Schneider-Canet 240mm L/45 QF gun
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I. Features The 240mm L/45
Schneider quick-firing coast gun was expecially designed as armament of upper
batteries. Its distinctive feature is that it can be operated entirely by
hands. Undoubtedly, at the present time war
materials has seen an increasing employ of motive power, and also the firm
Schneider & C. did not dropp back in this field. Nevertheless there is no
denying that in the defence of the coasts there are a lot of particular
instances where the installation of heavy weapons which required only the
arms of its crew to operate is very profitable. Moreover, considering that
this 240mm Schneider gun is a quick-firing piece, able to attain and sustain
a rate of fire of 3 – 4 rounds a minute with trained gunners, no wonder that
it had interested greatly the technical press, urging several governments to
command it. The models put in service differ only in minor manufacturing
details, that change neither their main features, nor their overall
operation. As such, the following brief descrption is in principle
appropriate, and suffices to give a complete idea of the gun. II. Description 1st Gun-body. – The gun-body, in
hardened annealing steel, is made along the ordinary manufacturing system of
the firm Schneider & C. It is composed by a thick tube which runs the
whole length of the gun, and is
strenghtened by a double hooping. The hooping of the first row included a set
of short hoops between two long jackets : the B tube (rear jacket) is used to
reinforce the opposition to the déculassement with its mass; the A tube
concurs to ensure the hardness of the gun-body. The hooping of the second row
is composed by a rear jacket and a set of short hoops. The breech mechanism is of the interrupted
screw type with pad obturator system De Bange. Its mechanism, operating by
means of pinions and gears, enabled an extremely rapid manipulation. The
repeat firing device could be used with electric and percussion tube, and is
equipped with mechanical safety arrangements against premature fires and
prolonged fires. A blowing
device, by means of the high pressure of the air, is able to dispel the gas remained
in the bore after the departure of the shell. This device is connected with
the operation of the breech, and works automatically at the beginning of the
opening movement of the breech itself. Thence it assures a total safety
against back-flash. 2nd Carriage. – The carriage is
composed by the cradle, the slide, the bedding, the sighting and aiming
gears, the service platform, the loading gear, the supplying mechanism, and
the mask. a) The cradle carrying the gun is made of
cast steel, with bronze friction packing. It carries two hydraulic buffers
with central controlling ram, and a compressed air run-out gear, with
hydraulic joints. The buffers minimize and controll the gun recoil; during
the recoil, the air of the run-out gear is subjected to a compression that
leads the return to the run-up position. This movement is controlled by the
work of the throttling bar of the piston rod, that operates to plug the
hydraulic shock. The cradle
carries also : two trunnions; the firing gear, whom controlling mechanism
(pistol grip) is placed near the aimer; the toothed arc, made in forged
steel, and utilized to point in elevation; the sighting apparatus. b) The slide carrying the gun-cradle
structure is made in cast steel. It is composed by two trail cheeks joined to
a round plate. The trail cheeks carry the trunnions of the cradle with the
interposition of horizontal rollers. The plate form the upper roller path of
the traversing movement, and has the support of the pivot. The slide
carries : two hooks, placed one forward, the other behind, in order to
counter the rising up; the controlling mechanism of pointage, whom gears are
lodged in bronze protective boxes; the joints of the mask; the joints of the
service platfom. c) The bedding carrying the slide is made in
cast steel, and has the shape of a round plate. It is bolt on the battery
terreplein by means of 24 bolts, that loan on a collar of the bedding. The
slide rests on horizontal rollers, placed on a roller plate arranged on the
bedding, and embraces also a vertical pivot coming from the foundry with the
bedding, and furnished with a bronze friction ring. The bedding carries also
the traversing toothed wheel. d) The sighting gears. – The elevating
apparatus is composed by a set of gears, controlled by a handwheel placed
near the aimer, on the left side of the carriage, and activating a pinion
geared with the toothed sector attached to the slide. The gun, thanks to it,
can take in the firing angle corresponding to the distance from the target.
An anti-friction mechanism inserted into the system prevents the trasmission
of every kind of stress able to damage the gears. The connections between the
gears were fixed in order to minimize the force required to point in
elevation; to constantly lubrificate the rubbing parts greasing devices are
provided; and the apparatus is irreversible since it has a worm wheel
connected with an endless screw. This apparatus
complemented by a quick motion
gear, that allowed to lower quickly the gun in loading position, at a – 5° The traversing apparatus is composed by a
set of gears, controlled by a handwheel placed near the aimer on the right
side of the carriage, and activating a pinion geared with the toothed sector
of the bedding. All the arrangements introduced to assure the easy
manipulation and the irreversibility of
the gears of the elevating apparatus are utilized also for the traversing
apparatus. The sighting
gears is fundamentally an arc sight, where is assembled a dial sight with
reticle. The graduations are in millièmes of the range. f) The service platform, firmly bolted on the
joints of the slide, is composed by a metal framework; its frame comprised
two strong longitudinal beams assembled by braces. Through rollers mounted on
springs it is put on a roller plate concentric to the pivot of the carriage.
