DEAS 322: 2023 
ICS 79.040  
 
© EAC 2023                                                                                                                       Second  Edition 2023  
 DRAFT EAST AFRICAN STANDARD  
Wood poles, cross -arms and blocks for power and telecommunication 
lines — Specification   
EAST AFRICAN COMMUNITY  
 DEAS 322: 2023 
ii © EAC 2023 – All rights reserved  
 Copyright notice  
This EAC document is copyright -protected by EAC. While the reproduction of this document by 
participants in the EAC standards development process is permitted without prior permission from EAC, 
neither this document nor any extract from it may be reproduced, stored or transmitted in any form for 
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Requests for permission to reproduce this document for the purpose of selling it should be addressed 
as shown below or to EAC’s member body in the country of the requester:  
© East African Community 2022  — All rights  reserved  
East African Community  
P.O. Box 1096 , 
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Tanzania  
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Fax: + 255 27 2162190  
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Reproduction for sales purposes may be subject to royalty payments or a licensing agreement.  
Violators may be prosecuted . DEAS 322: 2023 
© EAC 2023 – All rights  reserved  iii 
 Contents  Page 
Foreword  ................................ ................................ ................................ ................................ ............................  iv 
1 Scope  ................................ ................................ ................................ ................................ ......................  1 
2 Normative references  ................................ ................................ ................................ ............................  1 
3 Terms and definitions  ................................ ................................ ................................ ...........................  1 
4 Felling  ................................ ................................ ................................ ................................ .....................  6 
5 Materials requirements  ................................ ................................ ................................ .........................  6 
5.1 Species  ................................ ................................ ................................ ................................ ...................  6 
5.2 Grading  ................................ ................................ ................................ ................................ ...................  6 
5.2.1 Prohibited defects  ................................ ................................ ................................ ................................ . 6 
5.2.2  Permitted defects  ................................ ................................ ................................ ................................ .. 7 
5.2.3  Limited defects  ................................ ................................ ................................ ................................ ...... 7 
6 Dimensions and permitted tolerances  ................................ ................................ ..............................  14 
6.1 Size of poles  ................................ ................................ ................................ ................................ .........  14 
6.2 Diameters  ................................ ................................ ................................ ................................ .............  17 
6.3 Length  ................................ ................................ ................................ ................................ ...................  17 
6.4 Tolerances  ................................ ................................ ................................ ................................ ............  17 
6.5 Classification  ................................ ................................ ................................ ................................ ... 1817 
7 Manufacturing requirements  ................................ ................................ ................................ ..........  1817 
7.1 General  ................................ ................................ ................................ ................................ .............  1817 
7.2 Taper  ................................ ................................ ................................ ................................ .................  1817 
7.3 Cut of ends  ................................ ................................ ................................ ................................ ...........  18 
7.4 Trimming  ................................ ................................ ................................ ................................ ..............  18 
7.5 Shaving  ................................ ................................ ................................ ................................ .................  18 
7.6 Drilling  ................................ ................................ ................................ ................................ ..................  18 
8 Stacking and preparation of poles at depots  ................................ ................................ ...................  18 
9 Moisture content  ................................ ................................ ................................ ..............................  1918 
10 Poles preservation  ................................ ................................ ................................ ..........................  1918 
11 Marking and labelling  ................................ ................................ ................................ ..........................  19 
11.2   sampling  ................................ ................................ ................................ ................................ ..........  2120 
Annex  A (normative)  Stay -blocks and brace blocks  ................................ ................................ ...............  2322 
A.1 Materials requirements  ................................ ................................ ................................ ...................  2322 
A.2 Dimensions and  characteristics  ................................ ................................ ................................ .... 2322 
A.3 Preservative treatment  ................................ ................................ ................................ ....................  2322 
Annex  B (normative)  Bending strength (MOR) for poles and cross -arms  ................................ ............  2625 
B.1 Strength values for poles and cross -arms  ................................ ................................ ...................  2625 
B.2 Cantilever loading test for poles 6 m and longer  ................................ ................................ .........  2625 
B.2.1  Apparatus  ................................ ................................ ................................ ................................ .........  2625 
B.2.2  Procedure  ................................ ................................ ................................ ................................ .........  2625 
B.2.3  Calculation  ................................ ................................ ................................ ................................ ....... 2625 
B.3 Midpoint loading test for poles and cross -arms shorter than 6 m  ................................ .............  2726 
B.3.1  Apparatus  ................................ ................................ ................................ ................................ .........  2726 
B.3.2  Procedure  ................................ ................................ ................................ ................................ .........  2726 
B.3.3  Calculation  ................................ ................................ ................................ ................................ ....... 2827 
Bibliography  ................................ ................................ ................................ ................................ ..................  2928 
 DEAS 322: 2023 
iv © EAC 2023 – All rights reserved  
 Foreword  
Development of the East African Standar ds has been necessitated by the need for harmonizing requirements 
governing quality of products and services in the East African Community. It is envisaged that through 
harmonized standardization, trade barriers that are encountered when goods and services  are exchanged 
within the Community will be removed.  
