After negotiations with Hannen, Holland & Cubitts of England who were joined by S A Conrad Zschokke a revised bid was received and on that basis a contract with a target estimate of £8,289,148 and a 4% fee of £331,566 was awarded on 25 July 1952. The contract had provision for a bonus of £350,000 for early completion. There was a penalty for late division of the river and a £1000 penalty for each day past July 1955 that the power station was not ready for service. The target completion date was 1 June 1955.