Wood Pole Maintenance Manua Flashcards
What does pole need to be safe, reliable and econmial
It needs an effective program to detect and treat deteriorating poles before replacement becomes necessary.
What is a good method recommended to people who are unfamiliar with inspecting poles
Know your poles and to that take a new pole and a old one and split them in half and observe it history such how preservative worked on the old pole and if it had insect colonies and etc.
What’s inside the bark of a cedar tree
a zone of white sapwood surrounding a dark colored heartwood
Does sapwood varies depending on the species of the tree
Yes
What is the difference of red cedar and Douglas fir
Red cedar compared to Douglas fir its sap wood is less than inch thick compared to Doulgas fir which is increase 1 in small pole and 2 inch in a very large pole
What is the difference of Fast-growing tree and slow growing tree
Fast growing trees has deeper sapwood compare to slow growing trees
What is 90 percent of the tree made of
90% of trees is made of hollow fibers that are length wise along the tree stem. The fibers are 1/5 inch long. They are 100 time longer than wide
What is the 10 percent of the tree made of
The 10 percent that finish the tree structure is made of short, hollow brick shaped cells that originate from the bark of the bark toward the tree as ribbons or rays of unequal height and length
What is the environment that and weather that make sapwood deteriorate fast
Warm and moist soil make sapwood deteriorate fast
What are the species of tree that don’t have reliable hardwood
-Douglas Fir
-Western Larch
-Southern Yellow Pine
-Westerm Hemlock
-And others
What are the species of tree that have reliable Hard Wood
-Ceder
-Red Wood
And other species
What makes species with reliable Hard Wood different than with species that dont have strong hard wood
-They last 3 to 5 time longer
-Preservative makes their service life from 15 to 30 more years of service
example of high-density species and low-density species
- (HD) Douglas Fir
- (LW) Western Red Cedar
What make nondurable Heartwood tree more efficient that to use reliable Hardwood tree
nondurable trees are much more abundant
What is density in the aspect of tree species
Low density species of tree is more light weight than a high-density tree when its dry
low density has more void which hold more water
higher the density in a specified moisture content the stronger the wood is
At what location are trees denser and where are they less dense
Near the ground they are higher in density
At the top they are low in density
At what part of the tree contain more moisture
Sapwood of a tree contain more moisture because it conducts the nutrients from the roots to the leaves it stores water at the top of the tree where it has the most void (low dense) to water it leaves
note: heart wood doesn’t contain as much moisture
The effect of shrinkage and check how it happens
When a poles dry and season they only shrink when moisture content drops to 30 percent and below
-Wood shrinks more along than across the growth rings
-Small v check form in the surface of the wood
-As drying continues the check disappear and only a few deep check appear
-Deep checks in the center indicate a well season pole
small check is not a great indication of a dry pole
Wide narrow check indicates a well season pole
note: if the check becomes wide enough, they expose the untreated wood in which make the tree open to tree destroying organism
(ANSI 1972)
(American National Standards Institute)
Untreated poles
(AWPA)
American Wood-Preservers’ Association
Treated poles
How does preservative work on tree species
They penetrate the sapwood providing it a shell. If their moisture on the sapwood it makes much easier for the penetration of preservative to spread
Heart wood is much more are to penetrate with preservative, so it needs several slits 2 1/2 inches deep or perforated with rows of parallel holes expose the ends of the long wood fiber
another way to penetrated hardwood before the treatment saw a kerf to the center of the butt to five or more feet above the ground
What destroys the structural integrity of wood
Decay Fungai
What does fungai need to live
-It requires water, air, correct temperature, and food
What moisture does wood need to prevent Fungai
20%
(overdry basis)
What prevent Fungai growth
Air limits its growth when the wood is submerged in water or buried deep in the ground.
Freezing temperatures stops the growth and becomes seldom
80°F and decreasing as temperatures approach 100°F. Most fungi are killed at temperatures exceeding 150°F.
What promote Fungai growth
Temperature between 32°F and it peak 60°F fungai is active.
What are the bodies of fungai
Mushrooms and conks
How does Fungai reproduce
its produce with billions of microscopic seed-like structures called spores.
How do spore operate
spores germinate and produce hyphae, minute thread-like strands that penetrate throughout the wood. The hyphae secrete enzymes that dissolve the cellulose and lignin of wood into simpler chemicals that fungi can use as food.
How can you detect early signs of Fungai on wood
Early fungal attack on wood usually can be detected only by microscopic examination. During the early stages of decay, some fungi may discolor the wood or substantially weaken the wood, especially its toughness
What are the stages of the decay on wood
-wood becomes brash (breaks abruptly across the grain),
-loses luster and strength
-changes in color
Decay in advance stages is called what
rot
Brown rot
a brown, advanced decay that crumbles when dry, is common in most soft woods.
