Contact Us Pole Products Newsroom Mission

1. Does your system include virtually inaccessible, aging back lot distribution lines?

• Pole installation has to be done by hand, lighter weight composite reinforced composite (FRC) has the advantage over wood. The jobs go faster and with less manpower. In many inaccessible locations, FRC is the only practical choice.

• Composite poles are totally immune to the ground line deterioration that haunts wood.

• Composite poles can be manufactured in the color of the homeowners association's choice, making a much more attractive installation than wood.

• In over 30 years experience with FRC lighting poles, we haven't found a woodpecker in one yet.

• Composite poles are manufactured from environmentally friendly materials. There are no toxic preservatives to leach out into the soil or water around the pole. Since they are classified as safe, disposal of a composite pole is easier than a wood pole which is now classified as hazardous waste in some areas. We can go you one better than that. Shakespeare will take back destroyed poles and recycle them.

• Consider the hourly cost of a large helicopter. Now think how much you can save by using a smaller bird. Montana Power can attest to that.

• You can get that replacement pole through Mrs. Brown's immaculate flower garden without leaving tire tracks, how much can you save in landscaping repair?

WEIGHT COMPARISON OF COMPOSITE AND WOOD POLES

COMPOSITE UTILITY POLE STIFFNESS

COMPOSITE UTILITY POLE MANUFACTURING

These new fiberglass reinforced composite utility poles are manufactured using the filament winding process. There are other methods that can be utilized to form a hollow cylindrical structure. However, filament winding combines an economy of material and flexibility of material placement which make it the clear choice for this type of structure.

Filament winding is accomplished on a machine which winds glass fibers onto a mandrel in a prescribed pattern to form the desired finished shape. A programmable logic controller (PLC) is used in a closed loop control circuit to control machine movements. This system allows for placement of the right amount of fiberglass at the right place and orientation.

For filament winding, fiberglass is purchased in a yarn-like form called roving. This roving is routed through a bath of liquid, catalyzed, pigmented, polyester resin before it reaches the mandrel. After the fiberglass and resin are in place, a surface of resin impregnated non-woven polyester fabric is applied. Heat is then applied to initiate cross linking (hardening) of the resin. After hardening, the tube is removed from the mandrel. In this case, hydraulic cylinders with appropriate attachments push the tube off the mandrel.

After the tube is removed from the mandrel, it is trimmed to length and any required holes are drilled. If attachments for climbing steps are specified, they are installed at this time. The final step is the application of a pigmented polyurethane topcoat.

SPECIFYING COMPOSITE UTILITY POLES

SELECTING A SHAKESPEARE FRC UTILITY POLE

1. ROT OR DECAY
2. INCONSISTENCY FROM ONE POLE TO THE NEXT

SHAKESPEARE FRC UTILITY POLE OVERLOAD CAPACITY FACTORS

SHAKESPEARE CLASS 1 THROUGH CLASS 6 POLES ARE EXACTLY THE SAME, STRENGTH WISE, AS ANSI O5.1 REQUIRES OF THE WOOD POLE; I.E. , A CLASS 1 POLE HAS A CANTILEVER STRENGTH OF 4500 LB., AND SO ON, DOWN THE LINE. The required strength for these poles has been taken from ANSI O5.1 as listed in the appendix of the 1972 edition of O5.1 and restated in Annex B of the 1992 edition.

A very important difference is that the physical dimensions of the various species of wood poles were derived from the average strength of the species. AVERAGEMINIMUM strength is equal to the class rating. means that not all wood poles will make it to the strength level of its class. This is another reason for the very conservative overload factors used for wood. 

UTILITY POLE CLASS AND STRENGTH

This comparison can best be accomplished by comparing the ultimate bending moment capacities at various stations along the length of wood poles to the capacity of the FRC poles. For comparison, listed below are the values for the southern yellow pine class 4 40 ft. pole and the values for the Shakespeare FRC class 4 40 ft. pole. The ANSI strength level for class 4 is 2400 lb.

