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THIS DOCUMENT IS THE PROPERTY OF HIS BRITANNIC MAJESTY'S GOVERNMENT

TO BE KEPT UNDER LOCK AND KEY.

It is requested that special care may be taken to ensure the secrecy of this document.

CL

159

COPY NO. 30

CRET.

.S.(40) 244.

WAR CABINET.

CHIEFS OF STAFF COMMITTEE.

A.Á. AMMUNITION EXPENDITURE.

MEMORANDUM BY THE CHIEF OF THE IMPERIAL GENERAL STAFF.

Requirements in A.A. Ammunition, based on the accepted rates of expenditure and the present programmes of guns, amount by Z 24 to about twenty two million rounds of Heavy and twenty four million rounds of Light A.A. Ammunition. Furthermore, the estimated monthly wastage after Z + 24 is about one million rounds Heavy, and two million rounds Light A.A.

2. The War Office have re-examined these figures with the results that their present proposals amount to about half the above figures for total expenditure and an even greater reduction in monthly wastage after Z + 24.

3.

The detailed arguments, which lead to this conclusion, are attached as Appendix A. These may be briefly summarised as follows:-

(i) The scales of ammunition for A.D.G.B., as agreed to by the

C.I.D. prior to the war were based on the building of six months' supply, on the hypothesis that new production would

This is no not materialize until the end of that period. longer the case.

(ii)

(iii)

In arriving at their conclusions with regard to A.D.G.B., it was assumed that the bulk of the enemy air effort would be directed against Great Britain. This may be so, but an air effort on this scale against Great Britain (the figures assumed were an average of about 2,000 raids per week, over the period of six months, of which 1,300 were assumed to have been engaged by A.A. guns) must imply a corresponding diminution of effort on the continent and vice versa.

The accepted scale of expenditure for guns with the B.E.F. has been taken as 30 R.P.G. per day.

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The expenditure in France in 1918, corresponding to an average of 1,000 targets per week was out 11 R.P.G. per day.

Although the range of AA. guns has increased, the rate of fire as compared with 1918 has been reduced by about 33%. more modern aircraft fly about three times as fast. implies that a given target will be under fire for a shorter period and during that period fewer rounds will be fired.

Further- This

For the above reasons an expenditure of 30 R.P.G. per day for guns in the B.E.F. is considered excessive.

4.

(iv)

Finally, the strength and efficiency of our present day fight -

With modern methods of organization here on the problem.

interception out of a given number of raids fewer will be targets for the guns.

The above considerations led to the conclusions that a lessen vorall provision of ammunition was acceptable. In arriving at what this lesser provision should be, two main factors were taken into account:-

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(i)

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