Editing Cable ferry (section)

==Effect on navigation==

Cables can hinder other navigation or pose a hazard. Whether a risk exists, and to which degree, depends on the situation (nature of body of water and extent of shipping) and on the type of cable(s):
*Overhead wire ropes suspended over shipping height.
*Ropes suspended at operating level, permanently or temporarily.
*Ropes held on the water surface by buoys.
*Cables suspended underwater, permanently or temporarily.
*Ground cables normally resting on the bottom, pulled to the surface near the ferry.

[[File:Catenaries_of_a_small_cable_ferry.png|thumb|Possible forces and catenaries for a small cable ferry with chain or wire rope compared.]]

Only the first type normally presents no risk for other vessels, as evident in the 15 reaction ferries of this type in Switzerland. Suspended cables near the water surface block navigation and are dangerous especially in strong currents and if difficult to see. The ropes of reaction ferries attached to one shore and suspended by buoys block the river on one side of the crossing ferry and can be made highly visible. The greatest risk comes from cables that are held underwater to a lesser degree than anticipated or are not visible at all.

Suspended cables (ferry to shore or to water bottom) form catenaries of a shape (entry angle and depth) that depends on the cable weight and amount of tension. Chains are in general rather heavy and can function even with very steep catenaries going to the bottom within very short distances, except very near the shore. As they are also easy to see, the risk to other navigation is usually minimal, as is evident with the 6 or so chain ferries in southern England operating in waters with heavy shipping. In strong water currents, the catenaries become more stretched and chain collisions have occurred. Wire ropes are lighter than chains of the same strength and may be operated under strong tension, both giving rise to shallow catenaries which may be difficult to judge or even see.

Some cable ferry operators warn vessel operators to exercise caution. They may indicate distances to keep clear, special lights, or that the depth of the cable is unknown, both when the ferry is stationary and when it is operating.<ref name="NSW">{{cite web |title=Navigable depth across cable ferry wires |url=https://www.nsw.gov.au/topics/using-waterways/restrictions-and-closures/marine-notices/sy1939-sackville-cable-ferry |website=NSW Government |publisher=NSW Government: Transport for NSW |access-date=3 October 2023 |url-status=live |archive-url=https://web.archive.org/web/20231003002719/https://www.nsw.gov.au/topics/using-waterways/restrictions-and-closures/marine-notices/sy1939-sackville-cable-ferry |archive-date=2023-10-03 |format=Website |date=2023}}</ref>