Why every lost steamship returning would paralyze world trade

What happens if every unpreserved steamship reappears in a random port, restored to its condition one year after commissioning?

Port congestion could halt trade and threaten food supplies, while enormous quantities of returned ships, fuel, and possible cargoes would overwhelm disposal and commodity markets.

The scenario restores every unpreserved steamship to its condition one year after commissioning and places the ships in random ports. That includes more than 2,700 Liberty ships as well as trawlers, passenger liners, naval vessels, and smaller steam craft. Nuclear-powered vessels would also qualify because their power plants use steam. The resulting congestion could stop ordinary trade and threaten food supplies. Scrap steel, pre-nuclear steel, coal, and oil would arrive in quantities capable of overwhelming their markets. If original cargoes returned too, weapons and the reappearance of late slave ships would create further practical and political problems. Moving ships to offshore anchorages could free berths, but ownership and hazardous materials would still require attention.