Swan Portland No. 1 Dredge

Statement of Significance

• The structure has some aesthetic value as a decayed ruin on the foreshore which are evocative of the former industrial practices on the river. • The structure has historic value for its association with the first half of the 20th century when the river was used for transport for commercial practices. • The structure has historic value for its association with the Swan Portland Cement Company who were significant employers in the district. • The structure has historic value for its demonstration of past practices of dredging and the use of oyster shell for the production of lime. • The structure has value for the local community as evidence by the decision to erect as plaque at the site in 1996 in recognition of its significance to the history of the Belmont community.

Physical Description

The wooded remnants of this dredge are exposed in low tide revealing a timber framework in poor condition. The structure is located approximated 50 metres upstream from what was previously known as the Goodwood Parade boatramp and is now the Balbuk Way boatramp alongside the shoreline and a build up of sand has created access to the structure. A survey of the structure in 2004 by the Maritime Archaeology Association of Western Australia designated the dimensions of the structure as 19 metres by 7.2 metres with a draft of 1 metre.

History

The establishment of the West Australian Portland Cement Limited's factory in Rivervale in 1920 made a significant impact on the development of the Belmont District. The company's locally manufactured lime, although cheaper, was initially rejected by the local construction industry but the use of the locally found oyster shell dredged from the Swan River bed was welcomed as it produced a quality product. The company was a significant employer in the district although the environmental impact of its processes were suffered by all who lived nearby. The deposits of decayed oyster shell were found in abundance in the river bed although some areas, such as near the Ascot Racecourse, shell could be found to a depth of 32 feet. Between 1927 and 1956 over 3 million tons of shell was extracted from the river but this source of lime was ultimately unsustainable because of increasing costs. This structure is the remains of one of the dredges which mined the shell from the river bed and loaded barges for transport to the factory. Research by the Maritime Archeology Association of Western Australia has stated that this wreck was known as the Swan Portland No. 1 Dredge. A former worker at Swan Portland Cement Company, Charlie Klegg, described the process as follows: The dredge was built of timber and the drag line was powered by a coal burning steam engine. The method of holding these dredges in position was by using two 11/2 ton anchors off the bow with a 600′ line, two 11/2 ton anchors off either side and the fifth anchor weighing 2 ton, straight off the stern. After working an area, the crew would loosen off the side and stern anchors, while tightening the ones on the bow, thus, moving forward. These anchors came off the Lygnern when she sank off Fremantle Harbour in April 1936. The dredge was stripped of its boiler and machinery in 1956 and abandoned at this site. Since that time it has remained insitu and is gradually degrading. In recognition of the historical significance of the cement industry to the development of the region and the role of dredges in that industry, the Belmont Historical Society placed a commemorative plaque near the site in 1996. No evidence of this plaque was found in the 2021 site visit.

Integrity/Authenticity

Integrity: Low Authenticity: Low

Condition

Poor

Uses

Historic Themes

Creation Date

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