Two towers of height 30 m and 90 m respectively support a transmission line conductor at river crossing. The tension in the conductor is 1600 kg. Weight of conductor is 1·5 kg/m. If the minimum clearance of the conductor and water is 23m and clearance mid-way between the supports is 30.68m, find the horizontal distance between towers. Bases of the towers can be considered to be at water level.