Pedro Miguel Locks, east chamber, showing outlet in east wall and construction of lower main gate. View looking north. There is one pair of locks here to accommodate vessels going both ways. Each has a lift of 30 1/2 feet. Vessels will not be allowed to go through the locks under their own power. Electric towing engines running on cog rails on the tops of the walls will tow the vessels through. The usual number of engines will be four and it will take about 30 minutes to pass through each chamber, or three hours to pass all the locks.