a serious problem during payout operations. In-line packages would in- 

 crease this problem. A vertical drum with a third flange has not been 

 used for cable handling. A vertical level wind with proper tensioning 

 may alleviate this problem. For a flexible armored cable of relatively 

 short length, a reel should be used for storage and handling on board a 

 ship. 



C a ble Payout Equipment . The major differences between a cable chute 

 and cable sheave are cost and rotational resistance. To reduce bending 

 fatigue, a tensioned cable should be passed over a curved surface of 

 adequate radius. A rule of thumb is that the chute sheave radius should 

 be 400 times the radius of the outer armor wire or 40 times the cable 

 radius, whichever is larger. In general, the cost of a cable chute is 

 cheaper than a large sheave of the same radius. The sheave also requires 

 more deck space. A cable can rotate more freelv within a wide chute than 

 in a narrow groove of a sheave. A torque cannot be transferred through 

 a cable over a sheave. When a nontorque-balanced cable is stretched be- 

 tween two sheaves, a torque is produced in the cable. Because there is 

 no rotation in this section, the torque will not be relieved by spread- 

 ing through the remainder of the cable. However, if one of the sheaves 

 is replaced by a chute, the cable will rotate in the chute and reduce the 

 torque concentration. 



When a large V-groove sheave is used, often the cable leaving the 

 sheave touches the sheave flange. If it touches the right flange as it 

 is payed out, a clockwise torque will be applied to the cable by friction, 

 causing the cable to rotate clockwise and to dumb up the flange. This 

 is not desirable as it causes local erosion of the sheave and induces in- 

 line torque. The key to this problem is to keep the cable clear of the 

 sheave flanges. 



A cable chute is adequate for handling smooth armorless deep-sea 

 telephone cable which is deployed with relatively low cable tension be- 

 cause the chute is kept lubricated, only 90 degrees of arc is necessary 

 and the cable is passed over the chute only once. It has been shown that 

 after periods of operation neither the chute nor the cable showed any 

 substantial wear. A sheave is recommended for handling bare armored 

 cables in high tension. 



Cable Pulling Machines . A traction drum can provide higher pulling 

 force and costs less compared to a linear puller. Rut if the drum uses 

 fleeting knives to keep the cable in place, a torque and twist is induced 

 in the cable. An equal amount of rotation will develop in the cable on 

 each side of the winch. This rotation and torque will build up and cause 

 kinks, especially during the tank loading when line tension is small. Such 

 torque will not occur for grooved traction drums because the cable is not 

 forced to roll across the drum. 



A linear puller can handle cable with in-line packages up to 14 

 inches in diameter and 20 feet long and provide up to 20,000 pounds of 

 pull. This system is too large for ships of opportunitv. Only specialized 

 cable ships are equipped with such handling equipments. 



Hydraulic control and motion compensation devices are desirable to 



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