That 79.3 is a test load of 2478 lb. and 78.7 equates to 2459 lb. Also, the wood pole data is based on the average strength of southern yellow pine at 8000 psi while the FRC data is based on the minimum strength Shakespeare has observed after many years of testing at 25000 psi.

• Remember, a Shakespeare Composite Structures class 4 Tuff-Pole® has a minimum strength of 2400 lb. while some of the class 4 wood poles will not even reach 2400 because average data was used to establish the fiber stress figures in table 1 of ANSI O5.1.

SHAKESPEARE COMPOSITE STRUCTURES™ FRC UTILITY POLE COLUMN LOADING

[See printed report for equation - Webmaster]

Since [x], 4, and L are the same for both wood and FRC, it follows that, for two poles of the same length, the column strength is proportional to the product EI. We have computed these values for both wood poles and the FRC poles. In Appendix B you will find plots of this value vs. height above ground. You will note that the FRC pole is stiffer than the wood pole in most cases, and the differential is small in the others.

SHAKESPEARE FRC UTILITY POLE STRENGTH VERIFICATION

Appendix E contains several test reports for various lengths and classes, as well as the results of tests performed by Engineering Data Management in Ft Collins, Colorado, for Shakespeare and Montana Power. Our plant safety officer required that all personnel move back to a safe distance after 1000 lb. was reached. We are in the process of setting up a computer controlled data acquisition system which will automatically record load vs. deflection without endangering the test crew. In the EDM test report, you will note that the load-deflection curve is essentially a straight line, so deflection readings in the 0 to 1000 pound range can be used to project the deflection at higher loads. The same can be said of the test data accumulated at Shakespeare.

Appendix F is a plot of load vs. deflection data for a study we performed at glass wind angles from 15 to 45 . You can see how the angle of the glass filaments affects the flexibility of the pole. You can also see that the plot is a straight line for the 15 case. The load vs. deflection curve for a Shakespeare filament wound pole will always be a straight line because the wind angle of the helical layers is 10 to 15 .

In the near future we will be able to record deflections to failure regardless of the load.

TOP AND BUTT CAPS

MOUNTING CROSSARMS, DOWN GUYS, TRANSFORMERS, ETC.

THROUGH BOLT TORQUE INTEGRITY

SHAKESPEARE FRC POLE STRENGTH AT ATTACHMENT BOLTS

Shakespeare has performed pull through tests on 5/8" bolts using a single standard curved square washer under the head. The most severe of these located the bolt 12" from the tip of the pole and resulted in an ultimate load of 3600 pounds. At this point, the wall of the pole buckled in and bent the curved washer inside out. Appendix M.

The enclosed test report from EDM (Appendix E) also includes a loading test with a steel standoff bracket. From the bending moment at the base of the bracket we have calculated the load trying to pull the square washer through the pole at about 7300 lb. This bracket was located farther from the tip than the Shakespeare tests.

Additional tests were performed to determine if bolts loaded in shear will rip through the wall of the pole. Tests at Shakespeare indicate a load carrying ability of a 5/8" through bolt at 5000 lb. The vertical loading test performed by EDM at Colorado State University revealed negligible damage to the bolt hole after 3650 lb. (Appendices E and G;)

DRILLING

THROUGH BOLT MAXIMUM TORQUE

Testing performed by Shakespeare has led to a recommended torque of 50 ft.-lb. We have been told by contacts in the utility industry that this is about the amount that a lineman on the pole can apply with a typical wrench anyway. You may be aware that early prototypes were not suitable for more than 35 ft.-lb. Please note that this issue has been addressed and resolved.

Early testing of bolt tightening used short pieces of pole which did not exhibit the full circumferential strength of the pole. Torque tests have been rerun up to 150 ft-lb. Of course, at this torque the cross section of the pole is severely distorted, but there was no structural damage to the pole. Based on deformation of the pole, we now recommend a maximum torque for 5/8" bolts of 50 ft-lb. At this torque there is no visually discernible deformation of the pole. This distortion can be used by the linemen as an indicator of bolt torque. See the test report in Appendix H.

