Feasibility analysis of an 11,000 m vehicle with a fiber optic microcable link to the surface

This paper discusses the feasibility of an 11,000 m underwater system that utilizes a battery-powered vehicle connected to the surface by a single channel fiber optic microcable. The proposed system has several benefits over conventional remotely operated vehicle (ROV) solutions for ultra deep applications. It avoids the prohibitively expensive tether and winch otherwise necessary for 11, 000 m work. Due to its relatively small size and low weight, the system allows for fast mobilizations and use on a variety of platforms. This concept also allows the vehicle to travel tens of kilometers away from the surface ship, which would be beneficial in applications where the surface ship has limited maneuverability such as under-ice work in the Arctic. This analysis focuses on the feasibility of using a microcable tether with a 450 N (100 lb) breaking strength housed in a constant force payout canister. Tension in the cable is modeled for current conditions in three areas of interest to the scientific community - a deep Western Pacific trench, the Arctic and the Juan de Fuca Ridge - and found to be well within the microcable's working limit.