Abstract: The fairing disclosed has a streamlined, segmented, tail portion (63). The two-cable (40) passes through a hole (20) in the nose portion (18). The hole has a large clearance on the cable which allows frictionless rocking of the fairing side-to-side. This prevents any misalignment of the fairing from being locked in by friction. In addition, the segments (80, 90) are either provided with a physical mis-alignment control (84, 95), or the segments may be supported in tension, so that the individual segments do not rub against each other. Pliable links (101;112) are provided between segments that could otherwise rotate freely relatively, to give some torsional stiffness to control the fairing during winching.

Abstract: A long strut between a sea-platform and the ocean bed needs to have its weight supported. Otherwise, much of its strength is used merely in supporting itself. The strut disclosed is made in sections, joined typically by screw threads. The joints need to be inspected periodically. The hollow sections of the strut have their buoyancy disposed internally, yet with the joints exposed internally for inspection by a probe that passes down inside along the length of the strut. The vulnerable joint area is made accessible to the probe. When the joint area includes welds, they too are vulnerable and need to be inspected; the fact that the buoyancy forces also have to be fed into the strut at the joint areas makes for even greater difficulty in providing access for the probe to all the places that need to be inspected. This access is provided in the various manners as shown.

Abstract: Buoyancy apparatus is provided which allows two or more air canisters (43,45) to be mounted one above the other on a section (7) of a strut, without touching the delicate sides of the highly stressed part of that strut section. The canisters need not be of the same length as the section, and each may be of a length determined by the differing manufacturing economies of each. By removing this manufacturing restraint, it is economically possible to produce a strut in the form of a practical tether for a tension-leg platform for deep ocean use. The buoyancy canisters are held in place by tension cords (54,56,58) which attach flotation abutment plates (57,59) to a bulbous and relatively unstressed end (8) of the strut section. The strut, together with its buoyancy, may be deployed by screwing the strut sections one to another.

Abstract: A fairing and a fairing assembly for towed underwater cables is provided, having two different embodiments of fairings. In the first embodiment, each fairing has a flexible nose portion and a substantially rigid tail portion having separable halves, with the connection between the nose portion and the tail portion being by way of a flange at each side at the rear of the nose portion fitting into a channel at the front of each of the half pieces of the tail portion, and with the channel being interrupted by a shear block which is accommodated by a discontinuity in the nose portion flanges. A special arrangement is made having half-length nose portions, and using a flexible link between at least certain ones of adjacent fairings, where the half-length nose portion accommodates a ring secured to the periphery of the cable.

Abstract: A buoyancy system for large scale underwater risers is provided, comprising a plurality of canisters. Each of the canisters extends partially around the circumference of a riser--usually, two canisters and the support structure surround a riser--and a plurality of canisters is associated with each riser section. Air is injected into the lowermost canister or canisters, at a pressure sufficient to displace the contained water within the canister; and when the water level within a canister is lowered sufficiently that a port in a cross connected tube is uncovered, the compressed air enters the tube and travels upwardly to the next canister above, where the unwatering sequence is repeated. Because very great depth can be accommodated--3,000 meters or more--provision is made for reflooding the canisters in the event of an emergency. Additionally, because of pneumatic considerations, different configurations of cross tube are provided for installation in the canisters at varying depths.

Abstract: Apparatus for launching, towing and recovering a submersible and towable body from a vessel includes a saddle, a winch and cable spooling and tension apparatus. The saddle includes a roller box which is rotatable about the axis of the tow sheave to maintain constant pressure against the cable during towing. A skewable A-frame for lowering the saddle near the water surface includes a transom arm which is pivotally mounted to the transom and to the tow sheave. The winch may be a multi-drum assembly, where the drums are co-axially mounted; and the drums are rotatably mounted in peripheral bearings at each end, which are mounted in the ends of the winch enclosure. The winch enclosure has a cover plate with a transverse slot to permit reeling and unreeling of cable from a drum. A latch mechanism provides for positive locking of a drum for rotation or non-rotation, depending on whether it or another drum is the one on which cable is being reeled or unreeled.