The Giant's Eye: the Optical Munitions Exhibition
http://www.asap.unimelb.edu.au/bsparcs/exhib/omp/

Published by ASAP on ASAPWeb, 30 April 1997
E-Mail: bsparcs@asap.unimelb.edu.au
Prepared by Denise Sutherland and Elissa Tenkate


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Background Information


Australian History Timeline 1939-1946
Optical Glass
Optical Munitions
Some Difficulties


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Optical Glass
http://www.asap.unimelb.edu.au/bsparcs/exhib/omp/bgrnd/glass.htm

Optical glass is used for optical instruments, such as binoculars, spectacles, lenses, prisms, telescopes, and microscopes. It must be absolutely flawless, completely transparent and able to be ground into shape. Of all glass types, it has the widest range of compositions, each having slightly different ingredients and optical properties.

During the Second World War, the Optical Munitions Panel recommended that six types of optical glass should be made in Australia:

* Hard Crown;
* Dense Flint;
* Borosilicate Crown;
* Extra Dense Flint;
* Medium Barium Crown; and
* Telescope Flint.

The production of optical glass requires special ingredients, in particular a high grade, iron-free source of silica (sand). Aeolian sand is considered one of the best types of sand for making optical glass and, fortunately, Australia had a domestic source of this essential ingredient at Botany, in Sydney.

Other ingredients required for optical glass came from various Australian states:

* calcite (for lime or calcium oxide) - George's Plains (near Bathurst, New South Wales);
* zinc oxide - Tasmania;
* lead oxide - Port Pirie, South Australia; and
* soda ash - Imperial Chemical Industries' plant at Osborne, South Australia.

The remaining ingredients were supplied by the UK (potassium nitrate and hydrated alumina) and the USA (borax and boric acid) and had been stockpiled by Australian Consolidated Industries before war broke out. (1)

However, while Australia had all the ingredients to make optical glass, we did not have the procedures in place to do so. Optical glass is hard to form and expensive to produce; extraordinarily high temperatures are required to melt the quartz sands and these temperature make the mixture highly reactive. This can lead to contamination of the mixture through chemical reactions with containers that hold the molten glass. Optical glass is also a very viscous product, and it is difficult to get tiny bubbles out of the mixture.

To make optical glass, fine sand and various mixtures of oxides, such as potash (potassium oxide), soda (sodium oxide), lime (calcium oxide) and magnesium oxide are melted together in a pot. The pot, or refractory, is lined with, or made of, special clays. As mentioned above, the glass produced in the refractory can be affected by impurities in the clay which leak out of the clay and into the 'melt' of optical glass.

Australian Consolidated Industries, in conjuction with Professor Hartung from the University of Melbourne, tested over 100 clays from all over Australia until they found the right clays to use in their pot construction.

In June 1941, Hartung reported: 'Much work has been done on the testing and selection of suitable pot clays for melting optical glass. After the accumulation of sufficient evidence from our experiments in Melbourne, I went to Sydney towards the end of February last, and discussed the whole matter fully with the staff of Messrs. A.C.I. who are concerned with the development of the project. As a result, a standard blend of four pot clays was selected for use in the making of full scale pots for the production of optical glass.' (2)

Following the production of the 'melt', the optical glass is then poured into moulds which form prisms, lens blanks and slabs. Prism cubes of up to 5 inches (12.7 cm) and lenses of up to 8 inches (20.3 cm) were made by an Australian Consolidated Industries subsidiary: Australian Window Glass Pty Ltd, in Sydney.

After moulding, the glass blanks are annealed. Annealing is the process of controlled thermal treatment to lower the level of strain inside the glass caused by uneven cooling. It involves raising the glass to a high enough temperature to relieve the strain, then the glass is gradually cooled again. Optical glass needs the most careful annealing because of the significant effect of residual strain on the final optical properties of the glass.

References
(1) D.P. Mellor (1958), 'Optical Munitions', Australia in the War of 1939-1945: The Role of Science and Industry, ch. 12, series 4: civil, vol. 5, Australian War Memorial, Canberra, p. 255.
(2) J.S. Rogers, The History of the Optical Munitions Panel: July 1940 - December 1946, Australian Archives, Brighton, Melbourne, MP 730/11, Box 3, p. 49.


