Pontoon bridge in 638. The army of the Umayyad Caliphate built a pontoon bridge over the Bosporus in 717 during the Siege of Constantinople (717–718). The Carolingian army of Charlemagne constructed a portable pontoon bridge of anchored boats bound together and used it to cross the Danube during campaigns against the Avar Khaganate in the 790s. Charlemagne's army built two fortified pontoon bridges across the Elbe in 789 during a campaign against the Slavic Veleti. The German army of Otto the Great employed three pontoon bridges, made from pre-fabricated materials, to rapidly cross the Recknitz river at the Battle on the Raxa
Junk raft 28 August 2008. On the way, they gave valuable water to record-holding ocean rower Roz Savage, also on an environmental awareness voyage, when her supplies dwindled. The construction of the JUNK Raft began in April 2008 and was finished the following month. The huge undertaking of constructing a seaworthy raft from "junk" was aided by volunteers from the environmental education programs of: Bell Elementary, Green Ambassadors, Muse Elementary, Santa Monica High School, and Westbridge School for Girls. The volunteers lent a hand by cleaning bottles, fastening bottle caps, and stuffing them into the recycled fisherman's net pontoon forms.<ref name="junkraft.blogspot.com/2008/04"></ref> Junk