120

THE COLLIERY GUARDIAN

January 18, 1918.

steel discs and rods, whilst, instead of the buckets
being attached to a chain, plates connected by hinge
pins are adopted.

The equipment for mechanical bunkering so far
referred to may be described as of a comparatively
simple description which may be adapted to meet the
requirements of tonnage to be handled by adding to
the number. If the bunkering trade of a port is
frequent, regular and extensive, and comparatively
smooth water conditions are obtainable in a protected
harbour, then more extensive or elaborate floating
plant can be considered. One type of bunkering
barge, which is provided with self-trimming holds, has
an equipment comprising trolley tubs and hoist
towers; the equipment being somewhat similar to
that adapted to a self-discharging collier which was
described in the previous issue of this series. In the
case of bunkering, the hoisting frames are, however,

i ■

• 'Ail/

Fig. 2.—Bunkering a Great Ocean Liner with Portable Elevators.

considerably higher and in the form of a tower, to
allow of delivery at a greater elevation. The illustra-
tion of fig 3 will serve to show the arrangement of
this barge, which is equipped with three hoist towers
each provided with two chutes. The height of
delivery can be varied to suit the conditions, as the
hopper into which the trolley tubs are tipped can
be raised or lowered, and the chutes attached are
telescopic and adjustable. We may next consider
barges and pontoons equipped with elevators.

Elevator Barges.

One interesting type of elevator barge is of steel
construction and 154 ft. long, with a beam of 27 ft.
and a depth of 11 ft. 6 in. The coal bunkers are
divided longitudinally by two bulkheads, to provide
a central passage way 4 ft. 6 in. wide and 20 ft. deep,
in which operate two inclined elevators. These
elevators are each supported by a trunnion in bearings
on a wheel frame, capable of movement along rails
extending one on each side of the top of the passage
way. The elevator buckets are 3 ft. in width, and are
spaced 18 in. apart to allow for large coal. The bunker
on each side of the elevator passage is divided into
nine pockets, all having double-hinged doors for the
discharge of the coal into the elevators, and the bun-
kers have self-trimming floors. The elevator is driven
at a speed of 65 ft. per minute by a double-cylinder
horizontal steam engine compactly arranged at the
head, steam being supplied through flexible tube
from the boiler, situated aft; and the coal is
delivered into the side bunkers of a vessel by an
adjustable chute. The elevators can be moved along
the barge by means of chains extending along the top
of the passage-way and driven by a winch at one
end. The barge is self-propelled, at a speed of about
five knots per hour, by twin screws, operated by a
compound, vertical, condensing engine, steam being
provided by a vertical boiler. A warping capstan
is included in the equipment. Special features of
this plant are: the arrangement whereby the coal
dust nuisance is reduced, steam from the elevator
engine being exhausted into the coal before discharge
into the chute; and the driving gear of the elevators
is of special construction whereby an intermittent
or jerking motion is obtained. Each elevator can be
operated independently of the other, and the average
rate of working is 100 tons per hour—200 tons in
all. The weighing of the coal is allowed for, and the
capacity of the barge is 450 tons. In the case of
bunkering through deck hatches an adjustable
conveyor is provided to take the place of the chute.
This conveyor is supported on a carriage, can be
moved along the rail track of the elevators, and is
capable of being revolved or varied in inclination.

Another floating elevator equipment for bunkering,
which is independent of the coal to be handled, may
now be described. The plant is supported on two
pontoons and serves to discharge barges lying
between. The pontoons are 8 ft. wide and 60 ft. in
length and afford a space of 25 ft. between for a barge.
They are connected together at the base and carry
an arched plated-girder structure which supports the
main deck, the elevator framework extending there-
from. The elevator is capable of adjustment verti-
cally so that the buckets can be lowered on to the top
of the coal in the barge as it is withdrawn; and the
elevator can also be swung from the centre on either
side for automatically trimming the coal in the barge,
the latter being moved along as its cargo is with-
drawn. The elevator discharges into a hopper at the
top of the structure, from which the coal is delivered
on to two inclined conveyors serving two horizontal
adjustable boom conveyors, which are situated at

different elevations and are capable of delivering—
when fully extended—at a distance of about 50ft. from
the side of the pontoons, thus serving for delivery into
a further deck hatch of a vessel and at an elevation
of 50 ft. above water level. For deliveries into side
ports, four extendable horizontal conveyors—having
adjustable chutes—are supported at the main deck
level of the pontoons, and these conveyors are fed by
chutes from the hopper referred to. The whole equip-
ment is electrically operated, the steam boiler and
electrical generating plant being situated on the top
of one of the pontoons; and the elevator, as well as
each conveyor, is independently operated by electric
motors. A buffer boom, permits of the pontoon lying
25 ft. from the side of the vessel whilst bunkering and
thus allows of cargo barges working between. This
equipment is designed to deliver 300 tons per hour
and is self-propelled, electrically, by double screws.