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Optical Munitions
http://www.asap.unimelb.edu.au/bsparcs/exhib/omp/bgrnd/munitions.htm

'Optical munitions' are optical instruments that are used in war - more specifically, they are optical instruments associated with weapons.

During the Second World War, the Optical Munitions Panel produced the following items:

* angle of sight instruments;
* submarine and tank periscopes;
* elevation and bearing telescopes;
* directors;
* range finders;
* ring sight and signalling telescopes;
* telescopic rifle sights;
* parabolic reflectors;
* stereoscopes;
* sextants;
* camera lenses and prisms;
* spirit and optical levels;
* theodolites;
* collimators;
* lensatic sights;
* auxilliary telescopes;
* glide path indicators;
* jungle sights; and
* reconnaissance and flash spotting instruments.

The Optical Munitions Panel also coordinated the reconditioning of over 17,000 binoculars at various locations around Australia. Reconditioning involved the replacement of lenses with more powerful optics, and many of these binoculars were donated to the war effort by the public. (For difficulties associated with the use of optical instruments in the tropics and how the problems were solved, see the Tropic Proofing Committee.)


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Some Difficulties
http://www.asap.unimelb.edu.au/bsparcs/exhib/omp/bgrnd/problems.htm

Dificulties arose for the Optical Munitions Panel in that they were required to supply a full range of optical munitions, but in small quantities (due to the relatively small requirements of Australia's fighting forces in comparison to British and American forces). The small quantities required by the Australian defence forces restricted the establishment of production lines because, by the time production of a particular item was flowing smoothly, the quota was filled and a new item would be required.

Hartnett writes:

'We had to create virtually the whole range of ordnance requirements, and we had to do everything from scratch. We'd make the dies, adapt the machine-tools, do all the drawings and specifications and start a production process that, by rights, should have gone on turning out goods by the thousand. But no sooner would we have our production flowing than we would fill the requirement, and we'd have to get on to something else. It was terribly frustrating. We'd make 200 of this, 500 of that, 300 of the other and - stop! - just as you'd turn the handle of the sausage machine, someone would call, 'Halt - enough sausages!' (1)

The early stages of optical production at the Commonwealth Solar Observatory (CSO) did not run smoothly. Genuine problems with quality control were encountered, hampered by communication problems between work sections. In early 1943, an Ordnance Production Directorate (OPD) report on the CSO was very critical of the low standard of production work. The report stressed that, unless the various CSO section heads could work harmoniously and the quality of work improved, then the CSO should 'be relieved of all its production work'. (2)

The training of workers and the efficient, clean and consistent operation of the assembly shop were the main areas of concern. Cla Allen was very aware of these issues and, in coordination with Woolley, the CSO Director, was instrumental in getting the CSO operating at the appropriate level. Within a few months, the same OPD official was happy to report an improvement in the situation.

References
(1) Sir Laurence Hartnett (1973), Big Wheels and Little Wheels, 2nd edn, Gold Star Publications, Hawthorn, Victoria, p. 133.
(2) Memo from T.J. Malcolmson to T. Hedberg, 21 January 1943, Australian Archives, MP 392/9, Box 12 - Optical - Machine tools & Mount Stromlo.


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Australian History Timeline
http://www.asap.unimelb.edu.au/bsparcs/exhib/omp/bgrnd/

1939

* 3 September: War was declared on Germany by the Australian Prime Minister Robert Gordon Menzies.
* Forty-four hour working week became standard throughout Australia.
* Press censorship was adopted.
* Bushfires in Victoria killed seventy-one people.
* Conscription for home service was established.
* The first meeting between physicists and the Menzies Government was held.
* CSIR/O began secret radar research at the University of Sydney.
* Short-wave radio service Australia Calling (later renamed Radio Australia) began broadcasts from Sydney in English, Spanish, French and Dutch.

1940

* Over 2,000 German 'aliens' arrived from the United Kingdom on the ship Dunera.
* Communist and Fascist parties were banned.
* Australian servicemen and women saw action in North Africa and the Middle East.
* Volunteer Defence Corps were established.
* Bass Strait was closed to shipping following the sinking of a British ship (the result of enemy mines).
* Petrol rationing began.
* The Optical Munitions Panel was established in July.
* The first optical glass was produced in Australia in December.

