OS ACPM Pty Ltd v Mining and Energy Union

This appeal came out of enterprise bargaining in the black coal mining industry. OS ACPM Pty Ltd supplied employees to perform work in black coal mines operated by BHP subsidiaries in Queensland and New South Wales. The Mining and Energy Union was acting as the default bargaining representative for its members and was trying to negotiate enterprise agreements to cover OS employees.

The bargaining process stalled because the parties disagreed about what key award clauses meant. That is an important commercial detail. This was not an abstract legal argument. The dispute affected how OS could roster employees, how public holiday coverage could be arranged, and whether long shifts with a rostered overtime component were permitted under the award structure relied on by the parties.

The Court’s introduction records that the disagreement concerned clauses in the Black Coal Mining Industry Award 2010 and the Black Coal Mining Industry Award 2020 dealing with public holidays and shiftwork. The union brought proceedings seeking declarations about the proper construction of those clauses. The primary judge accepted the union’s interpretation. OS then appealed to the Full Federal Court.

The first issue was the public holiday clause. In the 2020 Award, clause 29.5(a) said that on an agreed date the employer would nominate which public holidays would be worked in the following 12 months by relevant employees, provided that work would not be carried out on two of those holidays. The 2010 Award had materially similar wording in clause 27.5(a).

The argument was about the level at which that proviso operated. The union said it required two public holidays each year on which the workforce collectively would not work. OS said the clause operated employee by employee, so each employee had to have two nominated public holidays on which they would not work, but those days did not need to be identical across the workforce.

That difference matters in any operation that needs coverage across weekends, nights and public holidays. A collective shutdown model is much more restrictive than an employee-by-employee model. It can affect staffing, customer commitments, contractor deployment and the economics of continuous operations.

The second issue was the shift-length clause in clause 15.1 of the 2020 Award. Clause 15.1(b) said the employer may determine the shift length to be worked where the ordinary hours of the shift do not exceed 10 hours. Clause 15.1(c) said a shift may be longer than 10 ordinary hours in specified circumstances, including agreement with the majority of affected employees or resolution under the dispute procedure.

The union argued that references to the ordinary hours of the shift and ordinary hours meant the total length of the shift employees were rostered to work. OS argued that the clause instead regulated only the hours payable at ordinary rates and did not include rostered overtime payable at overtime rates. The available reasons also record that the 2020 Award defined ordinary hours to mean the hours required to be worked by an employee for the payment of their award classification rate, and that the award separately used concepts such as rostered hours and overtime.

The primary judge accepted the union’s construction and made declarations in its favour. On the public holiday issue, the primary judge declared that the words about work not being carried out on two public holidays referred to work not being carried out by the workforce collectively on two public holidays per year.

The primary judge also made a declaration concerning the employment of Mr Stephen Whitton at the Saraji mine during a specified period. That declaration stated that the relevant award clauses required OS to operate a roster of no more than 363 days per year, or 364 days in leap years, and to provide at least two public holidays per year on which maintenance employees collectively were not rostered to work.

On the shift-length issue, the primary judge declared that the relevant words in clause 15.1 referred to the total length of the shift employees were rostered to work. The available reasons note that there appeared to be a drafting error in that declaration, because the reference to clause 15.1(a) should have been to clause 15.1(b).

The available reasons also show that the primary judge considered industrial history in construing the public holiday clauses. The primary judge traced the controversial wording back through earlier coal industry instruments and a 1988 restructuring decision, and treated that history as supporting a more general, workforce-wide application of the public holiday proviso.

That procedural history matters for business readers because it shows how these disputes often arise. A clause may have been used for years, and parties may have strong views about what it has always meant. But once the issue reaches court, the text, definitions and legally permissible context become decisive.

The clearest and safest part of the available material is the Full Court’s formal orders and declarations. The Court allowed the appeal.

On the public holiday issue, the Court declared that under clauses 27.5(a) of the 2010 Award and 29.5(a) of the 2020 Award, the employer must nominate two public holidays on which each employee covered by those awards will not perform work, and those public holidays are not required to be the same for every employee employed by the employer. That directly rejects the collective-workforce interpretation accepted at first instance.

