Pontoon bridges were extensively used by both armies and civilians throughout the latter half of the 20th century.

From the Post-War period into the early 1980s the U.S. Army and its NATO and other allies employed three main types of pontoon bridge/raft.
The M4 bridge featured a lightweight aluminum balk deck supported by rigid aluminum hull pontoons.
The M4T6 bridge used the same aluminum balk deck of the M4, but supported instead by inflatable rubber pontoons.
The Class 60 bridge consisted of a more robust steel girder and grid deck supported by inflatable rubber pontoons.
All three pontoon bridge types were cumbersome to transport and deploy, and slow to assemble, encouraging the development of an easier to transport, deploy and assemble floating bridge.
Pontoon bridges were extensively used by both armies and civilians throughout the latter half of the 20th century.
From the Post-War period into the early 1980s the U.S. Army and its NATO and other allies employed three main types of pontoon bridge/raft. The M4 bridge featured a lightweight aluminum balk deck supported by rigid aluminum hull pontoons. The M4T6 bridge used the same aluminum balk deck of the M4, but supported instead by inflatable rubber pontoons. The Class 60 bridge consisted of a more robust steel girder and grid deck supported by inflatable rubber pontoons. All three pontoon bridge types were cumbersome to transport and deploy, and slow to assemble, encouraging the development of an easier to transport, deploy and assemble floating bridge.
Pontoon bridge