[antisthenes]

> The 1930s German zeppelins had peak speeds of about 80 mph, cruising of around 70 mph. That made for about a 30 hour Atlantic ocean crossing.

The distance between NY and London is ~3500 miles, which would make that trip 50 hours at the very minimum, not 30 hours like you suggested.

Travel to other countries would take even longer, unless your plan is to just ferry people over the Atlantic and distribute them via train after.

[dredmorbius]

You're right. I'd underestimated crossing times, though prevailing winds also cut time to as little as 43 hours eastward. From Wikipedia's page on the Hindenberg (unattributed):

"The ten westward trips that season took 53 to 78 hours and eastward took 43 to 61 hours."

Given that high-speed land-based rail would be an option, the ferry-to-rail option seems a strong contender, actually.

Remember: the whole concept of moving any significant distance at a rate of more than a few miles an hour is quite modern.