White-rot
fungi bleach or whiten wood in the advanced stage of decay, or they form small white pockets in rotted brown wood.
Soft-rot fungi
hat slowly cause an external softening of treated wood have extensively damaged poles below ground.
“dry rot”
this nomenclature is misleading because at one time the wood must have been wet enough to support fungal growth.
non-decay fungi
also inhabit wood, feeding on cell contents, certain components of cell walls, and the products of decay. Frequently only non-decay fungi can be isolated from rotted wood. Sapwood-staining fungi may reduce the toughness of severely discolored wood; other non-decay fungi gradually detoxify preservatives, preparing the way for decay fungi. Rapidly growing non-decay fungi frequently interfere with the culturing of the slower growing decay fungi.
Untreated poles
Poles rot in the sapwood right below the ground line where moisture and air are harmony for Fungai growth
once the Fungai is settle it extends several inches into the heartwood especially when there are seasonal checks
It doesn’t matter if the poles have 20% moisture aboveground it keeps rotting always as rainwater collects in the seasoning check
moist climates, poles with untreated sapwood above ground may have either surface rot or shell rot below the surface.
outer shell of solid wood, the hidden shell rot makes climbing hazardous for Electrical Workers.
Untreated poles or piles in fresh water deteriorate above the water line but not below where the oxygen supply is limited.
Decay pattern with relation to Douglas fir
it varies greatly for treated poles of Douglas fir with its low-durability heartwood and of cedar with its durable heartwood.
Decay relation to western red cedar
External rot can be cut off
Shell rot occurs frequently in moist climate in 12 to 15 years
Lost of thin sap wooed does decrease the strength of the pole
internal rot is found below or above the ground line and sometimes at the top of the pole
it has pocket of internal rot are nearly always clearly defined with a sharp demarcation between rot and sound, bright wood
depending on the water table cedar poles in dry soils can rot both externally and internally several feet below ground.
Decay relation of Doulgas fir
it varies greatly for treated poles of Douglas fir with its low-durability heartwood and of cedar with its durable heartwood.
pressure treated poles very rarely have external rot above ground and only infrequently have it below the ground line
the ground line zone should be checked periodically, especially on poles treated with new preservatives or processes
Internal rot is associated with checks that are below of or near the ground line, bolt holes, woodpecker holes, cut made during installation above ground, top of the pole is cut and is untreated an expose
Internal rot varies from small pocket or loss of central core
If a pocket of rot is detected, decay fungi can sometimes be cultured from much of the surrounding cross-section for several feet above and below the pocket. Usually no clear line separates sound (undecayed) and rotted wood in Douglas fir.
What are other wood inhabiting organism
Insects
woodpecker
marine boring animal
What is the most destructive organism wood face
Fungai
What are the insects that attack wood
Temites
Carpenter ants
beetles
What are termites
Termites work within wood with virtually no external evidence of their presence until the winged adults emerge and swarm in late summer and early fall. Then their wings, discarded for mating and starting new colonies, may indicate their presence.
sizes lengths vary from 1∕4 inch or less (subterranean and dry wood) to 3∕4 inch (damp wood), termites have bodies of fairly uniform width; the reproductives have wings of equal length.
What are Subterranean termites
are widespread and cause extensive damage, especially in southern states. Sure signs of their presence are the mud tunnels across treated wood or concrete that subterranean termites build from the ground where they nest to reach the untreated wood above. Damp wood termites inhabit moist wood in, on, or above the ground along the Pacific Coast. Dry wood termites feed on dry wood, primarily in the southern United States.
What are carpenter ants
They have restricted waist. the reproductive have wings. They don’t eat wood they just hollow it for shelter. Evidence of their existence is the saw dust made at the base of the pole. They are dark colored with a length of 3∕4 inch. They live in colonies
What are beetles
Buprestid is the most common in the Pacific Northwest. These metallic golden or green beetles, 3∕4 inch long, make an elliptical hole as the adults emerge from the pole to mate. Trained pole maintenance personnel recognize these elliptical holes as an indicator of internal rot often associated with attacks by the Buprestid beetle. Numerous emergence holes may indicate an unsafe pole.
Woodpeckers and their relations to poles
Woodpecker drum on poles as a mating ritual. They also us it a location for insect, store acorn and future food source.
they use heavy galvanized hardware cloth to seal the holes
Marine borers relations to poles
Shipworms are bivalves (mollusks) have small shell on their head. they burrow into the wood making a hole that can be 3/4 in diameter and 2 feet long
Gribbles, small crustaceans about 1∕10 inch long, tunnel in large numbers just below the surface of wood. Because waves break off the weakened surface layers of wood, gribbles gradually reduce the effective diameter of the wood.
