I’ve been reading a lot lately about how supertankers and massive container ships may take two miles to slow to an emergency halt (even with the engines full astern).
Today’s invention offers a way for ships to stop much more rapidly (if they are travelling in a canal).
On the left, we see a ship in cross section moving down a canal at say 10 m per sec. This vessel has strong beams built in which are wider than the canal.
When an emergency stop is required, the beams are allowed to make contact with reinforced ramps on either bank. The kinetic energy of the ship is exchanged completely for potential energy, as the ship is lifted higher in the water (right hand image).
A simple energy-based calculation shows that a ship which engages with ramps angled at 10 degrees to the horizontal will be brought to a stop in about 12m (with no reverse thrust or anchors).