Waiver and acquiescence in arbitration bar a party from later challenging the arbitrator's appointment after full participation.

A party that participates in arbitration with knowledge of the relevant facts, files claims and documents, seeks interlocutory relief, and continues without timely protest is precluded from later challenging the arbitrator's appointment or the validity of the proceedings. The governing principle is that a party cannot approbate and reprobate: waiver, estoppel and acquiescence bar an objection where conduct shows informed acceptance of the reference. The challenge to jurisdiction therefore fails when the objection is raised only after substantial participation in the arbitration.

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Issues: Whether the respondents, having participated in the arbitration proceedings without protest, were precluded by waiver, estoppel or acquiescence from challenging the appointment of the arbitrator and the validity of the arbitral proceedings.

Analysis: The arbitration clause contemplated reference of disputes to the named departmental arbitrator, but the court-appointed arbitrator was substituted on the appellant's apprehension of bias. The respondents did not pursue an immediate challenge to that appointment; instead, they took part in the proceedings for a substantial period, filed claims and documents, sought interlocutory orders, and obtained repeated extensions. The principle applied is that a party cannot approbate and reprobate by participating fully in the reference with knowledge of the relevant facts and later questioning the authority of the tribunal. The objection was not confined to challenges raised after an award, but extended to proceedings where the party had knowingly acquiesced.

Conclusion: The respondents were barred from impeaching the appointment and proceedings by their conduct, and the challenge to jurisdiction failed.

Ratio Decidendi: A party who, with knowledge of the relevant facts, participates in arbitration proceedings without protest is precluded by waiver and acquiescence from later challenging the arbitrator's appointment or the validity of the proceedings.

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