1941

* Robert Gordon Menzies resigned as Prime Minister of Australia.
* The Australian Labor Party took office, led by John Curtin.
* Australian defence forces were engaged in action around the Mediterranean (primarily in North Africa, Greece, Syria and Crete).
* Sydney opthalmologist Norman Gregg discovered the connection between birth defects and the Rubella virus in pregnancy.
* Child endowment was introduced by Commonwealth Government.
* Australia declared war on Japan on 8 December.
* HMAS Sydney was sunk by the German auxiliary cruiser Kormoran off the Western Australian coast. All hands were lost (645 men).
* Australian balladist 'Banjo' Patterson died. His writings include The Man from Snowy River and Waltzing Matilda.
* The film Forty Thousand Horsemen was produced on sand dunes at Coogee (in Sydney, New South Wales) by Australian actor, writer and director Charles Chauvel.
* 7 December 1941: Japan launched her Pacific campaign by attacking Pearl Harbour, Hawaii, USA.

1942

* John James McNeill returned to the Munitions Supply Laboratories after a fruitful period of study in England.
* Over 15,000 Australian soldiers were imprisoned by Japanese following the fall of Singapore on 15 February.
* 243 people died when Darwin was bombed by the Japanese on 19 February.
* The Battle of El Alamein, North Africa.
* The Battle of the Coral Sea.
* The Battle of the Kokoda Trail, New Guinea.
* Broome and Wyndham, in northern Western Australia, were bombed by the Japanese.
* Three midget Japanese submarines entered Sydney Harbour.
* Allied headquarters were established in Australia under the leadership of General Douglas MacArthur of the USA.
* State income tax was abolished when the Commonwealth Government took over the administration of income tax.
* The Communist Party in Australia was legalised.
* Clothes, tea and sugar rationing began.
* Daylight saving was first introduced.

1943

* Conscription was introduced for overseas military service.
* Darwin encountered its last bombing raids (conducted by the Japanese).
* Japanese bombing occurred off the coast of Exmouth, Western Australia.
* Cooking appliances and butter rationing began.
* Australia became the first country in the world to make penicillin available
to civilians: see Howard Walter Florey.
* Pay-As-You-Earn (PAYE) income tax was introduced by the Commonwealth Government.
* Letters were sent on microfilm from Australia to the United Kingdom.
* The first Australian women were elected to Federal Parliament.
* William Dobell was controversially awarded the Archibald Prize,
for his painting Joshua Smith.

1944

* Meat rationing began.
* Japanese prisoners-of-war escaped from their internee camp at Cowra, New South Wales: 234 prisoners and 4 guards were killed.
* The Liberal Party was formed by Robert Gordon Menzies out of the remnants of the former United Australia Party.
* Australia and New Zealand signed the ANZAC pact.
* Commonwealth unemployment and sickness benefits were first introduced.
* Bushfires in Victoria killed fifty-one people.
* T.H. Laby resigned as Chairman of the Optical Munitions Panel.

1945

* John Curtin died while Prime Minister of Australia. Ben Chifley took his place as Prime Minister.
* The atomic bomb was dropped on Hiroshima, Japan, on 6 August, and another on Nagasaki on 9 August.
* 15 August: The Second World War ended in the Pacific region with the surrender of Japan. (The war in Europe had ended previously, when Germany surrendered on 7 May.)
* Australia became a member of the United Nations.
* Howard Walter Florey became the first Australian to win the Nobel Prize (for his work on penicillin).
* Two million sheep died in a wide-spread drought.
* The National Film Board was established.
* Alcoholics Anonymous was established in Australia.
* The first Sydney-Hobart yacht race was held.
* The Optical Munitions Panel held their final meeting.

1946

* A massive migration program (to Australia) for people from Britain and Europe began.
* Trans-Australian Airways (TAA) was established.
* Australia and Britain entered a joint venture for the testing of weapons with the establishment of the Woomera rocket range in South Australia.
* N.J.O. Makin becomes the first president of the United Nations Security
Council.
* The Australian National University was established.
* The Sydney Symphony Orchestra was established as a full-time body.
* Professor T.H. Laby died.


Source: The Concise Australian Reference Book, Golden Press in association with Daniel O'Keefe Publishing, Drummoyne, NSW, 1986.


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