GUNNERY AND PROJECTILES
(RUDIMENTARY NOTES AND NOTIONS)
"The Prussian was born a brute, and civilisation will make him
GOETHE.
The apposite nature of this moral dictum could have been exemplified
in no degree more accurately, nor indeed remarkably, than in the light
of events which transpired during the forty odd years intervening
between the Franco-Prussian War of 1870 and the present-day world
conflict; events which may, perhaps, best be summarised as comprising
a persistent policy of unremittant and so-called peaceful penetration,
intense warlike preparation, and provocative "braggadocio," or
diplomatic bluff. Born in an atmosphere of arrogance and lust, imbued
with a spirit of savagery, the Hun stood forth at last in the blood-red
dawn of "Der Tag," naked, stripped of his pharisaical veneer of social
development.
"Vous ne devez laisser," wrote Bismarck in 1870, "aux populations que
vous traversez que leurs yeux pour pleurer," and clearly a decade of
"Civilisation" had sufficed to make his countrymen indeed ferocious,
to prove them obedient, albeit enthusiastic, disciples of the bestial
doctrine which he had expounded. No longer was the soldier alone to
be called upon to pass "half his time on the field of battle, and
half of it on a bed of pain"; civilian populations too, innocent old
men, defenceless women, young girls, and little children, all were to
be drawn alike, pitilessly, into the vortex; naught but their eyes
wherewith to weep remaining to them.
One has but to refer again to that arresting little volume
"Enseignements Psychologiques de la Guerre Européenne" (M. Gustave
le Bon) to be reminded of the pre-determined methods that were to be
adopted. "Notre principe directeur," Bismarck goes on to declare, "est
de rendre la guerre si terrible aux populations civiles, qu'elles-mêmes
supplient en faveur de la paix."
Four years of uncivilised warfare, of barbarity unprecedented in
the annals of modern history, have since taught us how terrible was
the meaning of these words, and if the possibility is conceded that
tragedy and comedy may, on occasion, run riot hand in hand together,
the climax was perhaps never more nearly approached that when in
August, 1914, the arch-criminal himself, Wilhelm II, that "born actor
and master of mis-statement,"[3] indited an agonising epistle to his
doddering confederate the Emperor Francis Joseph of Austria: "My soul
is torn," so ran this apostolic lamentation--"my soul is torn, but
everything must be put to fire and sword. Men, women, children, and
old men must be slaughtered, and not a tree or house left standing.
With these methods of terrorism which alone are capable of affecting
a people as degenerate as are the French, the war will be over in two
months, whereas if I admit humanitarian considerations it will last
years. In spite of my repugnance, I have been obliged to recommend the
former system."
[3] A comment of King Edward's on the German Emperor, 1906.
"In spite of my repugnance," however, or perhaps because of it, in
spite of or because of this recommended system of terrorism, the more
difficult it became to affect, to demoralise the "degenerate" French
people, the more seemingly impossible became the task of breaking
"those proud English hearts"; the war was not over in two months, in
fact, contrary to the prognostications of the "All Highest," it lasted
several years!
The nation, as it so happened, was never in more determined "bull-dog"
frame of mind; this determination moreover to "see things through"
"coûte que coûte" was amply voiced by Mr. Asquith, then Prime Minister,
at the Guildhall on November 9th, 1914--"We will never sheath the
sword until the military domination of Prussia is wholly and finally
destroyed," and floating back on the breeze away from the stricken
fields of France came echoing the refrain:--
"When the strife is fierce, the warfare long,
Steals on the ear the distant triumph-song,
And hearts are brave again, and arms are strong."
Dimly distant though the final victory might seem, fierce and
protracted though the strife, England continued unflinchingly pouring
forth her bravest and her best, while she herself, with a determination
grim and set, was of a truth turning "to swords her ploughshares," for
experience had taught her that the Prussian was born not only a brute
but a bully, and that the only way to deal with bullies was to hit them
back, to keep on hitting until they were down, and once down to keep
them there and prevent them from getting on their feet again.
But the maxim that "hesitation and half-measures ruin everything in
war" had never been lost upon the "Great General Staff of (German)
Imperial Supermen," who it might be opined had probably forgotten more
in the gentle art of preparation for war than we ever set ourselves
to learn. Gas shells, incendiary shells, tear shells, liquid fire,
clouds of poison gas, aerial torpedoes, floating mines, submarines,
mystery long-range guns, such were a few of the more obvious and less
humanly unspeakable horrors in which the common enemy had specialised.
Taken unawares, the question consequentially arose "How to hit them
back?" Man for man, fist for fist, we were sure of giving as good as we
received, and better.
"In bravery the French and English soldiers are the only ones to be
compared with the Russians," was the verdict of Napoleon. Bravery,
however, whilst being undoubtedly magnificent, is, on the other hand,
in modern warfare liable to become a constraining source of suicide
unless backed by commensurate means both of offence and of defence.
"The machine," as Mr. Lloyd George pointed out, when reviewing on
December 20th, 1915, the progress of events of the preceding months,
"the machine is essential to defend positions of peril, and it saves
life, because the more machinery you have for defence, the more
thinly you can hold the line. On the other hand it means fewer losses
in attacking positions of peril, because it demolishes machine-gun
emplacements, tears up barbed wire, destroys trenches." Again, "What we
stint in material we squander in life."
