THE 155-MM FILLOUX GUN.
WEIGHTS, DIMENSIONS, ETC.
Weight of Gun including breech
mechanism 8,795 lbs.
Length 232.87 inches.
Caliber 155-mm (6.1042 inches.)
Muzzle velocity 2,380 ft.-sec.
Rifling, one turn in 2.989. Caliber,
right hand uniform.
Weight of projectile 95 lbs.
Maximum range 16,200 meters.
Weight of maximum powder charge 25¼ lbs.
Weight of carriage 11,065 lbs.
Weight of gun and carriage, complete 19,860 lbs.
Diameter of wheels 1,160mm.
Width of track 2,250 mm.
Height of axis of gun 1,482 mm.
Elevation 0 to 35 degrees.
Maximum traverse 60 degrees.
Weight of limber complete 3,190 lbs.
Weight of gun carriage and limber 23,050 lbs.
The distance from center line of
carriage axle to center line of
limber axle, approximately 4,500 mm.
[Illustration: _155 M.M. GUN_ _MODEL OF 1918_ (_FILLOUX_)]
_The gun_ is of the built-up type and consists of the tube strengthened
by the following jackets and hoops beginning at the breech end: The
breech ring, the jacket, the hoop A, the hoop B, the clip hoop, the
clip hoop set on the hoop B and the muzzle bell. The length of the gun
from the muzzle to the breech base is approximately 18½ feet.
A recoil lug on the underside of the breech ring provides means of
attaching the recoil and recuperator rods. Hinge lugs for the breech
are also formed on the breech ring. Bronze clips to serve as guides in
the cradle are screwed to the sides of the jackets.
_The breechblock_ is of the interrupted screw type, having four plain
and four threaded sectors. The breech mechanism is of the plastic
obturator type, having the forward mushroom-shaped head of the
breechblock equipped with the asbestos ring, known as the obturator
pad. Upon firing, this ring is compressed and acts as a gas check to
prevent the leakage of powder gases back through the breech. It has
sufficient resiliency to resume its original form after firing. The
firing mechanism is of the French percussion primer type which is
described under “155-mm Schneider howitzer” and is interchangeable with
the guns enumerated therein.
_The cradle_ is a steel forging pivoted by trunnions in the trunnion
bearings of the top carriage. It is bored with three parallel cylinders
for housing the recoil and recuperator mechanism. On its upper side are
slots for the gun slides and the elevating rack is bolted to the lower
side.
_The recoil mechanism_ is of the hydro-pneumatic variable recoil
type. The larger of the three cylindrical bores in the cradle block
contains the recoil mechanism; the two smaller ones, the parts of the
recuperator mechanism.
[Illustration: 155 MM GUN CARRIAGE MODEL OF 1918 (FILLOUX)
LONGITUDINAL SECTION IN BATTERY]
_The recoil mechanism_ consists of a piston and piston rod and a
counter rod. The piston rod is connected to the breech lug and,
therefore, recoils with the gun. Grooves of variable depth are
milled along the length of the counter rod, controlling the flow of
oil through the ports of the piston during the recoil. This counter
rod assembles within the bore of the piston rod. It does not move
longitudinally, but rotates. The amount of this rotation changes the
area of the orifices through which the oil can pass. Its rotation is
accomplished as the gun is elevated by means of an arm and gear sectors
in such a manner as to shorten the recoil as the gun elevates.
A replenisher or gravity tank is provided in connection with the recoil
cylinder which assures the recoil cylinder being full at all times
and also takes care of any expansion of the oil due to heating. Its
capacity is about 17 quarts.
_The recuperator mechanism_ consists of two connected cylinders, one
containing the piston and piston rod which are attached to the breech
lug, while the other contains a mushroom valve and a diaphragm. The
diaphragm separates the oil contained in the first cylinder and part
of the second cylinder from the high pressure air which compels the
return of the gun into battery after recoil. Normally a small amount of
oil must be between the valve and diaphragm. Oleonapth is the liquid
used in this recoil mechanism. The amount of oil in the recoil and
recuperator mechanism is shown by an indicator so that it can always be
seen whether or not they need filling.
_The top carriage_ is a large steel casting mounted on the bottom
carriage on which it pivots to traverse the piece.
The handwheels and mechanism for both elevating and traversing, are
mounted on the top carriage. The tipping parts are carried on the
trunnions of the top carriage.
Belleville Springs carry the weight of the gun when traversing, but on
firing the springs compress and the firing stresses are taken on the
bearing surfaces between the top and bottom carriages.
The bottom carriage is a large steel casting suspended from the axle
(in traveling position) by a heavy multiple leaf spring. It supports
the top carriage, houses the axle and provides hinge connections for
the trail. When firing the axle is unshackled from the left spring and
the bottom carriage bears directly on the axle.
_Traversing_ is accomplished by turning the top carriage which pivots
on the bottom carriage. This is done by means of a rack and train of
gears which are operated by the handwheel on the left side of the
carriage. A traverse of 60 degrees, 30 degrees right and 30 degrees
left, is possible.
_Elevating_ is accomplished by a rack on the cradle operated through
gears by the handwheel located on the gear box at the left of the top
carriage. Elevations from 0 degrees to 35 degrees can be obtained.
_The trail_ is of the split type and consists of steel plate beams
of box section. Locks are pivoted at the forward end of the trails
for securing them in the open position. When closed together they are
clamped and attached to the limber. A traveling lock is provided on the
trail for retaining the gun in retracted position.
Two types of spade are pivoted, one for soft and one for hard ground.
When traveling the spades are always removed from the trail.
_The wheels_ are of cast steel, each wheel having two solid rubber
tires.
Wheel shoes for traveling over soft ground are provided, which assemble
over the rubber tires. They consist of twelve plates for each wheel
which give a broad bearing surface under the wheel. The wheels are
equipped with band brakes.
_The sighting equipment_ is exactly the same as that described with the
155-mm Schneider howitzer.
_The ammunition_ used is of the separate loading type. Either shrapnel
or high explosive steel shell is used, as well as gas shells and other
special ammunition. The projectile weighs 95 lbs. The propelling charge
of smokeless powder is a sectionalized charge made up of two sections;
a base charge and one smaller increment. The weight of the charge is
25 lbs.
The fuzes commonly used are the 31 sec. combination fuse for use
with shrapnel and combining time and percussion elements: the point
detonating fuse Mark IV used with the steel high explosive shell and
the mark III point detonating fuze used with gas shell.
[Illustration: 155-MM. HOWITZER CARRIAGE, MODEL OF 1918 (SCHNEIDER).
TRAVELING POSITION.]
[Illustration: 155-MM. HOWITZER CARRIAGE, MODEL OF 1918 (SCHNEIDER).
RIGHT SIDE VIEW.]