why do we need locks in the panma canal??

Answer 1

According to
http://www.eclipse.co.uk/~sl5763/panama.htm

it was determined in 1883 (when the French were working on it) that the tidal ranges of 20 feet for the Pacific side vs. 1 foot for the Atlantic side would be a danger to navigation. Adding locks did end up with the advantage that a lot less excavation across the land was needed.

Answer 2

Locks are required in any canal that undergoes a dramatic change in elevation. They are also required where 'flow control' is necessary, but this is a much rarer occurrence.

In the case of Panama, the elevation change between the two oceans and between each ocean and the interior require a 'lock' concept.

As a side bonus, the locks also help control the 'flow' aspect, which allows safer navigation entering/exiting to either coast's tide profile.

Answer 3

Simple answer, the two oceans are at different elevations. Guess Sea Level means different levels based on which ocean you are in. Also when going across the country, its best to keep the water at one or two different levels, and prevent currents from the ocean to ocean from forming. Dams allow the ships to change elevations.

Answer 4

We have to account for the altitude of Panama above sea level. We lift the ships to move them from one ocean to the next.