How criminal had been the lack both of prevision and of provision in
regard to meeting possible contingencies may be gathered from the fact
that on March 15th, 1906, Major Seely, M.P., in the House of Commons,
in moving a reduction in the Army Estimates (estimates which at that
time did not exceed the modest sum of sixty millions per annum), said,
"We could not afford to continue the present establishment, for the
House would not grant the money, and the country would not provide the
men."
The folly of it all was coming home to us with a vengeance.
Proportionate to the former mean and niggardly "cheese-paring" was
the resultant appalling rate at which life was now being squandered.
"We were short of all kinds of military weapons," Mr. Lloyd George
was forced to confess, "but the lack of high-explosive shell was
paralysing"; then as if in condonation of all former sins of omission,
"we believe that what is being done now to provide a supply of
munitions equal to all possible requirements will astonish the world
when it becomes known."
In this respect, therefore, it is, perhaps, not unnatural that interest
of a widespread nature should centre round Crewe, in virtue of the
quota of munitions which she, albeit unobtrusively, contributed to
the "world's astonishment"; indeed a certain sense of bewilderment
not untinged with pride cannot fail to supervene in the minds of that
vast section of the community, to wit the travelling public, and in
particular the great North-Western-loving public, when, the official
veil of secrecy being drawn aside, the mental faculty is free to note
and to assimilate the degree of resourcefulness, the versatility of the
locomotive engineer.
There is no concealing the fact that "the place acquired by machinery
in the arts of peace in the nineteenth century has been won by
machinery in the grim art of war in the twentieth century," but the
anomaly was strange indeed when Crewe, essentially the cradle of what
may perhaps be termed the _haute noblesse_ of locomotive progeny,
bowing to the dictates of stern necessity, extensively adapted her
domain to the novel effort of high-explosive shell production.
Manifold and great as are the instances which may be cited as evidence
of the strides made during the last decade in engineering science, no
other branch of that science has surely ever made appeal more alluring
alike to schoolboy as to popular imagination, than that embodied in the
modern British locomotive. Who in the course of his travel experience
has not happened at that "Mecca" of railway bustle and romance,
"Euston," the epic terminus of Britain's premier line, and focussing
with his eye the hazy limit of a far-receding platform, has not traced
the tapering profile of some distant-bound express, marvelling the
while that, harnessed on ahead, should be pent up a force eager,
impatient, yet withal so mighty that of a sudden, subservient to its
call, this elongated span of motionless inertia laden with living
freight should smoothly glide away, and gathering momentum on its path
with ceaseless rhythm, ever along, along and along, sweep towards the
far elusive line of the horizon? Yet this, in plain prosaic English,
was the ennobling vista opened through peaceful years of patient toil
and perseverance to the public ken, and dull must be the mind which
contemplates unmoved that splendid emblem of the locomotive world, the
awe-inspiring "Claughton" of that ilk, noble of mien and black of tint,
with breast-plate red, toying with trains the equal of 400 tons and
more, ticking aside the minutes and the miles alike.
[Illustration: "PATRIOT."--A TYPICAL EXAMPLE OF THE "CLAUGHTON" CLASS
OF 6 FEET 6 INCH, SIX WHEELS COUPLED EXPRESS PASSENGER ENGINE WITH
SUPERHEATED BOILER; FOUR H.P. CYLINDERS, 15-3/4 INCH BORE × 26 INCH
STROKE; BOILER PRESSURE, 175 LBS. PER SQ. INCH; MAXIMUM TRACTIVE FORCE,
24,130 LBS.; WEIGHT OF ENGINE AND TENDER IN WORKING ORDER, 117 TONS.
[_To face p. 99._]
Figuratively speaking, Crewe may perhaps be referred to as the "spill"
on which the face of the London and North-Western compass pivots; the
four points, north, south, east, and west, extending respectively to
Carlisle, London, Leeds and Holyhead; but familiar as are the scenes
of everyday activity throughout the entire length and breadth of the
Company's system, foggy, for the most part, are the notions as to the
phenomenal whirl of industrial enterprise daily in progress within the
precincts of Crewe Works.
Yet in these great engine Works (so menacing and unprecedented were the
exigencies created by this voracious war), 'midst all the multifarious
machinery and up-to-date appliances whereby is fashioned and evolved
in all its amazing detail that complex piece of mechanism, the very
essence of railroad itinerancy, the modern locomotive, was improvised
with a speed approximating that of the mushroom which springs up in the
night, a model and comprehensive plant, correlative with the multiform
processes involved in the manufacture of that swift harbinger of death,
the high-explosive shell, and its complement of grim appurtenances.
How paralysing was the lack of these shells may be gathered from the
fact that[4] "in the month of May (1915), when the Germans were turning
out 250,000 shells a day, most of them high-explosive, we were turning
out 2500 a day in high explosive and 13,000 in shrapnel." This gentle
reminder to a lethargic House did actually (so we are told) evoke
cries of "Oh," which latent degree of enthusiasm cannot be considered
exactly vulgar or ultra ebullient, when side by side with so depressing
a situation at home we endeavour to grasp the staggering figures as
set forth in the following French official statement:--"Our artillery
to the north of Arras fired in twenty-four consecutive hours 300,000
shells, that is to say, very nearly as many shells as were fired by
the entire French artillery in the Franco-Prussian War of 1870-71. The
weight of these 300,000 shells can be put at 4,500,000 kilos; or nearly
4435 tons. In other words, more than 300 large trucks were required for
carrying them by rail, or roughly half a dozen complete goods trains;
by road this would have meant 4000 waggons, each with a team of six
horses. The monetary value of these projectiles may be put at something
like £374,800."
