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Defence - Fremantle, Fixed Defences of - Report by Lieut.-Cols. Owen, Bridges, and Le Mesurier on Statements made by Senator Matheson as to Armament


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THE PARLIAMENT OF THE COMMONWEALTH OF AUSTRALIA.

FIXED DEFEXCES OF FREMAXTLE,

(REPORT BY LIEUT.-COLS. OWEN, BRIDGES, AND LE M ESURIER

ON STATEMENTS MADE BY SENATOR MATHESON AS TO ARMAMENT.)

Presented by Command; ordered by the Senate to he printed, 12th October, 1905.

[Co,si o f P aper.—Preparation not given ; 900 copies ; approxim ate cost of printing and publishing, £2 5s.].

No. 1905/9221.

M IN U TE PAPER.

Subject:— Mounting of Guns at North Fremantle, Western Australia.

In consequence of the question raised in the Senate on the 15th instant, as to the utility of the 7.5-inch guns, proposed to be placed at North F remantle, Western Australia, I desire that the officers who recommended these guns in their report of the 27th March, 1905 (Lt.-Cols. Bridges, Owen, and Le Mesurier), should traverse the statements made by Senator Matheson, and furnish me with their remarks at an early date.

(Sgd.) T. P.LAYFORD,

Minister of State for Defence.

20.9.05.

N o t e s b y L i e u t e n a n t - C o l o n e l O w e n o n t h e

S t a t e m e n t s m a d e b y S e n a t o r M a t h e s o n o n

1 5 T H S e p t e m b e r , 1 9 0 5 . i n t h e S e n a t e , r e g a r d ­

i n g t h e P r o p o s e d A r m a m e n t f o r t h e F i x e d

D e f e n c e s o f F r e m a n t l e .

(t) The arguments raised by Senator Matheson resolve into a contention that if 7.5-inch guns are mounted a certain proportion of the vessels likely to attack could effect their objective, without com­

ing within the effective range of the shore guns. (2) The objective stated bv Senator Matheson is a quotation from the Colonial Defence Committee’s remarks: —

“ The object of fixed defences at Fremantle is to deter not more than four cruisers from lying outside the Breakwater, and destroy­ ing the wharfs and shipping by gun

fire.”

(3) In a later part of the speech, Senator Mathe­ son states that those vessels would not only be able to bombard the port, but “ would be able to silence our 7.5-inch guns with a shot or two.”

N O . 3 9 , — E U 0 4 3 1 .

(4) Senator Matheson also quotes the Colonial Defence Committee that some of the attacking vessels might be armoured, but, later in his speech, asks whether the y ^ in c h guns are “ capable of

piercing the armour of armoured ships which are- likely to lie off the harbor of Fremantle.” (5) In commenting on the contentions raised, I think it best to divide the factors involved as fol­

lows :—· (a) Vessels likely to attack. (b) Objective, and how it would be at­

tempted.

(c) Requirements of defence. (d) Relative attributes of respective ord­ nance.

Vessels likely to Attack.

(a) With regard to (a) the Colonial Defence Committee have, in another report, stated that the vessels likely to attack in Australian waters would be of the lightly-armoured class, having in view that

the presence of the heavilv-armoured vessels would be required elsewhere. The fact is not alluded to, but it is patent that in the event of a serious

embarrassment, during which more heavily-armoured and superior vessels could be spared, there are more important objectives for the enemy—and that the enemy would not be likely to disclose himself and

risk impairing the mobility of his vessels (by an in­ jury to one or more) before attempting to accomplish that more important objective. It can be assumed that vessels likely to attack Fremantle would be lightly armoured cruisers.

Objective, and how it would be Attempted.

(b) The objective has been stated, namely, to· attack the shipping and wharfs, but the way in which it would be attempted to achieve that objec­ tive has not been stated. It may be assumed that vessels would not engage in an attack unless they

could see the effect of their fire; it is unlikely that, vessels would expend ammunition without some

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knowledge of the result. The only view of the

shipping and the wharfs is between two moles, and the area is bounded by two lines radiating from the harbor, and about seven cables a p a rt. at the place where the vessels could attack.

