On: The Grand Unified Theory of Rogue Waves

[echelon]

Why don't we design submersible container ships? Are the energy costs of displacement while moving entirely underwater too expensive?

[usrusr → echelon]

Cargo handling time at port is a big cost factor, it would be very hard for a sub to provide comparable access for loading/unloading.

[learn_more → echelon]

Perhaps the density of the cargo is, on average, too low. The amount of ballast needed would make it impractical.

[slashdev → echelon]

It would definitely use more energy, and container shipping is all about efficiency. It's a non-starter.

[usrusr → slashdev]

Many military subs are actually faster submerged than surfaced.

The wave drag (or wave resistance, to disambiguate from the shock wave drag of supersonic aerodynamics) referenced in sibling comment is the energy contained in the waves created by a surface vessel. The details that you'd have to understand to optimize a hill shape are quite complicated, but for a simple surface vs sub comparison it's enough to know that surface waves exist and that they contain energy that is projected away. A sufficiently submerged vessel does not create those.

[petschge → slashdev]

are you sure? wave drag is a big part of the total drag ob a ship. which is also why dolphins go pretty fast with much less than one horse power.

[ceejayoz → echelon]

Submarines require a fantastically higher amount of maintenance to keep running.

[porknubbins → ceejayoz]

After reading Outlaw Sea I think even the maintenance that is required on container ships is frequently skipped or corners cut, at least by smaller operations.

[mjevans → echelon]

Are you suggesting a submersible that might run underwater only temporarily, during the storms, to avoid the undulating surface?