[4] Mr. Lloyd George, House of Commons, Dec. 15th, 1915.
Prior to the summer of 1914, a shell, if not exactly an unknown
quantity, was at any rate one of these obvious, even if somewhat
curious things that might conceivably (in fact probably did) claim a
certain amount of attention from that rather spoilt and very exclusive
little clique, the professional army people. One read in the papers,
too, from time to time, that the Navy (that immensely popular though
slightly enigmatic asset of the Empire) was indulging in a little
target practice somewhere out at sea; this would mean the firing of
a few projectiles; but that was as it should be; we all liked the
comfortable assurance that we could "sleep quietly in our beds;"[5]
with an innate and justifiable sense of pride we liked, when occasion
permitted, solemnly to stand up and join in the refrain "Britannia,
rule the waves."
[5] The late Lord Fisher, Nov. 9, 1907.
Latterly, however, the "shell" has acquired so widespread a degree of
prominence, proportionate to the toll of human life and of material
damage that it has exacted, it has become in effect so commonplace
an object, hackneyed as the very chimney-pots of a jerry-built row
of houses, that a word of apology should perhaps be prefaced to any
additional allusion to a subject already so often cited, which might
otherwise and pardonably be regarded as superfluous.
Before diving, however, into any details as to the methods of
manufacture, it may be interesting to pause for a few moments and to
inquire into the nature of the mysterious movements of the shell when,
deposited by the artilleryman with tender and loving care safely and
securely within the breech of his gun, it flies away, the unerring
intermediary between him and the hated foe of an argument deadly and
convincing.
Our gunner experts (armchair no doubt as well as professional) will, of
course, tell us that the flight of a shell is gyroscopic, this possibly
in lucid contradistinction from that of the convex-shaped boomerang,
which, according to reliable information, is gifted with the graceful,
albeit inconvenient, art of returning to its original point of
departure. The shell, however, ere it quits the muzzle of the gun,
thanks to what is known as the rifling or grooving of the bore of the
gun, thanks, too, to the action of that indispensable little adjunct
familiarly known as the copper band, is imparted with the vigorous
twist, and once launched in mid-air spins round its longitudinal axis,
undeterred, like the gyroscope, either by force of gravity or by
atmospheric pressure.
This longitudinal spin is rendered eminently desirable, in fact
imperative, for various reasons, of which length and explosive capacity
of the projectile, accuracy in flight, diminished air-resistance in
proportion to weight, and finally range, may be quoted as the more
obvious desiderata.
The old ancestral cannon-ball, fired as it was from a smooth-bore
gun, had no means of acquiring this sudden longitudinal twist, and no
sooner clear of the muzzle, it found itself involved in the performance
of antics whimsical and capricious, turning over and over on its
transverse axis, head over heels, side slipping, looping the loop.
Again, the cannon-ball, being round, was limited in size to the bore
of the gun, so that in addition to the disadvantage just mentioned
of possessing no definite material degree of accuracy whilst on its
headlong course through the air, it offered the further disadvantage
of containing but a comparatively small explosive charge, and the
air-resistance it afforded in proportion to its weight affected
adversely, and in marked degree as compared with the modern
longitudinal shell, its range and potential destructive energy.
Reverting then to the modern projectile, and taking as a suitably
illustrative example the 6-inch high-explosive shell (for it was on
this particular type that Crewe was asked to concentrate), bearing
always in mind, too, that the modern gun is rifled or grooved and that
the effect of this grooving is to impart a vigorous longitudinal twist
or spin to the shell as it flies away, making it gyroscopic and almost
uniformly accurate, we notice that the length of this shell is eighteen
inches, thus exceeding the diameter in the proportion of three to one,
whence it becomes obvious that the capacity available for explosive
charge is proportionately greater than that of a cannon-ball of the
same diameter.
We next find that in place of the rounded wind-resisting surface of
the cannon-ball, the front end of the modern shell is pointed like
a pencil, the atmospheric resistance being in this way reduced to a
minimum. Decrease of wind-resistance naturally spells increase of
range, and in this connection tests have in the past been carried out
with shells having their bases as well as their noses pointed with a
view to obviating the vacuum which is necessarily created by the usual
flat base. A cigar-shaped shell, however, never proved satisfactory,
for like the Rugby football it was decidedly wobbly in mid-air.
How requisite was a superlative degree of accuracy and consequently of
skill in the manufacture of the modern high-explosive projectile may,
to some extent, be gathered from these briefly stated considerations,
and will become more apparent still when we come to glance at the
series of component parts of which the whole is built up.
Premature explosions, involving loss of life amongst the gun-crew,
the wrecking of the gun itself, not to mention resultant immunity from
dismemberment of those previously destined to be the recipients of
this unique form of greeting, are _primâ facie_ contingencies to be
guarded against; thus, owing to the sudden stresses to which a shell
is subjected on the firing of the propellent charge whereby inertia
becomes transmuted into velocity both forward and rotary, the steel of
which the shell is made must be of such tensile strength that not only
will the base-end withstand this transmutation, but the walls of the
shell must be capable of overcoming the inertia of the front end of
the shell, otherwise they will collapse, and a "premature" will be the
immediate outcome.
