various; in that now in
use the steps being fixed into the sides of the ladder, can only be level at one 2
angle of the ladder. In vessels where part cargo is discharged off the ports of
call, the ship becomes lighter, and it is then necessary to lower the lower end of
the ladder to accommodate boats coming or going with passengers or others to the
ship. With the ladder now in use; when it is lowered the outer edge of the steps
becomes more and more depressed until it becomes dangerous to move on them
by any persons except seamen. Also when taking in cargo the vessel becomes
heavier and consequently lower in the water, therefore requires to be hoisted for
the convenience of boats coming alongside, the hoisting of the ladder causing the
front edge of the step to be elevated so that instead of placing the foot on the step
it has to be on the edge of the step.
The improved accommodation ladder obviates all this unpleasant feeling and
danger of movement as the steps are always level and solid at whatever angle the
ladder may be placed from vertical to horizontal. The movement of the steps is
caused (see Drawing) by two teethed quadrants being fixed to the underside of the
usual top platform above each side of the ladder sides. The ladder is fixed to the
platform in the usual way with a bolt through eyes under platform and top of
sides,
On the inside of ladder sides are ratches, one on each side to suit teeth of
quadrants and gearing together with sliding bars one on each side attached to
ratch and extending down in a groove in each side of the inside of ladder sides,
At regular distances asunder are holes in which are inserted the back pins or studs
of metal frames under wooden step. The frames under steps are made with two
back and two front pins on the ends, the back pins are secured into the holes in
sliding bar.
The sliding bars are covered with a plate extending outwards to front of ladder 4
in which is a straight groove at back for back pins of step to move in; the groove
extending forward to front in a curve through which front pins of steps traverse.
The sides of the ladder are secured by means of tie bolts. The action of the
steps is automatic, any hoisting or lowering of the lower end of the ladder causes
the quadrant acting on the ratchet plate to raise or depress the sliding bar to b
1

page_text: which the back pins of step are attached. The steps follow the movement working
in the grooved plates and are thus kept constantly level at whatever angle the
ladder is placed in from vertical to horizontal. For vessels lying in dock it could
be used as a convenient gangway for passengers by having two additional eyes
secured to the side of top platform, the ladder could then be turned round and
secured at right angles with the ship and two wheels placed at lower end of the
ladder and resting on the quay or wharf, the rising or falling tide causing the ladder
to move outwards or inwards on the wheels and acting on the ladder same as hoisting
or lowering. To adapt this ladder for tidal wharves or landing stages it is only.
necessary to fit a narrow platform at the top to carry the gear (same as above)
with wheels at bottom to allow of it moving freely on the platform of floating stage
or wharf.
What I claim as improvements over the ladder now in use are.
First The tooth quadrants and ratchet with sliding bars.
Second. The grooved plates covering sliding bars and curved outwards for pins
of steps.
Third. The movement of the steps caused by the combined action of quadrant,
ratchet, sliding bars and grooved plates.