Pentachlorophenol-treated wood should not be used in marine waters
Maine borers do more damage in southern latitude where special preservative is needed compared to northern latitude where pole is preserved with creosote
Where do marine borers ten to attack
coastal waters where salinity and oxygen supply are favorable.
What is Incipient Decay
Its form on untreated pole tops within one year. It reaches advance stage (rot) in 2 to 4 years.
What is the difference between the sound wood and decaying wood
Sound wood has a fibrous structure and splinters when broken across the grain, whereas rotted wood is brash and breaks abruptly across the grain or crumbles into small particles
What is the pick test
Lift a small sliver of wood with a pick or pocketknife and notice whether it splinters (sound) or breaks abruptly (rotten)
Shovel
scraper with triangular blade, or dull probe can be used to detect below ground rot on the pole surface. Cutting the blade of a shovel back several inches facilitates removal of earth around poles and from the surface of poles. If scraping exposes untreated wood, treat that area with a preservative solution or paste.
Hammer
use a lightweight hammer to feel the pole
you start from the top and make you eay down
Increment Borer (Bit, Handle, and Extractor)
its orgin is to measure tree growth but it can be use to extract wood core for examination and as well as of shell thickness and depth of preservative penetration
note: Cores can be retained and cultured for fungi.
Brace and Bit
A twist drill 3∕8 inch in diameter that is welded to an electrician’s bit or an extension rod of slightly smaller diameter permits rapid drilling into poles to well below the ground line. An abrupt decrease in drilling resistance indicates rot or a void. Wet wood, especially in cedar poles, and natural voids can falsely suggest rot. During the drilling process, examine wood particles to determine depth of the preservative and to note discolored wood and signs indicative of rot.
Shell-Thickness Indicator
Insert a metal rod and pole back if you feel resistance, it means its solid.
A shell-depth indicator detects rot in poles by “feeling” growth rings in sound, but not rotted, wood when inserted or removed from snug-fitting holes.
Power Auger
Poles can be inspected rapidly with an auger 1∕2 inch or more in diameter. Drilling resistance changes abruptly when the auger penetrates rotted wood. Chips can be examined.
Pol-Tek
It’s a sonic device develop by the Detroit Edison company. It starts 6 inches below the ground line it sends an echo made with a hammer if the dial is low compared to other reading it means its bad pole. It saves good pole from being drill
Shigometer®
It was developed to detect decay on live tree. it uses electrical resistance. Wood moisture need to be at or above 27%. which is typical of decaying wood or the ground line of poles. which is typical of decaying wood or the ground line of poles.
Moisture Meter
Resistance-type meters can be used to detect wood with a moisture content that exceeds 20%, the safe limit to prevent decay.
Inspecting Poles in Service
The time and extent of the pole line inspection will vary greatly depending on the inspector’s knowledge of the pole system.
intial pole inspection
it should be initiated bt digging to 18 inch deep will reveal surface decay in most areas, but you may have to dig deeper in dry areas where cedar poles can decay below the incised zone (about one foot above to three feet below the ground line).
Inspecting from The Ground
1 Condition of Pole Above Ground
2 Sounding
3 Drilling or Coring
4 Digging Inspection
5 Holes or Cuts Made During Inspection
6 Treating Excavated Poles
Treating Poles in Service
External supplemental treatments have long been used to successfully control surface decay in the outer one inch of poles. Only recently has internal decay of Douglas fir poles been successfully controlled by volatile toxicants. Depending on the condition of a pole, it may require an external treatment, an internal treatment, or both.
External Treatments
Above ground surface decay of cedar poles can be controlled by flooding the untreated sapwood with pentachlorophenol (usually 10%) in petroleum oil.
Below ground, bandage treatments minimize environmental contamination yet control surface decay by reinforcing the original preservative treatment. Water-soluble arsenicals and fluorides, alone or mixed with creosote or pentachlorophenol, diffuse into wet wood. They can be brushed on, injected 21∕2 inches into the wood through a needle at the end of a long lever, or incorporated on or in the wrap.
Internal Treatments with Water-Soluble Chemicals
Thick solutions of water-soluble chemicals or arsenicals and fluorides can be forced into voids in poles to diffuse through wet wood and control internal rot or insect damage.
Volatile liquids such as gasoline combined with creosote or pentachlorophenol have been successfully injected into voids to rid poles of ants.
Internal Treatments with Fumigants
Volatile chemicals “vapam, vorlex, and chloropicrin” effectively control internal decay of Douglas fir poles.
Reinforced Poles
Fumigants also are being used to stop decay in reinforced poles. Locate treating holes above the decay pocket and in solid wood to make sure that wood beneath the bands retains its strength. By stopping decay, fumigants eliminate the need for cutting off poles at the ground line. This way, the strength remaining in the poles can be utilized.