An output of steel adequate for all munition purposes was already a
problem sufficiently acute, and there were genuinely orthodox reasons
why the home output, in particular, should be maintained at as high
a level as possible. For one thing, it was eminently desirable that
America should keep supplied our Allies who were less well equipped
in "industrial and engineering resources than ourselves." "By home
manufacture," too, "we had saved in the course of a single year
something which is equal to 6_d._ or 7_d._ in the pound of income tax
in the metal market alone." Besides "when you order a very considerable
quantity of war material abroad, there is always a difficulty which
arises with regard to the exchanges and the gold supply." There was
also "the difficulty that you have not the same control over the
manufacturers of material abroad as you have got here" [Mr. Lloyd
George, House of Commons, December 20th, 1915].
Influenced by considerations such as these, Mr. Cooke undertook not
merely to machine _in toto_ a given quantity per month of rough shell
forgings, but proffered the extensive steel-making plant in Crewe
Works, comprising several furnaces of 20 and 30-ton capacity, both for
the supply of steel requisite for the initial manufacture of these
rough forgings, and if desired, for a further output of steel wherewith
to supply forgings to other firms engaged exclusively in shell
manufacture.
The output of 6-inch high-explosive shells from Crewe Works had, at
the time of the Armistice, reached, approximately, a total of 100,000,
and the corresponding weight of steel forgings may be estimated,
approximately, at 6500 tons. Government specifications in regard
to tensile strength and cold fracture tests were not unnaturally
exacting in the extreme, and the casts obtained at Crewe came fully
in these respects up to the standard ordained. But amazing though it
may seem (so tightly can the reel of official red tape be wound),
notwithstanding Mr. Cook's offer and ability to furnish this supply
of special high-grade steel, further Government regulations to the
number of seventeen and covering three pages of foolscap demanded the
observance of formalities, petty and extraneous, designed solely for
the purpose of securing the right of incursion within Crewe Works of
every Smith, Jones, and Robinson who under the pseudonym of "Government
Inspector," and as units of a hugely overstaffed officialdom, sought
by hook and by crook any and every means wherewith to justify their
overpaid existence.
"Nobody but managerial and supervising engineers can quite realise what
a handicap these people have been upon efficient production," writes
a student of bureaucracy in the _Morning Post_, April 21st, 1919.
"How the engineering industry has survived in spite of it is almost
a miracle; how it has produced in spite of it is quite a miracle.
At one time the Ministry of Munitions could boast of no fewer than
27,000 officials, nearly all of whose positions might be reasonably
defined as "jobs." There were inspectors and inspectors of inspectors,
super-inspectors, and inspector-generals, munition area dilution
officers, munition area recruiting officers, recruitment complaints
officers, and committees, directors, sub-directors, information
bureaux, with all the usual paraphernalia; officials with and without
designation, priority officials whose duties were as nebulous as their
qualifications, besides an unnumbered crowd of arrogant but grossly
inexpert experts. It is a splendid tribute to the industry that it
triumphed over this deadly deterrent and redeemed its obligation to the
nation under so cruel and undeserved a burden."
How Crewe Works survived in spite of this "handicap," this "deadly
deterrent," is explained by the fact that Mr. Cooke would have none
of these things; in fact, sooner than conform to the caprice and
tyranny of these "inexpert experts" from without, he very promptly
withdrew his offer of steel manufacture, politely but firmly consigning
"Major MacMarkfour" and "Captain Fitzgrazefuse" elsewhere, their
correspondence to the nearest wastepaper basket; a friendly chat with
the late Sir F. Donaldson, then Director of Army Ordnance at Woolwich,
sufficing to make it clear that at Crewe everything was strictly "above
board," and that the little entourage of professional experts within
justified the full and complete confidence which he, their chief,
reposed in them.
Not a few of the smaller engineering firms up and down the country,
faced with previously unconsidered problems created by the unlooked-for
transition from peace to war conditions, welcomed the call for shells
and yet more shells, as a ray of sunshine peeping from out the lowering
clouds of commercial stagnation. Hardly appreciating the fact that a
shell's a shell for a' that, and approaching the task with a flippant
disdain, akin to that of "selling seashells upon the seashore," some
of these good people, ostensibly patriotic and avowedly disinterested,
were soon asking themselves whether after all they had not bitten off
as much as, if not actually more than, they could reasonably chew.
The requisite degree of perfection in material, and of accuracy in
machining, was at the outset a sore puzzle to the many who had never
seen a field-battery in action, who had never inquired as to the
why and wherefore of the flight of a shell, who, by virtue of their
exemption from military service, never had occasion to congratulate
themselves personally on the subtle and unfailing precision of a
creeping "barrage"; and great was the vexation of spirit, many the
hours thrown away, legion the shells definitely consigned to the
scrap-heap (or perhaps at best set aside pending some seemingly
trifling rectification), ere aspirants to this novel and exacting
sphere of machine-shop art attained anything approaching the acmé of
perfection.
