Xerxes' Pontoon Bridges Xerxes' Pontoon Bridges Xerxes' Pontoon Bridges were constructed in 480 BC during the second Persian invasion of Greece upon the order of Xerxes I of Persia for the purpose of Xerxes’ army to traverse the Hellespont (the present day Dardanelles) from Asia into Thrace, then also controlled by Persia (in the European part of modern Turkey). The bridges were described by the ancient Greek historian Herodotus in his "Histories", but little other evidence confirms Herodotus' story in this respect. Most modern historians accept the building of the bridges as such, but practically all details related by Herodotus are subject to
Flexible cable designs. These are sometimes called “chain-suitable,” “high-flex,” or “continuous flex” cables. A higher level of flexibility means the service life of a cable inside a cable carrier can be greatly extended. A normal cable typically manages 50,000 cycles, but a dynamic cable can complete between one and three million cycles. Flexible cables can be divided into two types: those with conductors stranded in layers inside the cable, and those that have bundled or braided conductors. Stranding in layers is easier to produce, and therefore usually less expensive. The cable cores are stranded firmly and left relatively long in several layers