CAB80-25 — Page 41

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Scope of Smoke Protection Measures.

3.

The problem of producing smoke screens was defined by the Smoke Committee as the production of haze sufficiently dense to obscure targets on moonlight nights and of sufficient extent to make aimed bombing of targets impossible. This is a different problem from that ordinarily considered under the heading of smoke screens, which normally consist of heavy palls of smoke for obscuration in daylight. So far as is known screens at night have never before been seriously considered.

4.

Following intensive experimental work the practical methods of achieving this end were reduced to five

(a) increased general industrial haze from existing

factory chimneys - by waiving smoke abatement regulations in industrial areas;

(b) special apparatus for thickening general industrial

haze installed in industrial establishments;

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(c) burning smoke-producing material in domestic grates;

(d) small oil burning generators - for producing smoke

haze over an appreciable area surrounding a vital factory.

(e) large (Haslar) mobile oil burning generators - as

for (a).

5.

It was decided that of these five methods it was practicable to adopt only (a) increased industrial haze and (a) and (e) oil burning generators (small and large) for immediate use. Development work was put in hand on the remaining two methods ((b) and (c) above).

6.

III.

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PROGRESS UP TO THE END OF DECEMBER, 1940, AND PRESENT POSITION.

An account of the work which has been performed up to the end of December is given in Appendix B under the following heads:-

Oil-burning generator schemes

Industrial haze

Household grates

The present position is summarised in the following paragraphs.

•

7.

Oil burning generator schemes.

Operations at vital targets

w

Smoke protection

schemes have been operated over the vital targets listed in Appendix D during the July, September, October, November and December moonlight periods. This has involved the use of approximately 100,000 generators;-the employment of about 4,000 troops as operating personnel; and the consumption of 18,000 tons of diesel oil.

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