"It is better," wrote Napoleon, "to have no artillery at all than a
bad artillery that endangers the lives of men and the honour of the
nation," and selecting this fundamental principle as a basis on which
to build the fabric of his excursion into the then untravelled paths
of shell manufacture, Mr. Cooke made arrangements at the very outset
for his leading representative of the machine-tool department to visit
Woolwich, for the purpose, not only of acquiring first-hand knowledge
as to the most approved Government methods of producing shells, but of
making detailed dimensioned sketches from which to manufacture, in the
Company's own tool department at Crewe, the multifarious gauges, or
instruments, designed to verify in the most minute manner imaginable
the diverse form of the shell.
The consecutive operations through which the shell passes number some
thirty all told, and for each separate operation separate gauges are
required.
As emphasising not merely the delicacy of these all-important little
instruments, but the delicate proposition "up against" which he found
himself in his endeavour to discover firms who were capable of their
manufacture, Mr. Lloyd George confessed that "we found that some of the
shortage (of shells), if not a good deal of it, was due to the fact
that, although you turn out shell bodies in very considerable numbers,
you were short of some particular component which was essential before
you could complete the shell. It might be a fuse, it might be a gauge.
There was always some one thing of which you had a shortage!" Evidently
gauges were a source of considerable anxiety because "we therefore had
to set up two or three national factories in order to increase the
supply of these components."
By already possessing the necessary machinery for, as well as
considerable experience in, the art of gauge-making, Crewe was in
a position to ease very materially the burden of those Government
departments, those newly created "national factories" directly
responsible for the manufacture and the issue of gauges in quantities
sufficient to meet all demands, having merely to submit on completion
any inspecting gauges to the National Physical Laboratory at Teddington
for testing and stamping, prior to putting them into commission in
the Works. Further, Mr. Cooke, as a member of a "strong committee of
machine-tool makers" who were then "sitting constantly at Armament
Buildings in London," was specially qualified, in view of his inside
technical knowledge and practical experience, to assist in "directing
the operations of the whole of the machine-tool manufacturers of the
kingdom"; and finally, as Mr. Lloyd George went on to say, "the result
of all this" was "to increase very considerably not merely the output
of shells, but also the power at the disposal of the nation at short
notice to turn out even more than we have ordered if the emergency
demands" (The _Times_, July 29th, 1915).
The rough forging of a shell body, rolled and pressed to suitable
dimensions from a steel billet, is an uncouth-looking object,
resembling as much as anything one of those upright earthenware
umbrella-stands to be found in any cheap furnishing store; and with a
view to licking it into shape, to turning it as quickly as possible
into the smoothly finished article it was destined to become, Mr.
Cooke's representative, on his return from Woolwich, having, as a
preliminary, set in motion the machinery necessary for a supply of
gauges, forthwith proceeded to improvise a further series of machines
and tools, calculating the nature and number required for a given
output of shells per month, and mapping out a plan whereby the
various operations should follow one another from start to finish in
correct and regular sequence. How important is the strict adherence
to a regular sequence of operations is borne out by the fact that
a shell might easily be ruined in the event of any operation being
performed out of its turn. A convenient and suitable _locale_ in
which to lay out this shell-manufacturing plant was found available
in a previously unoccupied extension of the new fitting shop; and as
in the case of fuse manufacture at the old works fitting shop, so in
the present instance, members of the fair sex were destined to figure
prominently--a little band of neatly attired novices, some 150 strong,
speedily responding to the call, and ranging themselves under the
immediate supervision of a suitable quorum of expert mechanics of the
sterner sex.
[Illustration: 6-INCH SHELL MANUFACTURE IN THE NEW FITTING SHOP, CREWE
WORKS. [_To face p. 112._]
A multiple cutter-milling machine, formerly habituated to the
peace-time art of facing locomotive cylinders, suddenly found itself
saddled with a row of a dozen shell forgings, the open ends of which it
faced to a correct distance from the inside of the base. Thenceforward,
engine and turret-lathes deftly manipulated by our little friends of
the fair element bore the onus of the succeeding operations.
Ordinary engine lathes were eminently suitable for operations such as
centring, rough and finished turning, grooving and external blending
and turning copper bands. Then, thanks to the facility with which the
various tools can be swung round in the lathe-turret and brought to
bear on the work, turret-lathes were employed on operations such as
rough and finished boring, internal blending, recessing and facing.
Rough turning on a fluted mandrel, rough and finished boring, and
internal blending, in a concentric chuck secured to the face-plate of
the lathe, are operations quickly disposed of.
"Blending," needless to say, produces in the mind an impression of
smoothness and of harmony: smoothness unscored, that is, of the walls
and base; harmony complete between the two, and indispensable.
Into the finished and concentric bore of our projectile is now forced
a cleverly and home-designed expanding mandrel, a taper mandrel in
fact, which expands a hollow (and again concentric) bush, and on this
the base is centred. Transferred to an adjacent engine-lathe the shell
is fixed on a shorter three-bush expanding mandrel, and turned to the
correct and finished diameter. Removed to a turret-lathe, a slight
operation of counter-boring the mouth is performed; this is necessary,
as medical practitioners may be astonished to learn, for the purpose of
receiving the nose. The mouth is also faced, and screwed, but screwing
is effected on another instrument of torture, styled a thread-milling
machine; so prior to lifting the shell from the turret-lathe a recess
is cut in the far cavity of the mouth, this forming a clearance for
the thread-milling tool. The turret of the lathe having no transverse
travel, an ingenious little tool was designed and fixed into the
turret-head by means of which a transverse travel, actuated by a
hand-rachet and sufficient for the required depth of the recess, was
obtained.
