WAR MUNITIONS

Dominion, Volume 8, Issue 2576, 25 September 1915, Page 12

WAR MUNITIONS

MANUFACTURE OF SHELL WHAT WE MIGHT DO ' - ' ■ .■ . p '■ (To the Editor.)' Sir,—Much lias been said and written concerning tlio practicability or'impracticability—principally the ... latter—of manufacturing shell in tho Dominion. It has frequently been _ averred, both individually, and at . meetings of the industrial association and 1 other bodies, tliat "nothing can be done.". Firstly, because we .have no suitable material, and, secondly, because we have no suitable, machinery. .. 1 will not hero dwell Upon the former part of the plea because two large firms ill Australia, possessing steel-making plants,, have,, undertaken to manufacture steel of tho requisite nature, and to supply such to tho .Dominion.. There is, therefore, every reason to believe that the material (steel) difficulty is more imaginary than real, and that wo shall be able to obtain steel -without delay and without going outside the Eiiir pire. It ivould; of course, have been tar moro satisfactory for us ;to have Made our own steel from our immense (leposlts of very pure iron ore/but that is a matter which:is to come—and I. think sooii. In the meantime there is nothing to prevent the 'Dominion making high-class steel from imported pigiron, for—and this is a fact which. seems always to be overlooked—we possess small but up-to-date steel-making plant. The public will, I feel,'.be more interested in', learning the facts that shell can bo and has already been made—and .this quite.satisfactorily—in the Dominion, and that such ' shell—made under regrettable and■ adverse circumstances— lias been found to be. of .highly commendable accuracy of 'workmanship, and, moreover, has proved satisfactory under actual gun fire. ■ The facts, are. as ..follow: A certain mechanical engineer, possessing a small works, volunteered to lnakg up sonic sample shell. .. He did so because ho had been engaged in the manufacture of shell—many/thousands of them havihg passed through his hands—in one of our largest steer works at Home, and knew himselF to possess all necessary knowledge and experience for carrying oiit tho work. The. Commandant of the New Zealand. Forces received this effer in tho right.spirit; he encouraged, the manufacturer to proceed, and directed that all things necessary and all available facilities 'should be furnished him. Tho 'manufacturer asked for very little, namely a: shell to copy from and a piece of steel to make from; Let Us see' how this-.staple request was complied with ? Tlie manufacturer chose to commence with a 4.5 shell— weighing about 351b., and thus being about twice as heavy as the 18-poundera for which our Armies havo such urgent need. Ho took the sample shell back to his works, and promptly produced a replica: ■*.' . a.

' At ! this .time.(in June) I was being asked by the presidents of the Chambers of Commerce, tlio president of the Industrial Association, and others to approach the Defence Department, and tb ascertain what was. beiiig; done, and what could possibly be done in the matter of tho Dominion assisting, tho Mother Country, in' tho manufacture of munitions; me in touch with the .Minister, and also with'Briga-dior-General Robin, who extended to mo the same courtesy; he oyinced tho same energetic, desire to help in tlio matter, and ho - made tho, excellent suggestion that if I called together a meeting of Wellington engineers to consider the matter lie Would attend, explain,- and assist with everything' in his power. All this, as is liow'known, was prompt-, ly carried out, incidentally General liobin informed me of what was being done in tho matter of the locally-mado 4.5 shell, and courteously invited me'to be present at the test.. • : ..

Now, I need not' point out —even to. non-technical' readers—that, tho steel required to "withstand the enormous pressure of guu-firo . . and ; (in tho case of shrapnel) that of the .internal bursting charge.without either, becoming crumpled up, by the former or tearing open from the latter, must bo both suitable- ill its nature and of tho -highest quality. Accordingly, upon my being introduced to Mr. Geo. Birch, the maker of the. shell, on board the Janie Seddon; as we proceeded across tho bay to test iti I naturally asked liim "What steel he had mado his shell from? What was its cneniical composition, its tensile strength, its crashing strain?"' etc. .Judge ;of my when I was informed that all of £heso thiiigs; were unknown. I have since been informed tliat the shell was made from a piece of steel,of unknown quality and' unknown, origin picked up in a Wellington foundry. lam afraid I wa ! s guilty ; of the impolite remark that ha had. committed a grave error—a sentiment iu which Mr. Birch is now in perfect accord with. m»..