The Community has established an East African Standards Committee  (EASC)  mandated to develop and 
issue East African Standards  (EAS) . The Committee is composed of representatives of the National 
Standard s Bodies in Partner States, together with the representatives from the public and private sector 
organizations  in the community .  
East African Standards are developed through  Technical Committees that are representative of key 
stakeholders including govern ment, academia, consumer groups, private sector and other interested parties. 
Draft East African Standards are circulated to stakeholders through the National Standards Bodies in the 
Partner States. The comments received are discussed and incorporated befo re finalization of standards, in 
accordance with the Principles and procedures for development of East African Standards.  
East African Standards are subject to review, to keep pace with technological advances. Users of the East 
African Standards are there fore expected to ensure that they always have the latest versions of the standards 
they are implementing .  
The committee responsible  for this document is Technical Committee EASC /TC 022, Wood, timber and their 
products , Subcommittee SC ##, [name of subcomm ittee] . 
Attention is drawn to the possibility that some of the elements of this document may be subject of patent 
rights. EAC shall not be held responsible for identifying any or all such patent rights.  
This second  edition cancels and replaces the first edition ( EAS 322:2002 ), which has been technically rev ised.  
 DEAS 322: 2023 
© EAC 2023 – All rights  reserved  v 
 Introduction  
The design and economic  use of wood poles , cross -arms  and blocks for the support of aerial communication 
and power lines  involves many factors including  fibre strength , growth charact eristics, freedom from decay 
and insect attack , seasoning and treatment.  
The fibre strength is affected by the extent of season ing the wood poles have receive,  and their freedom from 
decay and other defects are of importance in the determination of the mec hanical strength of the poles for 
assessing the safe loads in service.  
In this respect, the attention of pole users is drawn to the difficulty of defining and working to precise 
requirements on all aspects of a natural product such as timber. Some properti es have of necessity been 
specified in general terms only.   
It is therefore important  that the supervision of seasoning tests and of preservation processes and the 
acceptance of poles be assigned only to qualified and experienced inspectors.  
 DRAFT EAST AFRICAN STANDARD  DEAS 322: 2023 
 
© EAC 2022  – All rights reserved  1 
 Wood poles , cross -arms  and blocks for power and telecommunication 
lines —Specification  
1 Scope   
This Draft East African Standard specifies materials and performance requirements for solid wood poles , 
cross -arms and blocks for power and telecommunication lines .  
This standard applies to poles of simple cantilever members subject to transverse loads only.  
2 Normative references   
The following documents are referred to in the text in such a way that some or all of their content constitutes 
requirements of this document.  For dated references, only the edition cited applies. For undated references, 
the latest edition of the referenced document (including any amendments) applies.  
EAS 24, Glossary of terms used in timber industry  
EAS 124, Rounding off numerical values  
EAS 323 , Specification for wood preservation by means of pressure creosoting  
EAS 324, Copper/chromium/arsenic compositions for timber preservations — Methods of timber treatment  
3 Terms and definitions   
For the purposes of this document, the terms and definitions  given in EAS 24  apply . 
ISO and IEC maintain terminological databases for use in standardization at the following addresses:  
— ISO Online browsing platform: available at http://www.iso.org/obp  
3.1  
simple cantilever  
 
3.2  
average net retention (assay/sapwood zone)  
mass of all active components of a preservative compound retained in the zone of the treated pole and 
expressed in kilogram s per cubic metre  
3.3  
average net retention (total volume)  
mass of all active compon ents of a preservative compound retained in the total volume of poles treated 
together in one charge, and expresse d in kilograms per cubic metre  DEAS 322: 2023 
2 © EAC 2023 – All rights reserved  
 3.4 
batch 
group of poles offered at one time  
3.5  
boring  
process of extracting core samples from wood pole usin g an increment  borer or similar instrument  
3.6  
brace block or kicking block  
piece of treated wood buried in the ground t o support erected wood pole(s)  
3.7 
Theoretical Ground line (TGL)  
1.5m (plus or minus 25mm) from the butt end of the pole (unless otherw ise specified)  
3.8  
butt 
thick end of a pole  
3.9  
charge  
group of poles treated in one treating cycle  
3.10  
check  
lengthwise separation of the wood that usually extends across the rings of annual growth and commonly 
results from stresses s et-up in wood dur ing seasoning  
3.11 
crook  
natural curvature that extends over not more than 2m of the leng th of a pole  
3.12 
dead streak  
area, devoid (lacking) of bark resulting from progressive destruction of the growth cell of wood and bark at the 
edge of the streak. On a  pole, a dead streak is characterized by a discolored weathered appearance and by 
lack of evidence of overgrowth along the edges of the deadened surface.  