CLIMBING SHAKESPEARE FRC UTILITY POLES

STRENGTH

SECURITY

ATTACHING GROUND WIRES ETC.

Hardware commonly attached to wood poles with nails can be mounted on the composite poles with the same screws mentioned above.

SHAKESPEARE FRC UTILITY POLE UV LONGEVITY

The keys to long term surface life of FRC products exposed to UV are :

1. The immediate surface exposed to UV should be covered with a UV inhibited coating. Shakespeare uses a urethane coating with UV inhibitors. Appendix O contains a technical report on the longevity of the Shakespeare UV inhibited coating.
2. Before coating, the product should have a resin rich surface with UV inhibitors in the resin system. Shakespeare uses a specific ratio of glass to UV inhibited resin to obtain the required resin rich surface. This UV inhibited resin is used through the entire wall thickness.
   

Application of both of these steps gives normally in excess of 25 years before the surface begins to show signs of aging.

3. Shakespeare's application of a resin rich non woven polyester veil, combined with both items above, gives the ultimate extended life of eighty (80) plus years before blooming can occur.
   

After first installation, it is expected that FRC poles would have minor nicks and surface abrasions that are of no concern. If areas of the surface larger than about an inch square are damaged, these should be touched up with Shakespeare touch up coating.

• WHY AREN'T FRC AND WOOD POLES THE SAME DIAMETER?
This is a necessary design trade-off because it is more economical to gain strength and stiffness with a diameter increase than by increasing wall thickness.

SHAKESPEARE FRC UTILITY POLE ELECTRICAL PROPERTIES

Critical impulse flashover tests have been performed at the Georgia Power High Voltage Lab. The results are shown in Appendix N.

AVOIDING FIBERGLASS DUST IRRITATION DURING FIELD

FIBERGLASS DUST HEALTH ISSUES

Upon skin contact, those with sensitive skin can develop contact dermatitis. Treatment normally is a local application of hydrocortisone cream available at the local pharmacy.

For information on the effect of fiberglass dust on the lungs, please refer to the report included in Appendix K: "Health Considerations of Textile Fiberglass Used in Reinforcement Applications", Bender and Brandon, Ph.D.

ATTACHMENTS AND POLE WEIGHTS

SHAKESPEARE FRC UTILITY POLE AND RESONANT VIBRATION

Based on prior experience, it appears that the FRC poles would indeed act to damp vibrations induced by a conductor which has gone into resonance. Even so, vibrating conductors should be treated the same as when mounted on wood poles.

SHAKESPEARE FRC UTILITY POLE FATIGUE LIFE

We at Shakespeare, have not been able to induce any type of fatigue failure in a fiberglass laminate. About 15 years ago, Shakespeare performed some of the pioneer development work on fiberglass leaf springs for automotive applications. In a long term low frequency high stress fatigue test, a steel spring failed in fatigue at about one million cycles. An equivalent fiberglass spring with the same load and frequency applied, was cycled beyond two million cycles without failure.

Also, at about that same time, the question of fatigue came up concerning the electric utility brackets that were then in the Shakespeare product line. Deliberate attempts were made to induce fatigue failure on the vibration table in our test lab at moderate to high frequency. Even with sharp notches machined into the surface in an effort to initiate a crack, no fatigue failure occurred.

LIFTING AND SETTING SHAKESPEARE FRC UTILITY POLES

COMPOSITE UTILITY POLE STORAGE AND TRANSPORTATION

During storage, composite poles are not subject to decay, so contact with the ground will not structurally degrade the pole. Rainwater and minerals in the soil can stain the surface, however, so some means of supporting the stack off the ground is desirable. The height of the stack (therefore the weight of the stack) should be limited to avoid overloading the bottom layers. When step attachments are included, spacers should be provided to prevent damaging the surface of adjacent poles.

These strength results show that less material can be used and still meet the strength levels specified by the respective pole classifications. Therefore, the weights of these poles will decrease as this optimization progresses.