Anthony H. Allen

The applicant trade union referred several grievances to the Ontario Labour Relations Board under section 124 of the Labour Relations Act, alleging that the respondent employers violated the collective agreement by assigning certain work to composite crews of millwrights and ironworkers.

The intervener ironworkers' union argued that the grievances were essentially jurisdictional disputes and should be deferred or dismissed.

The Board held that it had jurisdiction to hear the section 124 referrals but, in accordance with its usual practice, decided to first entertain the jurisdictional dispute complaint filed under section 91 before proceeding with the grievances.

During a hearing into a work assignment dispute between the Millwrights and Ironworkers regarding the installation of a monorail conveyor system, a preliminary issue arose concerning the scope of admissible past practice evidence.

The Board had previously limited past practice evidence to the installation of monorail and package conveyor systems.

When the Ironworkers sought to adduce evidence regarding work on a bridge crane to demonstrate economy and efficiency, the Millwrights objected.

The Board upheld the objection, ruling that evidence of economy and efficiency from other employers must relate specifically to the two types of conveyor systems in dispute to be relevant and admissible.