Anything which is at all conducive towards the saving of time,
especially in war, is _ipso facto_ a device of the utmost strategic
and economic value. "Ask anything of me but time," once said Napoleon,
"it is the one thing I cannot give you." So, in the case of our
thread-milling machine, the saving of time effected is considerable.
The shell is as incomplete without the screw-thread in its mouth, as
it is without its nose; the thread has to be cut somehow; and by the
employment of a milling-machine and thread-cutter the job can be done
in about ten minutes as against an hour or more if done in an ordinary
screw-cutting lathe.
Having recourse once again to an engine-lathe, we attach a "form" (or
guide) plate to the slide-rest, to the profile of which the nose and
shell-body together are blended externally. As we are now nearing
completion, the next item on the programme is to see how we stand for
weight, and in the event of the shell being a trifle on the heavy
side, we either take a light cut off, reducing ever so slightly the
diameter, or else we shorten the base. There remain now the base-plate
and the copper band to complete the whole; the former is either
screwed or slipped with a plain circumference into a recess in the
base, riveted over with a compressed air riveter, and faced to the
required thickness; the latter is pressed hydraulically into a groove,
then turned and grooved to the required diameter. A kind of miniature
Turkish bath now awaits the long-suffering object of our commiseration,
in which it is steamed and cleaned, then placed nose downwards over a
tank. In this unenviable position a stream of varnish is generously
sprayed with a hand pump up its inside. Thereafter it reposes in an
adjacent chamber or stove until the varnish is thoroughly dried and
baked; whence emerging, a pneumatic tapping machine is waiting to
clear the varnish from the thread of its nose. It is then "boarded"
both in regard to weight and overall dimensions, and if passed "A1" by
the inspector proceeds into bond, where it remains until "called up,"
"reporting" at a filling factory, and in due course being "drafted
over-seas."
Prior to quitting the workshop's busy hum and reverting with our
mind's eye to the "battle's magnificently stern array," where we may
compare to further, if superficial, purpose the projectile and its
mathematically proportioned features with the somewhat violent form of
gymnastic exercise in which it is about to delight, a word or two in
reference to the evolution of the copper band may not be held amiss,
in view of the important _rôle_ it plays relatively to the shell as a
whole. The process by which these copper bands or discs were evolved
was unique, and inasmuch as it was possible to effect a considerable
economy by the evolution of three separate and distinct bands from one
original sheet or square of copper, Crewe became responsible not only
for the bands components of the 6-inch shell, on the manufacture of
which she was exclusively concentrating her endeavours, but was able
concurrently to produce for other firms further bands components of
both 8-inch and 4·5-inch projectiles.
Equally with the fuse or gauge, the copper band ranks as one of those
"particular components which are essential before you can complete the
shell," and in order to preclude in so far as lay in his power to do
so the possibility of any shortage of this particular component, Mr.
Cooke put in hand and had completed within a fortnight from the date
of commencement an entirely new hydraulic press having a capacity of
130 tons and a working pressure of 2000 lbs per square inch, by means
of which copper cups were pressed out to approximately 700 per day,
and from these cups were cut and turned bands of different diameters
according to the size of shell for which they were required; the total
number of copper bands thus manufactured at Crewe at the time of the
Armistice being upwards of 700,000.
The method was simple when once evolved. The 8-inch band being of the
largest diameter of the three was the first to be dealt with, then the
6-inch and finally the 4·5-inch. A piece of flat, square copper plate
was first dished in the press by means of a solid punch, to the shape
of a shallow bowl; annealed, it was pressed a little deeper; annealed
again, the process was repeated a third time, but deeper still, the
dish becoming a cup; and in order to obviate the drawback of the walls
of the cup clinging to the circumference of the solid punch, a cleverly
contrived split and collapsible punch was introduced, that is to say
a punch which, on being pressed downwards, was expanded by a taper
wedge to the full diameter required, and which, on being withdrawn,
collapsed or shrank inwardly in proportion as the taper wedge preceded
and automatically withdrew the expanded and circular sides, the latter
disengaging simultaneously from the walls of the cup.
Transferred to the fitting shop, a band or disc 8-inch diameter
was turned and cut off from the cup, the latter returning to the
press, where through the medium of similar punches of requisite and
correspondingly smaller diameters further operations resulted in the
evolution of cups from which were turned 6-inch and 4·5-inch bands
respectively and in sequence.
The proportionate number of bands cut from the three sizes of cups
were, as a general rule, three from the smallest or 4·5-inch, eight
from the intermediate or 6-inch, and one only from the largest or
8-inch, and it was in some measure due to these circumstances, due, no
doubt, too, to a certain difficulty in obtaining delivery of copper
sheets in sufficient quantities, that for the purpose of increasing the
output of 8-inch bands and of maintaining this output on a level with
that of the two smaller sizes, recourse was had to the brass foundry,
where it was considered practicable to cast the bands, especially in
view of the amount of copper scrap of both shearings and turnings that
was available for melting-down purposes.