Taking into consideration the position of shoal water, and assuming that vessels must circle or perform an evolution, and that four vessels would be engaged, they would necessarily, in the course

of their evolution, come closer than 5,500 yards to the proposed North Fremantle fort, and at that range present broadside (at the turn). They would, at the same time, come within effective range of the 6-inch B.L. Mk. V II. guns, and a slow speed would be precluded.

I f there were an accurate and rapid fire from the shore guns, it is very doubtful whether vessels would, for a comparatively small gain (the objec­ tive), take the involved risks, and the effect of the fixed defences would be to deny the water from which the port could be attacked, which, in other

words, is the object of fixed defences stated by the Colonial Defence Committee, vide paragraph 2. The General Officer Commanding, when on the spot, was fully cognisant, and went over the water in a

steam launch. Senator Matheson's suggestion that the attack could silence our guns “ with a shot or tw o” is

manifestly untenable, and it is doubtful whether an attack on coast defences of modern design, offering, as they do, a very small target, will be successful, unless x-essels can close up to a short range, at which their fire will be accurate, and the preponderance of armament thus rendered effective

(supported by a land attack).

Requirements of Defence.

(c) One of the prime considerations in selecting armament was rapiditv of fire, for the following reasons : —· It is not possible to mount, in. effective positions,

more than four guns to cover the area referred to in (b), and further that rapidity of fire would

assist ranging from such low sites, i.e., considering the margin of error of the automatic sights on such a low site, the advantage of rapid fire is of importance for ranging, apart from the increased weight of metal thereby attained.

Relative Attributes of Respective Ordnance.

(d) I am not in a position to make any compari­ son regarding the ballistics of the respective guns, but Senator Matheson’s conclusions are based on the greater perforation of the 9.2-inch B.L. gun

compared with the 7.5-inch gun at 6,000 yards. I have stated reasons against his assumption regard­ ing the class of vessel, and shown that in the attack vessels must necessarily come within a lesser range

than that mentioned by him. In choosing arma­ ment, all factors must be considered ; the import­ ance of rapiditv of fire has been alluded to, and in that respect the 7.5-inch gun has the advantage.

The mechanism necessary for sendee of the 9.2-inch gun ammunition is a disadvantage. H y­ draulic or electric machinery, for handling the projectiles of heavy ordnance, is an unavoidable -contingency, but complicated machinery is a factor

to be avoided if possible. In this respect the

7.5-inch gun holds out an advantage. In addi­ tion to the possibility of mechanism going out of order at a critical time, there is the necessity for skilled mechanics to maintain it at all times in

working order, and an additional responsibility and expense for maintenance and the trained per­ sonnel.

With regard to cost, there is apparently much to be done in other parts of the Commonwealth, and that question of policy I cannot comment pn, but realizing the necessities elsewhere, it would have been culpable to select a more costly armament than was required to fulfil the requirements of the

defence.

(Sgd.) PERCY T. OW EN.

No. 128G.

Commonwealth of Australia, Department of Defence, Melbourne, 29th September, 1905. Minister of Defence.

1. In compliance with your instructions, con­ tained in the memorandum of the Acting Secretary of Defence, dated 16th instant, that I should report upon Senator Matheson’s remarks respecting the Fremantle defences, and the instructions in your minute of the 20th instant, to traverse the state­ ments made by Senator Matheson, I beg to sub­ mit the following remarks :—

2. It appears, from Hansard reports of the pro­ ceedings of the Senate, that some misapprehension exists as to the views of the late General Officer Commanding, respecting the defences of Fremantle,

and as the report states you consider that blame rests with those advisers of the late Minister, xvho recommended the purchase of the 7.5-inch B.L. guns, it seems desirable, before dealing with Senator

Matheson’s criticisms, to shortly state the pro­ posals which have been made respecting the de­ fences of Fremantle. After visiting Western Australia, the late General Officer Commanding recommended on the 5th June,

1903, that— “ In view of the great and increasing develop­ ment of the port of Fremantle, Western Australia, the defence of that place should

be included in the fortified harbors of the Commonwealth, and that the necessary steps should be taken m the forthcoming Estimates for the necessary sum of money to be allotted.” He desired, for economical reasons, to make use of the spare guns then in the Commonwealth, and accordingly recommended that the spare 9.2-inch