Floorings with duckboards in strong wood are placed on the right side, on the
left side and behind the platforom, for the gunners and the loading gear. The
supplying mechanism is placed on the left side, behind the flooring of the
aimer. Finally the apparatus has also access ladders and a balustrade. g) The loading apparatus is composed by a
conveyor and a thrower. It was
operated entirely by hands : it takes the projectile from the supplying
place, carries it along the axle and in parallel with the axle of the gun,
beforehand placed at a – 5° The conveyor is composed by a metal
framework made by two vertical blades interlaced, and able to turn around a
horizontal axle. Their supports are fixed at the service platform. The joints
of the thrower frame are placed on the upper part of the conveyor. It is
controlled through a handle lever, which allows to turn the rotation axle. A
spring connected on the one hand with a fixed part of the loading mechanism,
and on the other hand with the conveyor, serves to slow down the movement of
the conveyor when it carries the projectiles along the axis, and to speed up
it when it goes to take the projectile at the suppling place. The loader is composed by a frame joined
at the conveyor and a revolving spoon. The frame makes the roller path of the
spoon. It carries a rod that engages automatically the loading apparatus with
the gun or the supplying place : it can be disengaged only by hands. The revolving spoon receives the
projectile held by a stop bolt assembled between the belts; it is mounted on
joints and provided with an automatic lubrificator to make easier the
movement. A lever controlled by hands connects it with the frame, or unlocks
it. Then an operating handle serves to throw it. It rolls on the inclined
roller plate of the frame until it is stopped by the conical part of the
chamber. At the same time, the stop bolt of the projectile goes down
automatically. The projectile continues its moving by inertia with a
sufficient speed to reach the cone, and stops there. A safety lever
connected with the lever of the spoon and the rod of the frame prevents from
throwing the projectile when the conveyor is not assembled with the gun. h) The supplying mechanism is composed by
some wheelbarrows, a waiting place, a hoist and a supplying place. The wheelbarrow consisted of a wooden
shaft, two wheeles, an axletree, two lateral joints, and an iron platform
covered with brass. The projectiles, got at the store, are placed on this
platform, and are carried in this way to the waiting place. This mean of
transport is rustic and dispenses with the installation of rails on the
terreplein of the battery. It can work even in the even of a damage of the
terreplein itself. The arrangements of the wheelbarrows were designed in
order to make easy and rapid the loading and the unloading of the
projectiles. The waiting place, situated near the
hoist, is invariably connected to it. It is a sort of box where the
wheelbarrow can be bound, staying guided by its lateral joints, without being
trained by the traversing movement, if need be. On the bottom of the box is
arranged a grill formed by three curved blades covered with brass, where the
gunner places the projectile, tipping its wheelbarrow. Then he comes back to
the store with its wheelbarrow empty. The hoist placed on the left side of the
service platform, and firmly assembled to it, is a kind of noria. It is
composed by a sheet metal framework carrying two shafts : the lower shaft is
operated by means of two handles controlling a set of gears. It drives two
endless chains, carrying two grills like the grill of the waiting place.
Their curved blades run through the void space left by the blades of the
waiting place. Thence the projectile is seized and, pulled by the movement of
the chain, is carried to the loading place, where it is put down
automatically. The loading place, placed in the upper
part of the hoist framework, is composed by flat blades covered by brass and
a stop for the projectile. The stop is controlled by a handle, that lowers it
when the projectile must run to the thrower. In the same time it unlocks a
safety lock, that stops automatically the movement of the chain, when the
projectile is put down on the loading place, and blocks the movement until it
is not empty. i) The mask is composed by a thick shield
made of steel, cylindrical in shape, two lateral wings, and a roof. It is
bolted on the joints and the supports of the slide. Service of the piece. – The service of the gun
required four servants, two operators, and at least four shell-handlers : only three of them
nevertheless need a particular training, the other can be trained in a few
hours, and their action requires only good will and muscular effort. The servants
are : the aimer, the assistant aimer, the loader and the breech number. The aimer aims
and fires. The assistant
aimer operates the quick motion gear. The loader
operates the conveyor, throws the projectile, and introduces the bag
cartridges. The breech
number locks and unlocks the breech, primes, and aids the loader. The operators
operates the hoist. Two of the
shell-handlers supply the hoist; the other two bring the cartridge case backwards,
and give them to the loader and the breech numer. The overall
working is as follows : Let’s suppose
that the shot is fired, and the gun is returned in firing position. The
loader is rolling the projectile from the supplying place to the thrower. The assistant
aimer lowers the gun in loading position. In the same time, the breech number
opens the breech. When the breech is opened, the loader tilted the conveyor,
that is engaged into the gun axle. With the help of the breech number, he
throws the projectile, and introduces the the bag cartridges. Then he unlocks
the conveyor, and brings it back to the
loading place, where he deals with the filling of the thrower. In the
same time the breech number locks the breeck and primes, and the assistant
aimer operates the motion gear to connect the gun with the elevating gear.
When the breech number calls “ready”, the aimer, who has constantly directed
the line of sight on the target, fires. As seen, it can do it only when the
gun is connceted with the elevating gears, that is aimed to the target. The gun
recoils, then returns in firing position, and the loading operations restart. Thanks to the
mechanic safety devices of the gun, no mistake is possible. On the other
hand, owing to the easiness of the servants duties, to the little effort
required by the various loading and aiming operations, and to the
independence of these operations, it is easily understandable that the speed
of fire can be high. As it is said, it can attain rate of fire of 3 – 4
rounds a minute with well trained gunners. Taking account also of the great
power of the gun, we have to admit that the Schneider |
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III. Numerical references and data
SOURCE : This is the
translation of an advertisement of the French firm Schneider-Canet published
in 1908 (SCHNEIDER & CIE. Matériel
de côte. Canon à tir rapide de |