A certain amount of preliminary experimental work was perforce
entailed, both for ensuring that the band, when cast, should exhibit
an estimated degree of shrinkage (for the greater the shrinkage the
sounder the casting, a shrinkage of 1/4 inch being usually accepted
as a minimum), and that the metal should be capable of withstanding
certain specified Government tests, the one condition, of course,
being contingent on the other. Tests which were actually made proved
wholly satisfactory, the average results being an elastic limit of 7·5
tons per square inch, an elongation of 45 per cent. on two inches, and
finally a breaking stress of 14·5 tons.
De-oxidisation, that is to say the process of removing oxygen from
the metal for the purpose of obtaining castings that were sound, free
of blow-holes and of oxide of copper, was effected by mixing a small
percentage of phosphor-copper with the molten copper in the crucible.
Boron-copper was also tried as a de-oxidiser, but no real advantage
was noticeable. Comparative tests, too, were made for the purpose of
ascertaining the percentage of loss of copper when melted in crucibles
and again in a reverberatory furnace. The former process resulted
in a loss not exceeding 3/4 or 75 per cent.; whereas the latter was
responsible for a 7 per cent. loss. Any saving which came within the
meaning of the word "economy" as completely removed and distinct from
that of "parsimony" was a precept not merely preached but extensively
practised throughout the locomotive department at Crewe, and as an
illustrative instance of this praiseworthy, and therefore patriotic,
policy the casting of copper bands may be cited.
Although cheaper and possibly less reliable methods of producing copper
bands may have conceivably come into being during the final stages of
the war, it was obvious to even the least well-informed in such matters
that, provided a mixture could be obtained whereby the metal could be
relied upon to pass the Government tests, the process of pouring molten
copper from a crucible into a sand-cored cast-iron chill was likely to
be at any rate cheaper than that involving the employment of presses,
rolls, shears, and punches.
On comparing the estimated cost of manufacturing copper bands by the
pressing and casting processes respectively, a difference of one
shilling per finished band was shown in favour of the latter system;
and although it may seem a mere bagatelle, a drop in the ocean of
squandered millions, to those who not merely are encouraged, but who
encourage others, in the art of reckless and profligate extravagance
when handling the public purse, this modest shilling per copper band
saved represented an aggregate of £1750, a sum not altogether to be
sneezed at when we consider that the value of the 35,000 bands cast in
Crewe Works was but an infinitesimal fraction of the total munition
expenditure during the war.
We are told that "the use of travelling is to regulate imagination by
reality, and instead of thinking how things may be, to see them as
they are." Hence it has been, we may confidently aver, for the purpose
of seeing things as they are that we have availed ourselves of this
opportunity to fathom in some measure for ourselves the abstruse art of
shell-manufacture as practised in Crewe Works. The imagination, however
morbid and obtuse, can hardly fail to be stirred when pondering the
rotund and rudimentary profile of the rough shell-forging lying with
all its latent possibilities, recumbent in the lathe; ultimately in
its finished form _c'est cela_,[6] the shell we meditate, _qui va nous
débarrasser des Prussiens_; thanks now to that generous impulse which
prompts our gallant gunner-men, good fellows all, possessed of "mildest
manners with the bravest mind," to unravel for us the all-absorbing
mysteries of that sphere of "war's glorious art" in which they
themselves excel, reality will regulate our questioning imagination
as we follow them to the dim seclusion of some cleverly camouflaged
gun-emplacement.
[6] _C'est celui-la_, etc., said of the Tsar, Nicholas II., when
visiting Paris in 1896.
We have already seen that the motion of a shell is rotary as well
as forward, this rotary motion being brought about by the joint
instrumentality of the grooving of the bore of the gun and of the
copper band on the shell.
Another and very important function performed by the copper band
approximates to that of the piston-ring of a locomotive cylinder, which
prevents the passage of steam from one side of the piston to the other.
Concomitantly, the copper band, turned a fit in the bore of the gun
and jammed into the rifling, is designed to obstruct the passage of
the propellent gases beyond the base-end of the shell; these gases are
naturally imbued with a habit or hobby of gnawing away, or eroding,
any metal surfaces with which they can come into contact, so that the
further they can penetrate up the bore of the gun, the more material
damage that will ensue, and the rifling becomes proportionately erased
or eaten away. Further, owing to the fact that the degree of heat
generated by the ignition of the propellent charge is obviously most
intense in the area most adjacent to the base of the shell, erosion
becomes patently more pronounced here than in other directions;
consequently as the area in which the propellant gases are exploded
increases, so the pressure exerted by these gases decreases, the net
results of these considerations being loss of accuracy and of velocity.
Different civilised communities favour different kinds of explosives
as a gentle means of attaining their ambitions, and these explosives
may be solids, liquids, or gases. In this country picric acid (or,
tri-nitro-phenol), and tri-nitro-toluene (or in its abbreviated
and more easily pronounced form "T.N.T.") are the two kinds most
extensively adopted for the filling of high-explosive shells. Owing,
however, to certain unexplained caprices in which it is known to
indulge, owing, too, to the fact that persons employed on its
manipulation have died from the effects of trotyl poisoning, T.N.T.
is less extensively employed, in spite of certain known and obvious
advantages which it possesses over picric acid.
