National Defense: Swimming Tractor

One day last week seven tons of Duralumin "tractor," driven by a twelve-cylinder automobile engine, chugged into the surf of Guantanamo Bay and set out to sea. Instead of sinking, the Buck Rogersian vehicle paddled to & fro at ten miles an hour, turned, charged the beach and landed a party of U. S. Marines.*

The occasion marked the latest tests of the Marines' newest fighting machine, no screwball toy but the result of seven years of trial & error by 325-pound Sportsman-Inventor Donald Roebling. Originally conceived by Wire Ropeman John A. Roebling as...

Want the full story?

Subscribe Now


Get TIME the way you want it

  • One Week Digital Pass — $4.99
  • Monthly Pay-As-You-Go DIGITAL ACCESS$2.99
  • One Year ALL ACCESSJust $30!   Best Deal!
    Print Magazine + Digital Edition + Subscriber-only Content on

Learn more about the benefits of being a TIME subscriber

If you are already a subscriber sign up — registration is free!