This equipment differs in general principles from
that previously described, not only because it is inde-
pendent and serves to discharge coal barges, but the
elevator has also a self-digging action somewhat
similar to the portable elevators referred to, whereas
the elevator barge not only carries the coal to be
delivered but the elevator is fed from discharge doors
of its hold. In both cases it will be noted that,
conveyors are utilised for delivery in addition to
chutes; to obtain a greater range of distance than can
be obtained by gravity discharge through chutes
without great elevation of the elevator structure.
Another form of independent elevator equipment for
discharging barges alongside and bunkering, com-
prises a gantry structure supported on a pontoon.
This structure carries a continuous chain of buckets
in a double-hinged frame, which extends over the side
of the pontoon and is adjustable in elevation, whilst the
extension of the frame is suspended over the coal barge
and is capable of a side-trimming motion. The coal
is discharged from the elevator buckets into a hopper
on the pontoon, and then parses by way of an inclined
conveyor extending over the fore part and is deli-
vered, at an elevation, through hopper chutes. The
overhanging weight of the elevator frame and buckets
is counterbalanced, and the hinged frame can be
raised on to the pontoon when not in use. Other designs
of coal bunkering craft which discharge their own
cargo have as their principal feature self-trimming
holds which are automatically discharged on to a
travelling conveyor beneath.

Conveyor Barges.

A self-discharging collier having conveyor equip-
ment was referred to in the previous number of this
series; and barges for bunkering have also been pro-
vided with similar equipment, which it is unnecessary
to describe further except to state that one barge of
this description (one-half of which is shown in fig 4),
has a coal capacity of 725 tons, its length being
172 ft., beam 28 ft., and loaded depth 1.5 ft,, with a
loaded draught of 10 ft. 9 in. The conveyors are
operated electrically by separate motors, the supply
being obtained from the quay side through flexible
cables. This craft has four delivery chutes and a
total of about 160 tons of coal per hour can be handled.

Another type of a coal bunkering barge with con-
veyor equipment is 157 ft. long, 36 ft. in width, and
16 ft. deep. It is propelled by two sets of compound
engines situated aft, and has a coal capacity of 800
tons. The conveyor is of the endless-chain type
carrying steel buckets, and travels in a centra] tunnel,
fore and aft, along the bottom of the craft. Forward
it rises at an angle to a height of 65 ft. above water
level, and is supported bv a gantry, at the top of which
is the discharge drum of the conveyor, where tlje coal
passes into a hopper with adjustable telescopic chutes.
The hopper and chutes are suspended from a revolv-
ing jib. controlled from the deck of the craft and
operated by two steam winches. The conveyor is
driven by one or other of the two sets of propelling
engines. This barge delivers an average of 200 tons
per hour, the supplies being automatically weighed
as the conveyor emerges from the tunnel. In operat-
ing the equipment a man in the tunnel controls the
opening and closing of the hold doors which discharge
on to the conveyor, and deliverv is controlled by a
man on the receiving vessel, who directs the winchmen
to operate the chutes and regulate the supply, and
who signals to both the tunnel man and engine room.

A more elaborate equipment of the conveyor type of
barge which mav be mentioned is designed for a coal
capacity of 1.250 tons and to handle an average of
150 tons per hour. The hold of the barge is divided

into a number of pockets by cross bulkheads; the
floors of these pockets consist of double doors hinged
near the centre, which are raised by hydraulic rams,
from the outside edges, to an angle of 45 degrees;
thus trimming the coal towards the hopper doors
serving the conveyor in the tunnel. The sliding doors
are operated by a shaft extending the length of the
hold, but are independently controlled from the deck
by means of pneumatic clutches. This shaft also
carries a revolving rake or trimmer at each hopper
door, to prevent large lumps of coal blocking the out-
let or overloading the conveyor buckets. The con-
tinuous conveyor chain of buckets extends along the
tunnel, rises vertically at the fore end and returns
horizontally at an elevation, being supported by a
gantry structure. The buckets are automatically,
tipped into two elevated hoppers, each serving two
adjustable chutes. The barge is also provided with
a transporter crane working with a grab, which
enables the hold to be self-filled from barges alongside.
The grab track of the transporter extends beneath the
conveyor gantry and at right angles to it, the part
extending over the side of the barge being hinged so
that it can be raised when not in use.

From the descriptions given it will be evident that
considerable attention has been given to bunkering
craft equipped with elevators and conveyors, and that
several types are available differing in details of
construction, and in some cases in general design.

Floating Cranes and Transporters.

Floating cranes form a simple and comparatively
inexpensive type of plant which can be adapted to
bunkering as well as discharging. Both the arrange-
ment of such equipment and the design of the crane
call for special consideration in view of the radius
of action and the height of lift above the level of
the deck of the barge or pontoon. In addition, the
form of the jib must allow a maximum clearance if
it is to be arranged for slewing over the deck of a
steamer; and the jib is provided with a derricking
or luffing motion to vary the radius of handling as
well as to hoist it out of the way when not in use.
Cranes can be adapted for movement along the deck
of a barge, if the radius is not sufficent to command
the length of the hold on either side to discharge the
coal therefrom; also, it can be used for discharging
other barges alongside, and it can be arranged either
for delivery by way of the deck hatch of a vessel or

Fig. 3.—Hoisting Tower—with Two Adjustable
Chutes—of Specially-Equipped
Bunkering Craft.

for side-port bunkering. In the latter case a port-
able hopper can be slung over the port, or an elevated
hopper can be provided, on the barge, for delivery by
means of chutes, and the elevated hopper can also
be movable on the deck of the barge if necessary. In
the case of a crane supported on a pontoon, which
does not carry the coal to be handled, but only serves
for bunkering from other barges alongside, or for dis-
charging colliers into barges, the conditions are
similar to those of a barge crane. It will thus be
appreciated that floating cranes can be adapted to
various conditions of bunkering.

As regards floating transporters, alternative condi-
tions may also be considered. For example, the
transporter tracks may be extended over both sides
of the pontoon or barge, or over one side only; in
either design the tracks are hinged to allow of being
hoisted when not in use. As in the case of floating