Jacket damage


Length of damage

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Look for sharp bend here.

Any wrinkle on jacket?

Look for sharp bend here.

Any wrinkle on jacket?

Any mark here to indicate pullout?

Any cut or missing jacket? Any armor wire exposed? Any birdcage, kinks, dog leg in armor wires?

Look for delamination and gap here

Any mark here to indicate pullout?

Look for delamination and gap here

Any corrosion

Figure 5-6. Cable termination inspection guide.

odes installed, these should be inspected as discussed in Sections 4.2.1 and 5.11.

• All locations where cables cross or are wrapped around pipelines or other cables should be checked at the contact interface for abrasion damage. If abrasion is present or anticipated then chafing gear may need to be installed. This may require the use of lift bags to separate cables. Ideally, crossing cables should be separated and anchored to prevent further contact. The decision and correction method will depend upon the particular installation and needs to be made by the customer or on-site engineering.

• Look for exterior damage such as cuts, abrasions, missing jacket or jute wrap, broken or corroded armor wires, reduction in cable diameter, and other conditions as described in Tables 5-3 and 5-4.

• Where cables are suspended, check for damage at either side of the suspension. May need lift bags to inspect under the cable.

• Inspect under birdcaged armor to locate rocks or other objects that may be trapped in the cage and abrading the cable jacket. Remove these objects and protect the birdcaged section to prevent further intrusions.

5.2.5 Cable Handling

After the fault has been located and its position documented, the cable may need to be raised to the surface so that repair work can be performed. The cable protection method usually dictates the surfacing method to be used. If a cable is buried, it should be unburied by some excavating technique, such as jetting. If the cable is protected or immobilized by a mass anchor system, such as split-pipe, this protection must be removed for an appropriate length to allow surfacing. Split-pipe protection is especially difficult to remove because the bolts used to fasten the two halves of the pipe are often badly ter, a chipping hammer, or an impact wrench can be used to remove these bolts. Diver-controlled lift bags are helpful in raising the protected cable into working position.

Execution plans for cable handling and repair operations are normally prepared by NFESC Code ESC55 in consultation with the UCTs. In most cases, UCT personnel will be direcdy involved with both planning and conducting the operation.

The information below provides personnel a general familiarity with cable handling for repair operations.

The retrieval, redeployment, and handling of most cables require a well thought-out plan that must be executed by experienced personnel. Because of the complexity of this operation, it must be planned well in advance to ensure that all support craft, materials, support and operational personnel, and technical representatives for splicing and handling of the cable are on hand at the right time. Cable Retrieval and Handling.

Cable has a delicate and complex structure and should be handled with care. It should not be loaded beyond its design strength. If a cable is pulled beyond its yielding point, the conductors inside the cable will be per-manendy damaged. It must not be bent beyond the minimum bend radius specified by the manufacturer. If a fairlead sheave or cable chute diameter is too small and is used under high tension, the cable will suffer both electrical and mechanical damage. Therefore, use as large a fairlead sheave as practical and as light a tension as practical in handling the cable.

Cable also has a limited tolerance to twisting. When such tolerance is exceeded, it will either form hockles or kinks. Both can cause permanent damage to the cable conductors and strength members. Therefore, we should avoid strangling the cable by rotating the bitter end. The exterior jacket is usually made of a soft plastic material which is easily cut and scraped. It is not designed to be dragged over sharp metal edges. When handling the cable, be sure to elevate the cable between support points at all times.

A well-equipped splice barge is required to conduct the cable repair operations and is normally used as the command headquarters for die at-sea cable handling operations. Prior to arrival at die site, the splice barge should be outfitted with all necessary cable handling, lifting, and firefighting equipment, mooring winches, splicing hut, crew facilities, and replacement cable section. The mooring winches, auxiliary line handling and lifting equipment, and all fairleads should be mounted and tested to ensure adequate strength. Since the barge will be moored during the operation, other support craft, such as a small boat and a tug or work boat, will be necessary on continuous or standby status throughout die operation. The replacement cable should be tested for electrical continuity and placed on a powered reel having adequate braking and pulling capability or placed on a puller-tensioner winch.

Before starting cable retrieval, a favorable weather window is required so that splicing operations can proceed uninterrupted.

The splice barge is moved over one end of the cable to be repaired and entered into a four-point moor.