3.13  
debarking 
process of removing bark from the wood  
3.14 
decay  
decomposition of wood substance by fungi or other microorganisms resulting in softening, progressive loss of 
mass and strength. Fungal fruiting bodies or mycelium are evidence of decay.  
3.15 
defect  
characteristics or attributes of a wood pole which reduce compliance to the re quirement of th e specification  
3.16 
distribution of preservative/treatment chemical  
degree of spread of preservative/treatment chemicals in the wood pole.  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  3 
 3.17 
dressing  
process of preparing a wood pole to attain smoothness and un iform surface by removing barks and  branches, 
among others   
3.18 
drilling  
process of boring holes through the wood pole prior to treat ment for fixing pole headgears  
3.19 
drying  
process of reducing water content/moisture to the prescribed moisture content in the wood for effective 
preservative tre atment.  
3.20 
elliptical  
oval shape  
3.21 
fibre strength  
ultim ate stress of the wood fibres  
3.22   
fungal fruiting bodies/mycelium  
form of disfigurement caused by fungi which produce a powdery or wooly mycelial growth and masses of 
spores at the pole surfac e.  
3.23  
groundline  
one sixth of the pole len gth measured from the butt end  
3.24 
heartwood  
inner layer of the pole surrounded by the sapwood which in a living tree consists of dead cells and extractives 
and is generally dar ker than the sapwood in colour  
3.25 
hollow heart  
void in the heartwood ca used by decay or insect attack  
3.26 
hollow pith  
small hole at the pith centre of the pole caused  by disintegration of the pith  
3.27 
impregnation  
application of wood preservative into the pole by vacuum and pressure.   
3.28  
increment borer  
auger like instrument with a hollow bit, used to extract cores from wood.  
3.29  
inner bark  
physiol ogically active lay er of bark tissues in the wood  
3.30  
inspection  
examination of a wood pole to ensure conformity to the requirement  of the specification  DEAS 322: 2023 
4 © EAC 2023 – All rights reserved  
 3.31 
isokeraunic level  
average number of days per year when thunder can be heard in a given area.  
3.32  
kiln drying  
drying of poles within a controlled environment by the use of heated air in compartment or progressive ty pe 
kilns 
3.33   
knot  
portion of a branch or limb that has  become incorporated in a pole  
3.34 
mechanical damage  
defect caused  to a pole by mechanical means  
3.35  
minor/major axis  
shortest/longest diameter, respectively of any section of a pole (usually differentiated w hen measured  at an 
elliptical shaped pole)  
3.36 
Moisture Content (MC)  
amount of water contained in wood, usually expressed as a weight per centage of its oven -dry weight  
3.37 
outer bark  
layer of tissues (generally of a dry corky nature ) outside the vascular  cambium  
3.38  
penetration  
depth which the preservative has reached from the surface of the wood.  
3.39  
Pith 
small core in the stru ctural centre of the wood pole  
3.40 
pole girth  
circumference of the pole at any given point.  
3.41  
pole species  
scientific group of tree types suitable for use as poles.  
3.42  
preservation  
any process of chemical or physical treatment undertaken to extend the life of wood in service by increasing 
its resistance to deterioration.  
3.43  
preservative  
chemical or a mixture of ch emicals in a form suitable for application to poles in order to preserve them from 
damage ca used by wood destroying agents  
3.44  
red heart  
condition caused by fungus, Formes pin, which occurs in the living tree. Usually found in pine trees  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  5 
 3.44  
retention  
quantity of preservative i n a specified zone of the pole  
3.45  
sapwood  
outer layer of the pole (xylem) surrounding the heartwood which in a growing tree consists of living cells and 
generally is lighter in colour.  
3.46 
Scar  
result of injury to the living  tree which has begun to compartmentalize and a sign that the injury is being 
contained.  
3.47  
shake/ring shake  
separation along the grain, the greater part of which occurs between the rings of annu al growth  
3.48  
sound knot  
knot that is solid across the face in spite of having surface checks, and of which the fibres are so completely 
intergrown with the surrounding wood that it can be relied upon to retain its position in the wood.  
3.49  
spiral grain  
twist of grain in the pole or the wood in which the fi bres take a spiral course about the trunk of the tree  instead 
of the vertical course  
3.50  
splinter pull  
formation of hollows in normal wood at the butt of a pole, caused by long needle like splinters during felling.  
3.51  
Split  
lengthwise/longitudinal se paration of the wood extending completely through the piece from one surface to 
another.  