On the shift-length issue, the Court declared that under clause 15.1(b) of the 2020 Award, the employer may determine the shift length to be worked where the ordinary hours of the shift, payable at ordinary rates, do not exceed 10 hours. The declaration expressly states that ordinary hours refers to hours payable at ordinary rates and does not include any rostered overtime payable at overtime rates.

The Court also declared that under clause 15.1(c) of the 2020 Award, the employer may determine that a shift length is to be longer than 10 ordinary hours, payable at ordinary rates, in the circumstances outlined in clause 15.1(c)(i) or 15.1(c)(ii). Again, the declaration expressly states that ordinary hours refers to hours payable at ordinary rates and does not include rostered overtime payable at overtime rates.

Those declarations are commercially significant because they support an employer-side reading of both disputed areas. They indicate that the public holiday obligation was not a requirement for the whole workforce to stop on the same two public holidays, and that the 10-hour reference in the shift clause was not automatically a cap on total rostered shift length where rostered overtime was separately payable at overtime rates.

The available reasons show that the Court was dealing with more than bare text. The catchwords identify an evidence issue about the admissibility of industrial history and common understanding as an aid to construction. The primary judge had considered the history of the public holiday clauses, including earlier coal industry awards and a 1988 restructuring decision, as part of the contextual analysis.

The available reasons also set out the relevant award text in detail. That includes the public holiday clauses in both the 2010 and 2020 Awards, the rostering provisions in clause 15 of the 2020 Award, and the definition of ordinary hours in clause 2 of the 2020 Award. The extract also reproduces the predecessor rostering clause in the 2010 Award, which formed part of the broader context.

For business readers, the practical point is that award interpretation usually starts with the words of the instrument, but the surrounding structure matters. Here, the available material shows the Court had before it definitions distinguishing ordinary hours from rostered overtime, and provisions dealing separately with ordinary hours, overtime and public holiday payments. That structure helps explain why the meaning of a short phrase can have major operational consequences.

What cannot safely be said from the available material is the full detail of the Full Court’s reasoning on the admissibility and weight of industrial history and common understanding. The catchwords show that issue was live, and the appeal result shows the primary judge’s approach did not prevail, but the complete reasoning should be checked before relying on the case for broader propositions about evidence in award construction disputes.

If your business uses award-based rosters, this case is a reminder that drafting details can change the economics of an operation. A clause may look simple, but the legal effect can turn on whether it applies to each employee individually or to the workforce collectively. The same is true for expressions like ordinary hours. In one setting, that phrase may be treated as the whole shift. In another, especially where the instrument separately recognises overtime and rostered overtime, it may refer only to the hours paid at ordinary rates.

Businesses should also note the bargaining context. This dispute arose because the parties could not agree on what the award meant, and that disagreement blocked enterprise agreement negotiations. That is common in practice. If your proposed agreement assumes a particular roster model, but the underlying award position is contested, bargaining can stall and the dispute can spill into litigation.

Operationally, employers should review how their rosters, payroll systems and communications describe long shifts. If a shift includes both ordinary hours and rostered overtime, the labels used in payroll and rostering systems should match the legal treatment under the applicable instrument. Public holiday planning should also be checked carefully. A business should not assume that a clause requiring two non-worked public holidays necessarily means a site-wide shutdown, but it should also not assume this case applies outside the wording actually considered by the Court.

Most importantly, businesses should not rely on this summary alone for operational changes. The available material includes the declarations and part of the reasons, but not the complete reasons in full. Before changing rosters, public holiday arrangements, payroll coding or bargaining positions, review the full judgment, the current award text, and any enterprise agreement or consultation requirements that apply to your workforce.

The Full Court judgment is dated 7 May 2026. The appeal was from Mining and Energy Union v OS ACPM Pty Ltd [2025] FCA 200. The available material identifies the matter as a Full Court appeal in the Federal Court of Australia, Fair Work Division, and records that the hearing took place on 11 November 2025.

This page remains at review status because the available court material does not include the complete reasons in full. The declarations and the parts of the reasons that are available are enough to explain the dispute and the appeal outcome with confidence, but they are not a complete substitute for the full judgment when advising on operational changes.