Australian
Screen

Teacher’s notes

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This silent black-and-white clip from an industrial documentary made in the 1920s shows work in a limestone quarry at Portland, New South Wales. The clip focuses on a mobile steam shovel lifting large limestone blocks and rubble from the quarry face to carts on rail lines. A long-distance shot of the quarry face conveys the huge size of the machine by contrasting it with men working alongside and walking in front of it. An intertitle explains that the limestone was once the ocean floor. Fossilised shark’s teeth and seashells are shown at the end.

Educational value points

• The clip shows some of the significant advances in quarrying made possible by technological developments after the First World War (1914–18). The steam shovels seen here could manoeuvre through a 360-degree swing, allowing faster excavation than the partial-swing steam shovels that had been in use before the War. Dynamite broke up the limestone and steam shovels such as the one shown loaded the mobile rail bins.

• The mechanised shovel shown here was powered by a steam boiler and ran on caterpillar tracks, an invention of the decade before the First World War that allowed for a high degree of flexibility. Two men operated the shovel. A driver–operator sat on the left, controlling the bucket by means of a lever, and a fireman (not shown in this clip) was responsible for keeping the boiler stoked.

• Steam shovels completed in minutes what teams of men had previously taken hours to do, and therefore their use meant that fewer workers were needed. While such innovations improve productivity and reduce the need for backbreaking labour, they can also cause unemployment and social dislocation when workers and their families are forced to leave a community to find work elsewhere.

• The filming in the clip is carefully staged to highlight the efficiency, scale and capability of the steam shovel. Close-ups show the machine filling a bin with one bucketload. Medium shots show the excavation capacity of the shovel, illustrated by the shovel lifting a limestone boulder the size of a small car. A long shot emphasises the size of the machine as it dwarfs the men alongside it.

• The limestone being quarried in this clip for the manufacture of concrete is a sedimentary rock composed in the main from calcium carbonate. It is usually formed when marine or freshwater fossil debris from fishbones, teeth and shells accumulate and solidify on an ocean floor or riverbed. As the intertitle mentions, the marine fossils found in the quarry are evidence that it was a former seabed. There are significant deposits of limestone throughout Australia.

• The type of cement made from the limestone shown requires high-quality crushed limestone to be mixed with clay and water. The resulting slurry is subjected to further manufacturing processes before it becomes cement powder. The method was originally developed in England in 1824 and the product called Portland cement due to an apparent resemblance to Portland stone.