B.L. Mark VI. gun in Sydney should be mounted in Fort Forrest, and a second gun obtained later on; that one 6-inch B.L. Mark VII. gun, then in Adelaide, should be mounted at Arthur’s Head,

and a second gun provided for that fort later on. As some difficulty was experienced in deciding the best pattern of mounting for the 9.2-inch B.L., the question was referred to the Home authorities in the Governor-General’s despatch, dated 18th June,

1903. The above proposals were referred to the Colonial Defence Committee, xvho discussed the question of the defences for Fremantle in a report dated 25th

November, 1903. In paragraph 10 o f this report, the Committee supplied alternative estimates of cost for—-(a) Two 7.5-inch and two 6-inch guns; and

(b) Four 7.5-inch guns. Commenting on this report, the late General Offi­ cer Commanding stated, on the 26th August, 1904, that “ the scheme contained in paragraph 10 is at once the most effective and the cheapest.” He did not, however, include the amount—

“ in the Estimates of xvarlike stores submitted by me up to/ the present date. I have con­ sidered it advisable not to recommend

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any further expenditure in regard to the fixed defences required, to complete the defences of Fremantle until the Field Force and the Garrison Troops of the .Commonwealth have been armed and

equipped in a reasonably effective man­ ner.” Upon receiving a copy of a minute from the Minis­ ter of Defence to the Treasurer, dated 23rd Sep­ tember, 1904, in which it was proposed to pur­ chase four 7.5-inch B.L. guns, the General Officer

Commanding pointed out that it was not clear from the wording of the Colonial Defence Committee’s memorandum that they considered four 7.5-inch guns the best solution of the question. He recom­

mended that two 7.5-inch B.L. guns and two 6-inch B.L., Mark V II., should be obtained in place of four 7.5-inch, because the site at Arthur’s Head was too restricted to mount two 7.5-inch guns, and

also stated—· “ In view of other and far more pressing de­ mands for armament and equipment for the defence of the Commonwealth, I can­

not see sufficient reasons for justifying the outlay of public money on armament which, in my military judgment, is un­ necessary at the present moment.”

The Minister approved of the General Officer Com­ manding’s suggestion, and informed the Treasury to that effect on'the n t h October, 1904.

On the. 16th March, 1905, the District Com­ mandant, Western Australia, suggested that one 9.2-inch B.L. and one Q .F. of a smaller calibre should be substituted for two 7.5-inch B.L., and on

the 23rd of the same month the Inspector-General ‘ suggested that before the 6-inch B.L. and 7.5-inch B.L. are mounted, “further consideration should be given to the question of whether heavier armament

should not be chosen for these defences.” These suggestions were referred to the Chief of Intelli­ gence, the Inspector-General of Public Works, and the Chief of Ordnance, who reported that thev

saw no reason for changing the conclusions which had been arrived at bv the late General Officer Commanding and the 'Colonial Defence Committee. From the foregoing statements it will be seen,

first, that the proposal to mount 7.5-inch guns at Fremantle emanated from the Colonial Defence Committee, and, secondly, that the late General Officer Commanding was in favour of Fremantle

being defended. It may be added that instead of Major-General Sir Edward Hutton being of opinion that Sydney was the only place in Australia that should be defended, he was at issue with the

Colonial Defence Committee, who desired to re­ strict the fortified ports of Western Australia to Fremantle, he being of opinion that both Fremantle and Albany should be fortified.

3. The following extracts from Senator Mathe- son’s speech are taken from the Hansard reports— Referring to the 7.5-mch guns, he states— “ For our purposes they are, as I sav,

absolutely useless” (p. 2348). “ It is an absolute waste of money to spend one single penny on the fortifications of either Fremantle, Sydney, or Melbourne, unless

guns of a higher calibre than 7.5-inch are to be employed” (p. 2356). “ The idea is to have heavy ordnance, capable of penetrating armour at a distance of

6,000 yards” (p. 2356). “ I maintain that, if we make any purchase at all, we ought to purchase new 9.2 guns for all our fo rts” (p. 2356).

“ The penetrative power of the 9.2 .gun is

7.8 inches of K rupp’s steel at 6,000

yards” (p. 2356). _

“ At 6,000 yards the penetrative power of the 9.2 gun is 7.8, and that of the 7.5-inch

gun is only 5^ inches ” (p. 2358).

From these quotations it would appear that, in Senator Matheson’s opinion, a gun is useless that cannot perforate more than 5! inches of K rupp’s steel at 6,000 yards;· this, according to him,. is the

limit of. perforation of the 7.5-inch B.L., which, consequently, is useless. The 9.2-inch B.L., Mark X, according to him, can penetrate 7.8 inches at 6,000 yards, and is a useful gun.

The statement that the 9.2-inch B.L. will pene­ trate 7.8 inches of K rupp’s steel will be shown later on to be founded upon a misapprehension.

The following considerations show that the as­ sumption that the thickness of armour that can be perforated by a shot from a given gun, as laid down in tables of perforation, will be realized in action

is unwarranted, and, further, that the tables them­ selves are by no means infallible.

Tables of perforation are based on the assump­ tion that the shot strikes normally, a condition that can only occur in exceptional instances in an engage­ ment between ships and forts. Shots glance that

make an angle greater than 35 degrees with the normal. To ensure a shot which makes a smaller angle than 35 degrees with the normal perforating a 6-inch plate, it must be capable, when it strikes normally, of perforating a plate 7.7 inches thick.

Moreover, in the application of perforation for­ mulae to Krupp’s steel, it is found that the several formulae give results differing more· or less widely,

and no formula has been found to agree with ex­ periments for all thicknesses of armour plate and all striking velocities; for instance, K rupp’s for­ mula for the perforation of K rupp’s steel by un­ capped service armour-piercing projectiles gives the

perforation of a 9.2-inch shot, with a striking velo­ city of*2,7oo f.s., as 11.6 inches, whereas Tresid- der’s formula gives it as 14.9 inches. The recent trials of the armour for the Japanese battleship

No. 1 furnish an illustration of a different kind. Two shots made to the English Government stan­ dard pattern were fired from a 9.2-inch B.L. with

a striking velocity of 1817 and 1766 f.s. at a

sample 8|-inch plate; they failed to perforate the plate, in which no cracks were developed; on this result the plate was accepted. A third round was then fired at a higher velocity of 1955 f.s., which

also failed to perforate the plate or cause cracks in it. Subsequently, a fourth round was fired with a new type of uncapped shot, made bv another

maker, with a striking velocity of 1966 f.s.---prac­ tically the same as the velocity of the third round— which completely perforated the plate and passed through a screen of sandbags 10 feet thick. It

was recovered with fhe head broken off, and showed no sign of setting up.

Senator Matheson is, apparentlv, mistaken in stating that the Colonial Defence Committee have stated that the 9.2-inch B.L., Mark X, is capable of perforating 7.8 inches of K rupp’s steel at 6,000 yards. The Colonial Defence Committee, in a report dated gth March, 1904, stated, with refer­

ence to the 9.2-inch B.L., Mark X, that the “ pene­ tration into steel (value 2) at 6,000 yards” is 7.8 inches. Reference to the 9.2-inch B.L., Mark X,

range table shows that the armour referred to by the Colonial Defence Committee is Harveyed arm­ our and not Kruppized steel. Brassev, to whom Senator Matheson appeals as an authority, states

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that the resistance to perforation by uncapped pro­ jectiles of 5f inches of K rupp’s steel is equivalent to 7! inches of Harvey’s steel. (It is also officially stated that a 9.2-inch armour-piercing shell, at a range of 3,000 yards, striking at 30 degrees to the normal, may be expected to perforate about 7 inches of Harveyed steel.) It will thus be seen that a

shot from the 9'.2-inch B.L., Mark X, cannot per­ forate a Harvey plate thicker than the perforation Senator Matheson lays down for a 7.5-inch shot. The conclusion to be drawn is that, if the condi­ tions laid down by Senator Matheson, viz., per­ foration of 6 inches of Kruppized steel at 6,000 yards, are to be satisfied, guns of larger calibre than 9.2-inch B.L. must be provided.