It being inconvenient at the time to .try'the sliell in_ a/gutt. it was Exploded jn a trench, with the result that, although its head .bloiv off satisfactorily and in the manner desired, its body was torn up the side as it Ehould not 'have, been, but which, nevertheless, is quits frequent with service ■ shell. Examination showed that the steel'from which this shell had beeu niado was utterly unsuitable, hence valuable . time was wasted. . ; '. ... . _ Nothing , daunted— on. the part of either party —the General is reported to have said: "Don't let that worry you, but'go and make some 18-pound-ers." Despite the fact that Mr. Birch had made special tools for turning out the 4.5 shell, lie immediately complied. I fancy, at this stage, I can hear the public saying "Surely every precaution possible was taken to ensure that these (second batch) shells should be inado from suitable steel," Let us see what happened! There being no shell-steel available, Mr. Birdh stipulated that lie should be supplied with "a piece of | railway axle. 36 inches long, and forged (hammered) down to 3 V inches- in diameter." ' Jh doing this Mr. Bircli did' a sensible thing, but the Department, it appears, did- a senseless thing—-in-deed, it has been suggested that it was guilty of culpable neglect; neglect involving the possibility of serious damago to a valuable gun. For we find that in'duo courso a piece of steel — presumably of the description and quality asked for, and having been treated "as promised—was furnished to the manufacturer, without comment or referenco tdK'lio brand or quality.

' Will it ho believed that upon examination' Sir. Bircli found that it was not railway axle steel at all? That it had not been forged'down, and that, in fact, it was. nothjng more or lens than 3 feet, of ordinary "merchant bar" ? These regrettable facts _ were laid before the conference of engineers of Government .Railways, who will doubtless inquire into how this thing came to'happen.' Wo now find. Mr. Birch-, in his patriotic zeal to assist with his practical experience, committing a further indiscretion (as he 'has readily admitted to mo), for ho at- once set to work—for the second timo-Ha' make shell out of unsuitable material. So rough was tho "merchant bar" and so deeply scored that he found himself unable to make a satisfactory job of' moro than ouo shell out of the length of steel, supplied for three. . This shell, which was a thoroughly workmanlike production, accurately true to dimensions, and of good appearance, was'-brought over by the Ma,yov of Blenheim, and exhibited in the House of Representatives. In the meantime Mr. Birch, by .re-chuck-iug, just: managed to.produce the two

other shells out of the "merchant bar," which lie had previously discarded. It was then arranged to test these shell by gun-fire on the range at Trentliam. Questions wero asked iu the lloiiso, and permission granted to members' of Parliament to bo present. In, duo course a goodly party assembled at Trentham for the test, ainongst whom were > some dozen members- of the House, ~ including tho Speaker. Prior to the tests, Brigadier-General Robin addressed words of explanation to_ those present,, amongst; other thing's, pointing out that 1:ho fired shells ought to bo found, with their heads blown off but with their bodies intact. Tlio ros.ilt-s appear to have been as follow; —A total of six shells was fired: of these three were recovered.: Two had beon brokeu into pieces, (which they should liot have been), whilst tho third had remained intact wijth its hoad (which again it shohld not'have done), the only thing which had happened to it being that its noso plug had blown out, and through this aperture the bullets had escaped.- In other words, none of the service shell behaved properly. That the head of the ono whose body remained intact had not blown off was attributed to the fact that it was incomplete, its diaphragm never having been inserted during the process of manufacture. That this should have been the case oceasiouod surprise, and Colonel Campbell, Commandant of Coatt Defences. who was present, thought that it might be advisable to cable the Homo authorities and to ascertain if diaphragms had been discontinued. I have to-day carefully discussed this letter with Colonel Campbell, who repeated his advice that this information should be asked for now that it is contemplated to manufacture shell in large _quantities in the Dominion. The remaining service shells had diaphragms, but these also behaved unsatisfactorily'because . they broke right up, whereas the heads alone should have blown out.

Turning to the locally-made shell, of tho three fired one was picked up. This was found to have its body complete, whilst its head had been sheared off by the bursting charge exactly in accordance with requirements. Of another, only a portion of the head was found. Examination of this proved that the shell had behaved properly," its head having sheared off as required of it. The. body of this ha<s so far not been' found. Neither has tho third locally-made shell been recovered.: This proves that it did not by reason of breaking -up—as had been the case with the service shell —otherwise the fragnjpnts remaining ,'upon tho ground surface ,would have been picked .up. The one Imperial shell which remained intact (improperly) and the one locally-made shell (with head properly blown off) wore dug up from' two feet beneath the ground. This refercn.ee to the report, which has beon published elsewhere, and statements of facts, must, of course, not be taken as a reflection upon the Imperial shell. No useful purpose would be servetl_ thereby, for, as Colonel Campbell' pointed out, it matters not what precisely tlio action may be so long as we can rest assured -that all shell used, no matter, where manufactured, is capable of properly fulfilling its proper and allotted purpose of destructions' (Sut, what is of great importance is that those who are about to enter upoii the manufacture 'should know clearly the' requirements they have to fulfil. There is' nothing, to be gained by either ; secrecy or reticence—but. the reverse—for wo haye set out to . vanquish- our enemies, and-if it should come to their ears that we are in deadly earnest and are malting preparations—as they have- done— to do so in a businesslike and deadly manner, so much the -better. Our enemies indeed by their air raids in the Old Country are murdering .our men, woman, and children with this very object in view.

