Last summer, water began gushing through concrete that was supposed to last 100 years but could not make it to the first ship. The Hill analysts had warned that the consortium’s budget for concrete was 71 percent smaller than that of the next lowest bidder. The budget also allotted roughly 25 percent less for steel to reinforce that concrete. Then there is the lock design. Tugboat captains say they cannot safely escort the larger ships because the locks are too small with too little margin for error, especially in windy conditions and tricky currents. In fact, in a feasibility study obtained by The Times, the Panama Canal Authority had earlier concluded that the tugs needed significantly more room.