Towed undersea cable plows are dynamic systems that have two cable structures, a tow cable, and a telecommunications cable. A numerical simulation has been developed to predict the surge motion of the plow, and the dynamic tension in telecommunications cable. The model is used to compute motions and cable tension after a change in soil resistance, and during harmonic oscillation of the ship tow-point.
Telecommunications cables must be buried when placed where objects that serape the sea floor may break them. Burial is often accomplished by placing the cable in a trench dug with a "sea-plow." The basic plow configuration is a sled towed by a surface ship. A blade extending below the sled digs the trench as the plow is towed. Cable is lowered from the ship to the plow, and is passed through the plow into the trench. Burial operations are time consuming and expensive, because plows must be towed slowly, and the buried cable must be armored to survive rough handing. The cost of burial operations has motivated the development of a new cable plow to bury unarmored, relatively light and weak cables at speeds greater than 1 knot. Deployment of light cables presents three significant challenges,
cable tension in the trench must be low (Burgess, 2000),
hydrodynamic loads may push the telecom cable above and behind the tow wire (Burgess, 1998), and
dynamic tension in the telecom may exceed its allowable working tension.
To overcome these challenges the dynamics of the burial system must be understood, and thus it is necessary to construct a model that combines the elements of ship, plow, tow wire, and telecommunications cable (henceforth referred to as telecom). A cable plow system is illustrated in Fig. 1.
