Comsteel Unanderra ca 1960
(Courtesy Bluescope Steel (Ref 1)

Comsteel was a special steels manufacturer based in Waratah, Newcastle, in which BHP had progressively acquired shares from 1929 until by the 1950s it was a BHP subsidiary. For many years its product range included hot rolled stainless steel sheets. With the company in the 1950s recognising a growing demand for higher quality cold rolled stainless steel in the lower cost coil form, arrangements were made for Australian Iron & Steel (AI&S) at Port Kembla to provide feedstock for a new manufacturing facility at Unanderra close to the Port Kembla works. The site chosen was a literally greenfield site, on what had been the Cochrane family’s farm. Wollongong City council approved the building development including site civil works in November 1957. The civil works required were substantial, including the diversion of a creek (Duck Creek) and raising of the site level generally. (Even the latter could not later prevent major disruption to operations during a major flood in 1966.)

Comsteel, Newcastle ca 1950
(Courtesy of the Mayfield 1950 Jubilee Booklet, 1950)

Construction started that year with the plant ready for operation by late 1959. The cost of the new facility was substantial – £518,000 for the building alone, and some £M4 for the project overall including equipment. Its capacity was `10,000 tons/year (more than sufficient to meet the full Australian demand of the time) but was able to be expanded to 18,000 tons/year.  The plant was designed to treat and then cold roll stainless steel coiled strip which had been produced in an electric arc furnace and then hot rolled at AI&S. It employed a new technology concept, a multi-roll cluster mill, designed by Sendzimir of the USA. The mill was capable of producing strip up to 1075mm in width.

Sendzimir Mill, Unanderra ca 1960
(Courtesy of Bluescope Steel (Ref  1)

First production took place on September 1, 1959, the event being hailed as an industrial milestone in Australia. The official opening by Mr (later Sir) Colin Syme took place on 6 April 1960, newspapers noting that the plant was the first of its kind in Australia. An interesting and unusual aspect of the plant was its well laid out and maintained gardens. These were a major aid in keeping down site dust and dirt in an operation seeking to produce a high quality surface finish product.

The demand for even higher quality surface finishes resulted in further plant being installed, with building extensions approved by Wollongong City Council in July 1965 and new plant becoming operational by April 1966. This included a bright annealing line at a cost of some £M0.75 and a new continuous strip grinding and polishing line which took the overall cost to around £M1.25.

By the end of the 1960s increasing Australian demand was pointing to a capacity increase and in September 1969 a major expansion was announced. A second Sendzimir mill capable of rolling strip up to 1500mm wide was installed to keep up with the world trend for wider product. Including associated plant and buildings this project ultimately cost some £M17. Employment at the Unanderra works increased from 256 to 360 by 1972 when the new facilities were operating.

Events in the Australian economy were however to intervene, and by 1975 production was much affected by a recession, a problem faced by other Port Kembla producers also. In addition, imports, particularly from Japan, exacerbated the situation and made it necessary for the company to seek temporary tariff protection from what was shown to be, in many cases, ‘dumped’ product – that is, material being sold for less than its cost of production in its home country.

By the start of the 1980s, demand and production recovered to more normal levels, and operation continued at around 25,000 to 30,000 tonnes per annum. However over the next few years surplus capacity around the world resulted in increasing levels of competition from imports, from an increasing range of countries. Several technology shifts had a significant impact also. The first was the advent of hot strip rolling on smaller dedicated mills rather than the large, higher capital cost hot strip mills of integrated steel plants. The second (and one which was to have echoes in the last years of the Unanderra site) was the potential for the continuous casting of stainless steel strip. Both these technologies impacted on scale economies and put major pressure on costs.

The company assessed these technologies, even going to the stage of establishing a pilot (and later commercial) scale plant to investigate casting technology in particular (see below). While the result was a technical success, economic assessment in the context of the Australian market size indicated that the likely capital cost and the domestic market size were not compatible. Without the ability to change process, market share for the plant was progressively eroded.

Finally it was decided that AI&S could no longer supply the hot rolled feedstock to Comsteel. While imported hot rolled coil was used for a period the operation was uneconomic and ultimately the plant ceased production operations in the mid 1990s.

Strip Casting Technology – Project M.

In 1988 the Comsteel Unanderra site saw a very new technology arrive. BHP and IHI (Ishikawajima-Harima Heavy Industries) of Japan agreed to cooperate on the development of new continuous casting technology. The process, rather than casting slabs for rolling to strip, aimed at producing strip directly by casting, for either direct use or subsequent cold rolling. This technology offered the same type of step change advancement as had the introduction of BOS steelmaking, or continuous slab casting elsewhere in the steel process. It was not the first association for the two companies – IHI were in fact the designers of Port Kembla’s No 5 Blast furnace commissioned in 1972, and since 2011 the single remaining blast furnace operating at Port Kembla. The initiative went under the name of ‘Project M’ and was located at the Unanderra plant.

In the first stage a pilot plant was constructed utilising the twin-roll process to cast five tonne strip coils 800mm in width. Initially focusing on stainless steel grades, the pilot plant had success with 304 stainless material at 800mm width in 1991, and then moved on to produce a series of 1300mm wide low-carbon coils in 1992. The results were to encourage the partners to approve the construction of a commercial scale plant in 1993 with the aim of demonstrating the strip casting of carbon steels.

This new plant was located in the AIS works, in the plant which had formerly supplied stainless steel for hot rolling at AIS, and thence to Comsteel. It was in operation by 1995, and was able to cast 60 tonne heats of carbon steel into 1345mm wide coils of 2.5mm strip. It operated until 1999 refining the operation, finally undertaking a ‘process capability’ trial comprising twenty nine 50 tonne heats with product coil thickness between 1.9 and 2.0mm. Overall in the project some 35,000 tonnes of product were cast at the facility, the output being directed to a variety of purposes. Much of it was subsequently cold rolled, coated and formed into roofing products for use in Australia. Other material was processed in the US to construction decking material, and in Australia to pipe and tubes.

Casting – Project M Commercial Scale Plant
(Courtesy Powerhouse Museum, Sydney)

At the conclusion of the program it was decided to seek another partner for commercialisation. That resulted in the formation of a new company, Castrip LLC, with BHP and the Nucor Corporation of the US as principal (47.5% each) partners, and IHI as a 5% participant. The role of Castrip was to make the technology and patents for the process available to other producers, and Nucor itself became the first to use the process in a truly commercial plant at Crawfordsville, in the USA. A second US Nucor plant was commenced in 2008 and in September 2016 an order was placed for the first plant outside the US, at the Tyasa plant at Ixtaczoquitlan in Mexico. The outcomes of Project M with its origins at Comsteel seem likely to have a lasting impact on the steel industry.

Reference 1: BHP 75 YearsThe BHP Company, Melbourne, 1960.