PREVENTING CRUSHED CABLES ON DEEP LOGGING JOBS, INSTALLATION AND SPOOLING

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INSTALLATION AND SPOOLING

GAUGING

To gauge electromechanical cables, measure the diameter twice, with the second measurement at a right angle to the first. By averaging the two figures, you will arrive at an accurate estimate of the cable's diameter. (See Fig. 4.) This method assures you an accurate gauging, since it compensates for any flattening of the cable that may have occurred during winding.

GROOVES

Grooves in running sheaves should be checked to fit the particular cable being used. (See Fig. 5.)

It is important that the cable fit properly in the sheave groove. (See Fig. 6.) If the groove is too tight, the armor wires of the cable will wear quickly and soon break. (See Fig. 7.) If the groove is too wide, the tension on the cable will flatten it, which will also result in uneven wear and premature failure. (See Fig. 8.)

View figures 4- 8.

SHEAVES

Sheaves should be aligned so that the axis of the cable is parallel to a line drawn from the center of the groove of one sheave to the center of the groove of the next sheave. This alignment prevents excessive wear caused by the cable bearing against flanges or dragging across shoulders. This wear will destroy the outer armor wire long before the cable has given even nominal service. Using sheaves with broken flanges has the same undesirable results.

FLEET ANGLES

On installations where the cable passes over a lead sheave, then onto a dru, it is important that the lead sheave be located at a sufficient distance from the drum to maintain a small fleet angle at all times. The fleet angle is the side angle at which the cable approaches the sheave from the drum. (See Fig. 9.)

The best electromechanical cable service is obtained when the maximum fleet angle is not more than 1 ¾ degrees. The maximum fleet angle is the angle between the centerline of the sheave and the cable, when the cable is at the end of its traverse travel on the drum. A lead of twenty-five times the drum width (measured between flanges) will normally establish a suitable fleet angle. Thus a drum three feet wide should be located approximately 75 feet from the lead sheave.

TIPS ON SPOOLING

Make certain the winch drum
is in good mechanical condition: the flanges must be perpendicular to the drum core; and the core surface should be smooth and straight with no dishing. If using a grooved drum, be sure the grooves are the correct size for the cable being spooled and in good condition: the flanges must be perpendicular to the drum core; and the core surface should be smooth and straight with no dishing. If using a grooved drum, be sure the grooves are the correct size for the cable being spooled and in good conditions.
Apply the first layer in a predetermined pattern that can be easily reproduced on all subsequent layers.
Watch crossover points carefully, so that proper position is maintained
Recheck the fleet angle after the second and third layers have been applied to make sure equipment is still in alignment
Maintain proper back tension
for each layer

BREAKING IN ELECTROMECHANICAL CABLE

After a new cable has been installed, it is advisable to run it in a test well for a short period. This gives the component parts a chance to adjust themselves to the operating conditions. Time spent in breaking in the cable will pay off in extended cable life.

The Spooling of Armored Wireline cable on a smooth surface winch drum requires proper handling equipment, plus proven installation techniques. After the cable is installed, the winch operator must also use correct operating methods or the best spooling effort can be lost.

Condition of drum

The winch drum should be in good mechanical condition; the core surface should be smooth and straight with no dishing; and the flanges must be perpendicular to the drum core.

Removing cable from shipping reel

Normal installation requires spooling from the top of the shipping reel to the top of the winch drum. The cable bed layer can travel from left to right or right to left, but a back tension of some form should be held, as the cable is spooled on the winch drum. Proper back tension allows removal of the cable from the shipping reel without cutting into the lower layers and can best be accomplished by using a tension capstan between the shipping reel and the winch. This arrangement not only prevents cable damage on the shipping reel, but allows for the use of pre-calculated tension under controlled conditions.

Proper alignment

For a cable to be spooled properly, the angle from the winch drum to the first fixed point should be correctly established. This is known as the fleet angle and should be no greater than 1-1/4º at the flange. The approximate distance required to develop this angle is found by multiplying the drum width by 25; thus, for every foot between flanges of the drum, a distance of 25 feet is needed to the fixed point.

Basic spooling concept

The main concept of controlled cable spooling is to apply the first layer in a predetermined pattern that can be readily reproduced on the second and all subsequent layers.

During spooling, the cable should lie parallel to the flanges except (or the two cross-over sections where the cable moves across the drum one-half pitch (1/2 cable diameter) to give a full pitch movement per drum revolution.

The area of the cross-over or "break" points covers about 10% of the circumference of the drum. This area Is divided between the two cross-over sections spaced 180º apart, thus creating a counter-balanced effect on the drum.

Establishing cross-over points

The winch drum should have a entry hole on the side of one flange where it joins with the core. This hole should be drilled just slightly larger than the cable and at an angle to allow movement of the cable along the face of the flange without a sharp bend. A clamp or other means should be used to keep the cable from pulling back through the entry hole.

