Where the parties have agreed that there is to be an umpire, they are free to agree what the functions of the umpire are to be, and in particular—
If or to the extent that there is no such agreement, the following provisions apply.
The umpire shall attend the proceedings and be supplied with the same documents and other materials as are supplied to the other arbitrators.
If the arbitrators cannot agree but fail to give notice of that fact, or if any of them fails to join in the giving of notice, any party to the arbitral proceedings may (upon notice to the other parties and to the tribunal) apply to the court which may order that the umpire shall replace the other arbitrators as the tribunal with power to make decisions, orders and awards as if he were sole arbitrator.
The leave of the court is required for any appeal from a decision of the court under this section.