• The existing seafloor cable is cut, capped, and a stopper attached to the shoreward end. The seaward end of the cable is marked with a surface float.

• A retrieval line is attached to the stopper and led to the stern cable chute. The line, fairleads, and retrieval winch must be arranged on deck so as not to interfere with the repair cable track.

UIVUttiVVAICtl MAIN I tNANUt AND HtfA/H procedures

• The shoreward end of the cable is raised using the retrieval line and winch to a point where the cable is sound enough to be spliced.

• It may become necessary to haul in short lengths of the cable by securing it with a stopper at the inboard end of the stern chute, cutting the cable, and reattaching the winch line for a new pull.

• The splice hut is placed on station and the retrieved end of the cable is securely stopped off, cut, and placed into the splice hut. The leading end of the new (repair) cable is then pulled into the splicing hut. Cable Splicing. A typical splicing operation is performed by specially trained cable splicing technicians assisted by UCT personnel. When the electrical tests of the cable are completed, the splicing operation should start. During the splicing procedure, the cable over the stern should be monitored to prevent excessive loads and the mooring lines adjusted to account for tidal, current, and wind changes. The cable should also be inspected periodically on the bottom by divers to assure that no chafing is occurring.

When the shoreward splice is completed, the splicing hut is moved clear of the cable payout area. Then:

• The cable tension is taken up on the cable payout reel (or winch) and the cable stoppers removed.

• The barge is then moved on its moor along the cable track while cable is payed-out. The splice must be eased overboard and proper cable tension maintained at all times.

• When the barge approaches an appropriate distance beyond the seaward end of the damaged cable, the cable payout should stop.

• The seaward cable is then retrieved in the same manner as the shore end.

• The barge continues about 200 to 300 feet past this point, allowing the seaward end to be brought onboard.

The point to cut the repair cable must be carefully measured, as the payout and pickup of the cables cannot be used to adjust cable tension once the cut has been made. The cut is best made at high tide, with cables below the maximum allowable tension. The cable ends are brought into the splice hut and electrical continuity tests are performed. After the electrical tests have been completed, splicing operations can start as before. Cable Redeployment. After splicing operations have been completed, the splice hut is removed and cable redeployment is started.

• A stopper is placed on the cable at the stern of the barge and a hauling line rigged to the line-retrieval winch.

• As the barge is hauled back along the newly installed repair cable, the winch and line pulls the cable up over the stern. This movement must be stopped periodically to relocate the stopper and hauling lines and should continue until the seaward cable splice case is on the bottom.

• A stopper is placed on the bow end of the cable and attached to an auxiliary pendant line.

uiviscn MM ten MIMIN/tiMANUt AND repair procedures

• Divers in a small boat attach a stopper to the cable at the waterline at the stern end.

• Using the hauling line, winch, and mooring lines, the barge will move astern until both stoppers are just outboard of the cable chutes, at which time the bow line should be stoppered off on deck.

• A cable saddle is then rigged and made ready to receive the cable bight.

• It is necessary to hold the barge against the prevailing wind or current by pulling on the moorings or with the assistance of tugs or workboats, so that the opposite moorings will be under minimum tension.

• The barge is then moved perpendicular to the cable track so that the slack mooring lines can be rigged above the cable. This mooring line transfer can be done by: (1) running extra lines over the cable, attaching them to the mooring buoys, and then releasing the old mooring lines; or (2) stoppering off the mooring lines on short pendants, removing the ends from the winches and running them over the cable and back onto the winches.

• The repair cable should be made slack by pulling in on the stern hauling line.

• When slack, the cable bight is placed in the cable saddle.

• The cable stopper lines should be lowered into the water, the load of the cable transferred to the cable saddle, and the stoppers removed by divers.

• With the barge perpendicular to the cable track, the cable saddle and bight are lowered to the bottom (this maintains an adequate departure angle).

• When the saddle is on the bottom, the divers remove it from the cable and lay out the slack in a manner to prevent vertical loops and avoid obstructions on the bottom.

If applicable, the cable should be anchored to the seabed using an appropriate anchoring method as described in Section 6.2.2. The barge can then be released from its moorings.

A summary of the operations required for a "typical" cable repair project, with an estimated time required to carry out each operation, is presented in Table 5-5. The estimated times shown in the table are based on good weather and sea conditions. The cable is not anchored to the seabed. The total estimated on-site time required to complete the project is 5 to 7 days.

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