The first cross over point is developed at the entry hole. Using a carpenter's square (held at right angle with core and flange) and a chalk stick, draw a line from the center point of the entry hole across the drum core to opposite flange. This line should be carried up on both of the flanges.

The second cross-over point is located 180° from the first and marked in the same manner. This point can be quickly located by wrapping a length of the unarmored conductor core around the full circumference of the drum barrel. Dividing this into two equal lengths, take one length (holding one end at the first chalk mark) and wrap it around the drum core. Then place a mark at the opposite end; it should be 180° from the first cross-over point.

Sometimes it is found helpful to add an additional chalk line parallel to each of the two cross-over lines. This line is positioned to show where "break" should finish. This line should be about 3" from the main cross-over line when spooling a 15/32" diameter cable and proportionately less for smaller cables.

Calculating first layer on drum

The next step is to determine how many turns of cable will be needed for the first or bed layer to wrap around the core and fill the area between flanges. It is suggested that the cable diameter be divided into the measurement between flanges; thus, if using a .200" O.D. cable with 20" between flanges, 100 turns would be required to fill the drum.

This method should work well within a half turn. If slightly more or less is required, add or remove a half turn. Judgment must be used in an effort not to disturb the bed layer any more than needed. Generally, cables will spool, or thread lay, easier if a half turn is removed than when an extra half turn is added.

After the required number of turns is determined, the cable end is inserted through the entry hole near the side of the flange where it is properly tied down and prepared for connection to the collector ring. The drum is then rotated to add three or four turns. Just enough back tension is used to hold cable in place.

Beginning installation

Using a hammer (Blacksmith) and dull nosed (3") chisel, work the cable away (rom the flange (starting at the break point 180° from the entry hole, continuing around to the entry hole) and insert the first length of packing material between the flange and the cable. The packing material (approximately 1/2 diameter of cable) is fitted into place with the hammer and chisel as the drum rotates slowly with all turns being moved into proper position. (Generally, the unarmored conductor core can be used as packing material.)

After the first length of packing has been inserted, continue to rotate the drum, adding the balance of cable required for the bed layer, (see fig. 11)

Correct back tension

Back tension is very important from this point on. Generally, just enough tension is used on the bed layer to obtain the required number of turns. Using too much tension will cause the cable to oval and not allow the required number of turns to fit between the flanges. Normal tension on the first layer would be approximately 10-15% of the breaking strength of the cable. On a 7/32" cable, we suggest using 400 lbs, and 1,500 lbs. on a 5/16" cable, (see table for suggested tensions and fig. 3.)

Installing second and third layers

Before adding the last turn to fill the drum on the first layer, the decision must be made as where the second length of packing material should be placed. If no additional turns appear to be needed, the second packing should be Inserted in the 0° to 180° position or on the opposite bottom side from the first packing. If an additional half wrap is required, it should be inserted (using hammer and chisel to evenly move cable turns closer together) in the l80° - 360° position or directly across (top) from the first packing.

With the drum, again rotating slowly, the tension should be increased to approximately 15 to 20% of the cable's rated breaking strength to add the second layer.

After the second layer has bean added, again check for proper fleet angle. This may require movement of equipment to obtain correct position. Slight adjustments, using hammer and chisel, may also be required to help develop proper cross-over points.

During application of the third layer, the tension should be increased to approximately 20-25% of breaking strength. At the end of the third layer, fleet angle and break points should again be checked and any slight adjustments made.

Completion of spooling/points to watch

From this point on, as each layer is added, the "break" points should move back slightly. This can be checked with the chalk marks located on the side of the flanges. If the "break" line moves back too quickly, it means there are too many turns in bed layer.

Should the "break" line move forward very quickly, it means there are not enough turns in bed layer. This also causes large spaces between cable turns, which allows the cable to "crack out" or develop "low spots."

Should the outside diameter of the cable vary, it should be compensated for by adding or removing turns in the bed layer. Slight adjustments in the back tension may also be needed to adjust for minor O.D. changes and overall cable condition.

Good spooling can be obtained if the equipment is in good condition and properly handled. Working with the known O.D. of the cable plus proper handling of back tension and fleet angle, will generally insure good thread lay spooling with a minimum of effort.

The foregoing information is intended only as a "standard guide" for normal hoisting conditions. It is not intended to cover every detail nor satisfy every operating condition. Many special services, such as deviated and extremely deep hole work, may require some modification of these procedures to suit the special conditions.

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Camesa, Inc · 1615 Spur 529 · P.O. Box 1048 · Rosenberg, Texas 77471 Phone: (281) 342-4494 · Fax: (281) 342-0531