Deepak Gupta, J.

1. The plaintiff Satluj Jal Vidyut Nigam Limited is a joint venture of the Government of India and Government of Himachal Pradesh formerly known as Nathpa Jhakri Power Corporation (hereinafter referred to as the plaintiff Corporation). The plaintiff Corporation was established for construction and setting up of a 1500 Mega Watt (MW) Hydro Electric Power Project on river Satluj known as Nathpa Jhakri Project. The plaintiff in turn entered into a contracts with various other parties including the defendant for carrying out some portions of the work relating to the construction and erection of the Project.

2. The present dispute relates to Contract No. 3 of 1993 entered into between the parties on 24.6.1993 whereby the plaintiff had entrusted the construction of civil work for a Head Race Tunnel from Station 16042 m to 27295 m, including surge shaft to the defendant. Differences arose between the parties with regard to the method to be employed for the excavation work keeping in view the fact that the geological nature of the rock face encountered during the course of excavation was found to be different from that envisaged at the time of execution of contract.