Picric acid solidifies after being run in a molten condition into the
shell, and every precaution has to be taken in order to prevent, during
solidification, the formation of cavities, because the least tendency
to friction that might occur due to the "setting back" of this hard
explosive mass resultant on the sudden forward movement of the shell
might easily give rise to a "premature." Herein we recognise the vital
importance of wholly harmonious internal blending, absence of which
might prove a further source of friction entailing imminent peril
to ourselves as we stand beside the gun. Again, picric acid is ever
seeking opportunities for combining with metal, whereby compounds of
a nature most sensitive, and styled "picrates," are created, and of
which the most sensitive is the lead-picrate. Hence we breathe a silent
prayer that not only has the shell's inside been sprayed in the most
efficacious and thorough manner possible, but that the composition of
the varnish itself is entirely lead free.
Our wives, our families, our friends, we fain would turn to them as of
a sudden a fresh suggestion, fraught with peril dire, creeps from out
some hidden corner of our timorous mind.
On the firing of the propellent charge, the expanding gases, we are
told, cause expansion of the gun, thereby simultaneously allowing
proportionate expansion of the shell. We know already that erosion
is most pronounced round the area within which the propellent charge
is fired, that is to say, just at the commencement of the rifling of
the bore; hence we see that in all probability the bore decreases
gradually, even if imperceptibly, in the direction of the muzzle.
We have, however, had experience of these varying and imperceptible
degrees of graduation at Crewe, measuring them with our plus and minus
gauges. What, therefore, if the shell, expanded in the commencement of
the rifling, jams, or is momentarily checked, in its passage up the
bore? A "premature"; for the pellet in the fuse is probably already
free to jump forward against the detonating needle. These nightmare
prematures! Thank goodness, after all, in one direction, at least,
assurance has been rendered doubly sure; we used to wonder why all this
fuss and trouble about a base-plate? Now we understand. Imperceptible
must be our attribute again; metals are porous, imperceptibly so. Now
imagine a sieve trellised with wires finely drawn as the threads of a
spider's web, threads so closely woven and interlaced that only the
most minute "teeny weeny" holes remain, a sieve in fact which though
porous is not even transparent. Figuratively speaking this is the base
of a shell-forging; a porous partition, the sole dividing line between
the ignited propellent gases behind, and the high explosive bursting
charge within the shell; in other words, between ourselves and "kingdom
come"; hence our supplementary or protecting plate, the grains of whose
metal run crosswise to those of the shell-forging base. By this method
of reinforcing the shell-base, the odds in favour of a "premature" due
to the penetration of the propellent gases to the explosive charge are
reduced to a further irreducible minimum.
The gun is, of course, designed to withstand the pressure within the
breech and behind the shell, exerted by the firing of the propellent
gases; this pressure naturally varies according to the size of the gun,
and decreases proportionately as the shell shoots forward towards the
muzzle with rapidly increasing velocity.
When, however, we come to consider the pressure exerted by the
detonation of the high-explosive charge within the shell itself, and
the velocity acquired by the resultant explosive gases, we are apt to
fidget about a trifle uneasily in spite of our efforts to remain at
least outwardly cool and nonchalant.
All the same, a matter of 300 tons per square inch, which is the
pressure liable to be exerted by the detonation of an average charge
contained within the high-explosive shell, can only be explained as
"splitting"; and when our genial gunner-friends further assure us
that 7000 metres or 21,000 feet per second is the velocity resulting
from the detonation of "Trotyl," "staggering" is perhaps the most
fitting epithet, and an American "Gee whiz" the only coherent sign of
comprehension of which we are capable at the moment. For supposing a
"premature" did chance to occur; well...! Mercifully enough perhaps
for them and for their peace of mind, these intrepid individuals the
gunners have little or no time, as a rule, to reflect upon the naked
meaning of these figures and their attendant possibilities; for as
Kipling has sung--
"The moril of this story, it is plainly to be seen,
You 'avn't got no families when serving of the Queen--
You 'avn't got no brothers, fathers, sisters, wives or sons--
If you want to win your battles take an' work your bloomin' guns."
The success emanating from the working of our "bloomin' guns" has been,
it may be fairly argued, in no small measure due to the excellent
qualities of the high-explosive shell, and some interesting figures in
this respect may be usefully quoted from the _Daily Mail_ of May 16th,
1919:
"Remarkable comparative tests," runs the briefly worded paragraph in
question, "have been carried out by British gunnery experts with the
high-explosive shells used by both sides in the war. The shells from
captured and Allied dumps were fired from the guns for which they
were made at specially prepared targets. The official record of 'duds'
(shells which failed to explode) was--
United States 50 per cent.
German (1918) 38 " "
French 32 " "
Italian 25 " "
Austrian 25 " "
British 8 " " "
The remarkable results obtained from the British standpoint as compared
with that of other and competing nationalities confirm once again the
service rendered by our modest little friend the shell "gauge"; and
without in any way disparaging the imperturbable _sang froid_ of our
gunners, or the indomitable courage and the unquenchable _flair_ of our
splendid infantry, it is no exaggeration to say that the superlative
degree in the art of shell manufacture attained by British exponents
has been largely instrumental in enabling us to fulfil the pledge that
"however long the war might be, however great the strain upon our
resources, this country intended to stand by her gallant Ally, France,
until she redeemed her oppressed children from the degradation of a
foreign yoke" (Mr. Lloyd George, October, 1917).