A horseman rides near a pontoon bridge spanning the Potomac River in Berlin (now Brunswick), Maryland, 1861.
Pontoon bridges have been in use since ancient times and have been used to great advantage in many battles throughout history.The spelling “ponton” in English dates from at least 1870.
The use continued in references found in U.S. patents during the 1890s. It continued to be spelled in that fashion through World War II, when temporary floating bridges were used extensively throughout the European theatre. U.S. combat engineers commonly pronounced the word “ponton” rather than “pontoon” and U.S. military manuals spelled it using a single ‘o’.The original word was derived from Old French ponton, from Latin ponto (“ferryboat”), from pons (“bridge”).