drawings and specifications. You may be asked to submit information (fact-gathering package) on a new power distribution addition to the base. If so, the following recommended actions need to be considered:

Install utility poles in the same location, especially on upgrade projects.

Install power distribution systems underground whenever possible.

Conduct a survey using a map to chart the territory where the distribution lines are to be routed (for large areas, aerial photography is faster and more accurate).

Ensure that the survey map is large enough to clearly show all buildings. roads. streams, hills, ridges. railroads. bridges. and any existing power and communications lines.

Select the straightest and shortest route whenever possible.

Route the new distribution system near or in the general direction of future load demands.

Make the distribution system readily accessible for construction. inspection, and maintenance by paralleling them to existing streets and highways.

Avoid crossing hills. ridges, and swamp areas whenever possible to reduce the possibility of lightning and wind damage. These areas also increase costs because additional materials are needed and maintenance will be more difficult.

Coordinate with communication companies to prevent the induction of interference with their existing lines.

Select a route that is away from residential areas and does not damage the environment.

Keep major traffic routes free from primary, circuits. especially in nonindustrial areas.

Keep-distribution lines on the same side of the road whenever possible.

Avoid blocking driveways, entrances. exits. and fire escapes when installing branch lines or guys.

Locate poles 2 feet from the curb.

Finally. plan for future street-lighting circuits.

EQUIPMENT

Many different types and makes of overhead distribution equipment are in use today. This chapter will cover some of the standard equipment you will install and maintain, such as poles, transformers, capacitors, interrupting and protective devices.

Poles

Utility poles that support electrical lines must be designed to support the conductors, insulators, and shield conductors in a manner that provides adequate electrical clearances. A safe clearance must be maintained when the conductor temperature is elevated as a result of a large amount of current flowing in a circuit and also when the conductors are ice coated or strong winds are blowing.

The three most common types of poles that you will be working with are wood, reinforced concrete, and steel. Other types of poles in use are as follows: aluminum, fiber glass, and polysil. As a Seabee assigned to either a PWC or a battalion, you will be responsible for ordering, installing, and maintainingthe utility poles.

Power lines supported by wood-pole structures are generally considered to be the most economical. In the United States, the southern yellow pine, western red cedar, and the Douglas fir are the most commonly used species of tree. All wooden poles are given a preservative treatment (normally pressure treated) to prevent deterioration. The service life of the utility pole can be doubled by preservative treatment. Many of the older poles now in use were treated with creosote.

CAUTION

Creosote is a toxic compound that irritates the skin and sometimes causes blistering. It is also carcinogenic and is being phased out because of groundwater contamination problems. Used creosote contaminated poles may not be burned and must be disposed of in EPA approved landfills. You should use extra care when working around poles treated with creosote, avoid prolonged skin contact, and wash thoroughly after handling. Clothing contaminated with creosote should be laundered separately from family clothing.

Creosote oil, pentachlorophenol, and chromated copper arsenates have been used to provide a preservation treatment of wood poles. Newer poles are now treated with less toxic chemicals and, therefore, are safer to work with and also easier to climb (because the treatment softens the wood). They are environmentally acceptable because they do not contain materials that are toxic to mammals.