The Panama canal has been a massive boon to world trade.
Ships are now becoming so large, however, that they are starting to exceed the Panamax standard (the size of the largest vessels which can pass through).
This limitation is caused mostly by the dimensions of the canal locks. Today’s invention is a way for huge vessels still to make use of this canal and others around the world (without enormously costly increases to canal dimensions).
Imagine a ship like the one on the left which has an enormous draft and is supported and stabilised by two large outriggers whilst at sea.
Just before it arrives at a canal lock, the outriggers engage with tractor units (orange), running on rollers, which can move along the two-metre wide concrete towpath on each side.
These can be hydraulically jacked up to take a sizeable fraction of the weight, so that the ship’s hull need not be fully accommodated by the depth of the canal, allowing it to carry its cargo between oceans.
Each of the tractor units would need to be based on this kind of technology,
http://pinterest.com/pin/262475484504910710/ which might mean laying some extra reinforced concrete wider than 2m.