4 ms·

Are you saying that the automation of cranes is faster than that of humans and results in a much shorter load/unload time? I would think the unload time would

Are you saying that the automation of cranes is faster than that of humans and results in a much shorter load/unload time? I would think the unload time would be dominated by the time for the crane to move the container physically rather than the CV problem of identifying a container. Automation could just result in labor cost savings rather than decrease load/unload time significantly.

yardie 9y ago
In a port there the big ship to shore cranes and there are the smaller mobile gantry cranes. The smaller gantry cranes look like this [0] and 1 operator may be controlling half dozen simultaneously. There are huge cost savings involved because 1 person can move multiple containers, simultaneously. These systems aren't cheap and it requires more skill closer to IT than your typical stevedore. So it can take years to recoup any savings in labor. Recouping time costs are almost immediate. [0] http://www.konecranes.com/equipment/container-handling-equipment/automated-rmg-armg-system http://www.konecranes.com/equipment/container-handling-equip...
londons_explore 9y ago
If load/unload time were a big $$ problem, I can imagine one could design a system which effectively threw containers on and off the ship. ie. acceleration at 1G upwards on the way out, and freefall on the way in. The same acceleration rates can be used for the automated clamps which lock onto the corners of the containers for movement. Assuming a dockside + ship is 100 yards wide, a one second lock/unlock time for clamps, that should work out at 14 seconds per container. Assume we have a grid of cranes over the ship, able to pick up every container on top at once. Assume the worst-case complete unload of the whole ships capacity (10,000 40 ft containers on the largest vessels), and reload of another complete load. That comes out as 8 minutes! Current loading times are multiple hours for even a partial unload of a much smaller ship. That tells me that there isn't enough $$$ involved to get serious engineering efforts to make it quicker.

yardie 9y ago

In a port there the big ship to shore cranes and there are the smaller mobile gantry cranes. The smaller gantry cranes look like this [0] and 1 operator may be controlling half dozen simultaneously. There are huge cost savings involved because 1 person can move multiple containers, simultaneously. These systems aren't cheap and it requires more skill closer to IT than your typical stevedore. So it can take years to recoup any savings in labor. Recouping time costs are almost immediate. [0] http://www.konecranes.com/equipment/container-handling-equipment/automated-rmg-armg-system http://www.konecranes.com/equipment/container-handling-equip...

londons_explore 9y ago

If load/unload time were a big $$ problem, I can imagine one could design a system which effectively threw containers on and off the ship. ie. acceleration at 1G upwards on the way out, and freefall on the way in. The same acceleration rates can be used for the automated clamps which lock onto the corners of the containers for movement. Assuming a dockside + ship is 100 yards wide, a one second lock/unlock time for clamps, that should work out at 14 seconds per container. Assume we have a grid of cranes over the ship, able to pick up every container on top at once. Assume the worst-case complete unload of the whole ships capacity (10,000 40 ft containers on the largest vessels), and reload of another complete load. That comes out as 8 minutes! Current loading times are multiple hours for even a partial unload of a much smaller ship. That tells me that there isn't enough $$$ involved to get serious engineering efforts to make it quicker.