52. Interest

(1) The parties are free to agree on the powers of the tribunal as regards to the award of interest.
(2) Subject to any contrary agreement by the parties, the tribunal’s powers as regards to the awarding of interest shall be in accordance with the substantive law governing the claim for which an award of interest is sought.
(3) Unless otherwise agreed by the parties, and subject to any contrary provision of any applicable law referred to in subsection (2), the tribunal’s powers to award interest shall include (but shall not be limited to) the following powers:
(a) The tribunal may award simple or compound interest from such dates, at such rates and with such rests as it considers meets the justice of the case —
(i) on the whole or part of any amount awarded by the tribunal, in respect of any period up to the date of the award; or
(ii) on the whole or part of any amount claimed in the arbitration and outstanding at the commencement of the arbitral proceedings but paid before the award was made, in respect of any period up to the date of payment.
(b) The tribunal may award simple or compound interest from the date of the award (or any later date) until payment, at such rates and with such rests as it considers meets the justice of the case, on the outstanding amount of any award (including any award of interest under subsection (3) and any award as to costs).
(4) References in this section to an amount awarded by the tribunal include an amount payable in consequence of a declaratory award by the tribunal.