I do not, however, concur with Senator Mathe­ son in considering that guns mounted at Fremantle should necessarily be capable of perforating 6 inches of Kruppized steel at 6,000 yards, nor do I consi­

der the 7.5-inch B.L. a useless gun. The object of mounting guns at Fremantle is to deny to an enemy the area of water from which an enemy could destroy shipping lying in the harbor; for this pur­ pose it is not necessary to have guns capable of piercing a 6-inch armoured belt. In the very re­ port to which Senator Matheson has referred, the Colonial Defence Committee, after comparing the comparative ballistic properties of the 6-inch Mark IV., 6-inch B.L. converted, 7.5-inch and 9.2-inch B.L., Mark X, state that while recognising that the—

“ 6-inch B.L. would inflict but little damage, except at the shortest ranges, upon arm­ oured cruisers of the more completely pro­ tected class—which, however, are little

likely to be met with in Australian waters — (they) are of opinion that this armament would be reasonably sufficient to deter an enemy from attacking.”

The 6-inch B.L. gun the Committee refer to can only penetrate 3 inches of Harveyized steel at 6,000 yards.

I f the guns are sufficiently powerful to deter an enemy from attacking, the purpose for which they are provided will be attained. The probable at­ tacking force is laid down by the Colonial Defence

Committee as “ four hostile cruisers, some of which might be armoured.” The 7.5-inch is sufficiently powerful to deal with unarmoured cruisers and the unarmoured and lightly armoured parts of arm­ oured cruisers. Considering, therefore, both the

possible gain and the risks to such a squadron attacking Fremantle, it appears that the 7.5-inch B.L. is a sufficiently powerful gun to deter an

attack.

Compared with the 9.2-inch B.L., Mark X, the 7.5-inch B.L. has the following advantages— The gun and mounting cost about ^ 6 ,0 0 0 less than the 9.2.

The cost of the ammunition is much less, and. if the money available for practice am­ munition is limited, a larger number of rounds are available for practice pur­ poses. The probable life of the rifling of the 9.2-inch,

Mark X, is 125 full rounds; the life of the rifling of the 7.5-inch is not laid down, but since that of the 8-inch is 350 rounds, and of the 6-inch, Mark X, 350, it seems, reasonable to assume that the life of the rifling of the 7.5-inch is at least twice

that of the 9.2. The mounting of the 7.5-inch is simpler, easier to work, and cheaper to maintain in

order.

The rate of fire is greater, and it requires a

smaller detachment, and consequently the annual cost of the garrison is less. To recapitulate: I f the strength of the Fremantle defences is to be fixed by the probable strength of the enemy, and not upon an extreme possibility, and if the strength mentioned by the Colonial De­ fence Committee is a reasonable estimate of a hostile force, then it appears that the 7.5-inch is not only a sufficiently powerful gun, but it possesses other advantages than that of cheapness over the 9.2-inch B .L., Mark X. Indeed, until the sum spent in

the instruction of the forces is increased, it does not seem possible to justify an expenditure of .

j£i2,ooo in order to secure an additional theoretical penetration of armour of two inches. On the

other hand, if the conditions demanded by Senator Matheson are to be satisfied, viz., penetration o f 6 inches of Kruppized steel at 6,000 yards, then a

more powerful gun than the 9.2 should be obtained. 4. In the Hansard report there are references to a local Intelligence Department. I may, there­ fore, take this opportunity to point out that there is no Intelligence Department in the Military Forces of Australia in the sense in which that term is

understood in the Imperial Service and in Canada, unless a single officer constitutes a department, and this minute is sufficient to show that he is not em­ ployed upon intelligence work.

_ (Signed) W. T. BRIDGES,

Lieut.-Colonel, R.A.A., Chief of Intelligence.

I desire to inform the Minister of Defence that I entirely concur with the views expressed and the deductions drawn by Lieut.-Colonel Bridges, R.A.A. (Chief of Intelligence), in his memorandum to the Minister, dated 29th September, 1905,. respecting the Fremantle defences.

(Signed)_ H. LE M ESURIER,

Lieut.-Colonel, Chief of Ordnance. Secretary. Melbourne, 6/10/05.

P rin ted and Published for the Government of the Commonwealth of Australia b y R obt. S. B rain, Government Printer for the State of Victoria.