The use of tubing or a jacket to manufacture a cable or modify a cable is well-known. The tubing or jacket introduces protective attributes such as weather-resistance, insulation, chemical resistance, fire resistance, abrasion resistance, EMI shielding, etc. which typically require that the tubing or jacket be a continuous covering. Stretchable tubing, heat shrinkable tubing, and jackets with zippers, snaps, or Velcro-like adhesives are commercially available (see "The Zipper Tubing Co." for example). The present invention can be understood by considering the problems encountered while trying to protect exposed structures such as cables, poles, pipes, towers, etc. from attack by animals (and plants). For example, buried cables may be attacked by burrowing animals or animals that dig holes. Underwater cables will often be targeted by fish (including crustaceans) as potential food, as intruders, as building materials, or for refuge. The presence of certain marine biology can in turn attract other species of marine biology, compounding the problem. Suspended cables such as power lines or telephone/cable-TV lines may provide a friendly environment which could encourage plant growth or attract animals such as birds, bats, cats, squirrels, rats, opossums, raccoons, snakes, monkeys, koalas, etc. The presence of plants can add unnecessary weight to, create fire hazards for, attract animals and other plants to, and obscure the location of the exposed structure.
Animals may shorten the useful life of cables by eating, biting, clawing, or rubbing the cable (which might produce catastrophic results or create an opportunity to inflict further damage by other animals, plants, and environmental factors such as moisture, heat, cold, wind); through biochemical means; or by hanging from/sitting on the cables. Thus there is a need for a protective, configurable sheath (also referred to as a configurable sheath or simply as a sheath) which can be attached to new and existing exposed structures, including cables. Various factors such as weight, ease of customization, upgrade, repair, installation, and removal will influence sheath design considerations. Animals may create cavities in trees or poles and animals may climb on trees, poles, towers, pipes, or ducts (as well as into pipes and ducts). These acts may result in the destruction of or loss of functionality of the exposed structure itself (or equipment such as electrical or monitoring devices attached to the exposed structure). Plants such as vines may attach to the exterior (or interior) of an exposed structure, introducing mechanical stress, creating possible fire hazards, and attracting animals (and plants). Small animals may bring building materials and leave waste products in a duct. Existing protective devices such as barbed wire tend to be heavy (since it needs to be self-supporting and is targeted at large animals) and it employs a fixed pattern of barbs (so it is not upgradeable or configurable on-site). Typically, barb wire is used only for containment and is not well suited for preventing interference with an exposed structure. Thus there is a need for a configurable sheath which can be attached to new and existing exposed structures in addition to cables. The protective, configurable sheath design can be customized or tuned for use with a variety of exposed structures (cables, pipes, tubing, ducts, chains, wiring, trees, poles, towers, antennae, fences, vehicles, animals, etc.). The tuning process may involve adding, remove, or modifying passive or active components (features). A sheath which includes one or more embedded or attached active components can be described as a protective intelligent configurable sheath or simply an intelligent sheath. In certain situations the functions of a configurable sheath with passive and/or active components can be provided by the judicious placement of the components on or within the exposed structure. The sheath base material can be omitted. A sheath which includes active and/or passive components but no sheath base can be described as a protective structured configurable sheath or simply a structured sheath.
Exposed structures are often difficult to maintain or protect because these structures are extended in one or more dimensions. Determining how and from where the exposed structure is being threatened (plants, animals, environmental hazards, machines) and initiating an active response (on some level) can be crucial for the long-term viability of the exposed structure. In addition, knowing the magnitude and location of the threat may influence the choice and magnitude of the response. It may be desirable to increase or reduce the visibility of the exposed structure. For example, in many instances hanging cables are difficult to detect by electrical or magnetic means; with ionizing or non-ionizing radiation such as electromagnetic (EM) or acoustic radiation; by the presence of chemical compounds in the air; or by the manner in which they modify the local environment. Hanging cables can create hazards for airborne objects such as planes, helicopters, gliders, birds, bats, etc. and surface-dwelling animals. Buried or underwater cables may be difficult to detect using acoustic, neutron or EM radiation, or by electrical or magnetic means. Poles or antennae may represent flight hazards or obstructions in some situations and targets in other situations. The use of a configurable sheath would be beneficial for these and related applications. Prior devices and methods do not address these concerns.