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
Cable reel Cable reel A cable reel is a round, drum-shaped object such as a spool used to carry various types of electrical wires. Cable reel which can also be termed as drums have been used for many years to transport electric cables, fiber optic cables and wire products. Cable reels usually come in four different types, each with their own uses: wood, plywood, plastic and steel. Wooden drums come in three different varieties: steel-tyred for multiple use, export for sending abroad, and one-way drums for single trip use. Wooden drums can carry heavy loads and are constructed in resinous wood. Discarded