The panama canal was completed 6 months early because

The correct answer is :The completion of the construction of the Panama Canal took place six months early because new machines and technologies were invented.
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The preparations lasted three years and the construction of the canal began in 1907. It was a very large company. The workers began their journey at 7 in the morning and rested on Sundays. At dusk they were transported by trains to their homes. In the morning, crews of workers drilled the rock to introduce dynamite. At lunchtime, the workers rested and the dynamiters began their turn. In the afternoon, crews equipped with mechanical shovels loaded the debris into the wagons. At 5 o'clock in the afternoon most of the workers stopped working, but drilling and explosions continued.
The Americans decided to build two sets of gates: one to raise the boats up to the level of Gatun Lake - about 26 m above sea level, at the exit of the canal to the Caribbean - and another to lower them at the opposite end of the canal. These gigantic gates, built on the ground, required 3.4 million cubic meters of concrete. Its base had a thickness of 4 to 6 m and the walls, perforated like a hive to empty or fill the gates, measured almost 15 m thick at the base.
The Panama Canal cost the US government 352 million dollars - four times more than the Suez Canal - and claimed 5,609 lives, including accidents and illnesses. Even so, the cost was 23 million dollars less than budgeted and the channel was inaugurated six months earlier than expected, in August 1914.