Per contra, it should'be pointed out that the locally-manufactured shell winced a shortcoming, in that the fired shell—which had not been painted as it should, have i, markings from the gun .rifling, just in front of the driving band, due to a slight "settingup" from the discharge. That it did not do so to a far greater extent is quite remarkable in view of'the improper steel employed.. , ■

In explaining to manufacturers what they 'would be called upon to comply with in regard to accuracy of workmanship, a certain authority—very , properly —pointed o.ut that shell (according to War .Office-" regulations) is required to be turned to a ceitain limit of . . error, which • he stated to bo a thousandth of .an inch, mentioning that in regard to such high-class work as locomotive building one hundredth of an inch (or one-tenth of this accuracy) was regarded as satisfactory. This might cause a feeling of despondency upon the part of the would-bo manufacturers. But we have to remember that—in the hour of our Empire's need—girls and women (as the British Prime Minister pointed out), domestic servants, dressmakers, barmaids, gentlewomen, all are to-day turning out shell within these limits; as photographs of them engaged in this work attest. ,

It is, therefore, interesting and important to ascertain hoi/ far this assumed accuracy is carried out in actual practice. For tliis purpose 1 have calipered tlio sample shell which was supplied to the manufacturer to be copied from, and I'find that-this accuracy was very, very far from having been observed. Inaccuracy in regard to tho most important dimension, that of the thickness of the wall, was clearly perceptible to the unaided eye. I subsequently obtained two independent reports upon these dimensions, kindly furnished to me by Wellington men, who had been engaged ;in high-class work and munitions-making in tho Old Country. The findings'are identical, and may, bo summarised thus:—-Dia-meter'nf base 3.205, same measured at right angles 3.293 (i.e., base of shell was not'round: wanting in truth by 'two-thousandths); diameter at shoulder 3.281, same measured a{- right angles 3.271 (i.e., the case was not round by one-hundredth of an inch). The thick-' ness of the ease varied by .023 (i.e., the boring was eccentric,. and tho thickness of the wall varied •' by twenty-threc-tliousandtlys). Thus in the most important dimension the shell was twentythree times less accurate than, according to tho authority above referred to, it is required to be. '

Tho authority referred to, however, singularly failed to observe accuracy His statement that shell must be turned true to a thousandth of an inch is entirely wrong,. and, therefore, unfortunately; quito misleading. ' Had he taken tho precaution to carefully, peruse an officially-dimensioned drawing of a shell lie could not liavo fallen into this error. . Tho faots aro these: A "tolerance" or certain specified "limit of error" is permitted Mid provided- for. The amount of tho "tolerance" depends upon tho importance of the dimension to which' is applies. I will giro an example, confining, myself to the 18-pounder and taking the most important dimension—its diameter. This will suffice to make this important matter quito clear to manufacturers and public alike.

Tlie diameter of on 18-pounder is 3.255, plus 0.005 or minus 0.005; That is to any, if ,bo either fivethousandths of an hich too large, or five-thousandths of: mi_ inch too small. In other words, a variation in size of ten-thousandths of an inch is allowed. But ten-thousandths of an inch equal ona-hundrodth of an inch. From this it will.be seen that (a)'tho authority in question mis-stated tho accuracy required tenfold J (b) that tho War Office limit is one-hundredth of an inch, not one-thousandth as'represented; and (c) that tho authorities only nslt for accuracy equal to common or garden locomotive building. I Injvc endeavoured . to avoid; technicalities, hut I feel the abov9 will prove interesting, and. I should liko

to point out that the difficulties of manufacture—if wo are to make shell by the very latest and most approval method—lie not so much in regard to want of suitable lathes, as has been publicly stated, but in regard to a more serious matter, which I pointed out at the meotins of engineers held on July 5, namely, the provision of hydraulic forging presses. In .rcgiird to this, I am pleased to bo ablo to say that I havo recently gone most carefully into the matter of the plant required with one of tho Dominion's most prominent and most experienced engineers, who, moreover, owns ono of the largest engineering works, and ho stated to me that ho is quito prepared to construct the requisite presses. What now do we learn from the foregoing? It is this: (a) That shell can be made in the Dominion, (b) Tliat this can be done with plant and machinery at,present in. New Zealand. (Note — The interim report of the confereya of engineers upon the manufacture of munitions expresses this view upon both these points.) (c) That locally made shell can bo made of accuracy equal to, or if need be, 'surpassing, that of Imperial shell, (d) That the results from tho sample shells already mado locally are gratifying, and surprising, when it is remembered that unlsnown steel of unsuitable quality was made use 6f. I feel that Alio foregoing will serve as & perfectly satisfactory answer to tho question "Can shell be made in the Dominion?" Moreover, it proves conclusively that, given the required mateiv iai, no' difficulty, mil be experienced in helping the Mother Country with such munitions, and of superior quality. The thing which blocks the way and has been allowed for so long to block the way, is want of organisation.—l am, et °'' . ALFD. ,R. SENNETT.