Helping the War Effort

During World War II, the quarry, like so many other industries suffered from a shortage of labour and as a result it crushed rock production fell from 20,199 tons in 1940 to 16,399 in 1943.

In a letter to the Lilydale Express in 1944 the manager D.B. Doyle highlighted the use of lime:

“Your readers may be interested to know that lime is practically a munition of war. It is used by all factories making explosives, and it would not have been possible for foundries engaged in heavy munition production to have functioned with the use of our Lilydale products. In addition to this the production of leather for military clothing has called for increasing quantities of lime.“

• Crushed rock shortage

After the war, more and more people were migrating to Australia looking for a new life. Many decided to settle in the Lilydale area and this created issues of a different kind for Cave Hill.

The demand for products increased as did the need for blasting to reach the new seams and soon people were complaining and the shire council became involved:

“Cr McCracken said people would not build brick homes whilst excessive blasting was allowed to continue. They could not be expected to spend £3,000 on a brick home and have it shaken to pieces. The council should bring in a by-law to control the nuisance, seeing that previous requests to modify blasting has been ignored. Instead of modifying the charges, they have greatly increased them.”
(Lilydale Express April 28, 1950.)

In reply manager Doyle said the new methods used resulted in more noise but a great reduction in vibration. His letter provides fascinating insight into the blasting method used and again demonstrated the quarryâ%u20AC%u2122s willingness to be the first to try something different.

• The Great Blasting Debate

Operations through the century

Throughout the years, journalists have re-visited Cave Hill and written about the quarry, its operations, people and business.

Click below to see Cave Hill features 1960 to 1994:

• Cave Hill in 1960
• Cave Hill development 1965
• Cave Hill in 1983
• Cave Hill 1991

A Century of Limestone

The company’s centenary booklet published in 1978 carries interesting photos and potted history about the company:

Since 1878 considerable change has taken place in the calcining of limestone. In the early days stone was burnt in wood-fired kilns, a battery of which still stands (photograph no. 2).

In February, 1936 an automatic vertical shaft mixed feed kiln was installed replacing old pot kilns. This unit was coke-fired and was withdrawn from production in 1964 when two 50 tonne per day oil-fired vertical shaft “West’s” kilns were installed. A third was to follow in 1967. All three kilns (photograph no. 4) were converted from oil to natural gas firing in January, 1976 following the international oil crisis which brought about substantial fuel price rises.

In 1969 the hydration process (the manufacture of “Limil”), was changed from a batch system to a “Knibbs” continuous process. Storage capacity has been expanded and today, provision for some 1,500 tonnes of bulk and bagged lime products exists.

The years have also seen many changes to the method of transporting stone from the quarry face to the primary crushing station. Originally, a tramway system (photograph no. 1) of hauling stone from the face to a skip for elevation to the crusher house (24″ x 15″ crusher) was used. This system was replaced in 1945 with a dumpster bucket system with steel boxes being filled by hand and hauled by a dumpster truck to the skipway.

In 1963 improvements to the quarrying and crushing operation were made with the installation of a new primary crushing system (W’ x 24″ crusher) on the western face. The crusher house, skipway and dumpster trucks then became redundant and 7 c. yd. tipper trucks were used to haul the stone to the new crusher.

Modernization of plant in the quarry continued in 1970. The electric shovels used for loading limestone from the quarry face were replaced with a “Caterpillar” 988 wheeled loader to allow for greater mobility and the 7 c. yd. hauling vehicles were exchanged for 17 tonne “Terex” tippers.

Again, in January, 1977 major changes to the system were made (photograph no. 3) when the crushing station was moved from the western face and relocated close to the top of the quarry with a much larger primary crusher (42″ x 30′) fed by an apron feeder being installed. The winning of low magnesia stone from the western face has been made possible by this action and the larger crusher has provided the means of reducing secondary stone breaking and increasing productivity from a number of sections of the process line.

(Source: Over 100 years of Lime Manufacture, 1978 published by David Mitchell Estate Limited.)

Planning for the New Millenium

In 1991, the company applied to the Shire of Lillydale for a variation of its extractive industry licence to quarry rock in its southern buffer zone area. The information, in support of its town planning application is detailed and explains the company’s past, present and future plans to continue operations until at leat 2020.

Extracts from Cave Hill`s town planning application to the Shire of Lillydale.

New Owners

After more than 124 years ownership, in 2002 the Mitchell family sold the company to Unimin Australia Limited, a diversified industrial mineral producer and supplier, While the family connection may have been severed, the company is still a vital part of the district’s economy and its products continue to be a vital part of the manufacturing, mining and agricultural industries throughout Australia.

Go to http://www.unimin.com.au/

David Mitchell’s Life Story: