I believe the weight savings is from the materials/design, not the fact that it collapses.<p>And it seems the advantage of collapsing containers is that you could more efficiently shuffle the empties in complex shipment chains.<p>Would you rather ship 100 containers to the US and have 20 China-bound US shipments and 80 empties come straight back? Or ship 100 containers to the US, take on the 20 China-bound shipments, collapse the 80 empties and have room for 60 more elsewhere-bound US exports you can drop off on the way back?