3.52  
Stain (sap stain)  
discoloration of the sapwood, caused by the action of certain molds and fungi which is not accompanied by 
softening or other disintegration of  the wood. Usually found in pine trees.  
3.53 
Stay block  
treated piece of wood buried in the ground to support a stay wire connected to and erected wood pole.  
3.54  
Sweep  
natural curvature that extends over more than 2m of the length of a pole.  
3.55  
Tape r 
longitudinal gradual decrease in diameter as you move from the butt end to the top of the pole.  
3.56 
Turpentine  
fluid obtained by the distillation of resin obtained from live trees.  DEAS 322: 2023 
6 © EAC 2023 – All rights reserved  
 3.57  
Turpentine acid face scars  
area in the lower portion of the pole  where bark hack removal with acid applied has caused resin to flow.  
3.58  
Turpentine cat face scars  
depression in the surface of a pole resulting from the wood hack into the sap wood where the tree has not 
compartmentalized the wound and re - established the normal cross section of the pole.  
3.59 
Wood density  
ratio of wood  oven -dry weight to its volume  
3.60 
Wood natural defects  
features which develop during tree growth making wood less suitable for a particular purpose.  
4 Felling  
4.1 Trees shall be  felled  not more than 15 cm  to the ground as possible and no timber shall be removed, 
trimmed or cut from the butt end so as to reduce its natural size. The ends shall be sawn to give a flat section 
and branches shall be dressed down flush with the trunk. Bark sh all be removed as soon as practicable after 
felling except for eucalyptus, which requires a longer seasoning time.  
4.2 Rotation age for harvesting Eucalyptus trees for utility poles shall be at least eight (8) years . All trees for 
poles shall be felled pro perly and at a controlled speed in order to avoid mechanical damages.  All Eucalyptus 
trees for poles  should be debarked immediately after felling.  
5 Materials requirements  
5.1 Species  
5.1.1  Poles shall be made from species  that meet the requirements for power and telecommunication  poles . 
Common species are given in Annex… C 
5.1.2  When tested, after all machining has been completed, in accordance with either B.1 or B.2, each  pole 
and cross -arm shall be capable of withstanding, without showing any signs of fai lure, a force F calculated in 
accordance with the appropriate formula given in Annex B. The force F corresponds to a minimum fibre stress 
(in bending) of 55 MPa.   
5.1.3  Other species apart from those listed listed under Annex … may be used as long as they m eet the 
requirements of this standard.  
5.2 Grading   
5.2.1 Prohibited defects  
a) Cross -breaks (cracks);  
b) Decay, except as permitted for firm red heart in 5.2.2(a), defective butts in 5.2.3(d) and  decayed knots 
in 5.2.3(f);  
c) Dead streaks, except as permitted in 5 .2.3(f);  
d) Hollow butts or tops, except as permitted under hollow pith centers;  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  7 
 e) Marine borer damage;  
f) Holes, open or plugged, except holes for test purposes, which shall be plugged;  
g) Nails, spikes and other metal not specifically authorized by the purchaser  
h)  elliptical poles shall not be accepted  
 
 
Figure — Typical s ection of an elliptical pole  
5.2.2  Permitted defects  
a) Firm red heart — Firm red heart not accompanied by softening or other disintegration (decay) of the 
wood is permitte d; 
b) Hollow pith centres — Hollow pith centres in the tops or butts and in knots are permitted in poles that 
are to be given full -length treatment ; 
c) Sapstain — Sapstain that is not accompanied by softening or other disintegration (decay) of the wood 
is permit ted; and  
d) Scars — Turpentine acid face scars are permitted anywhere on the pole surface.  
 
Figure — Sap stain (Pine)  
5.2.3  Limited defects  
a) Bark inclusions — Depressions containing bark inclusions shall be not more than 50 mm in depth 
measured from the surface of the pole ; 
b) Compression  wood — The outer 25 mm of all poles shal l be free from compression wood visible on 
either end ; 
c) Dead streaks — A single, sound dead streak is permitted in East African pencil cedar, provided  the 
greates t width of the streak is less than 25 % of the circumference of the pole at the point of  
measurement ; and  
d) Defective butts — Hollowing in the butt caused by “splinter pulling” in felling the tree is permitted, 
provided that the area of such hollow is less t han 10 % of the butt area. Also hollow  heart does not 
DEAS 322: 2023 
8 © EAC 2023 – All rights reserved  
 occur closer than 50 mm to the side surface and provided that the depth of the  hollow does not 
exceed 600 mm, measured from the butt surface.  
e) Insect damage — Insect damage, consisting of holes 1.5 mm or  less in diameter, or surface scoring 
or channeling is permitted provided there is no active infestation and the strength of the pole is not 
affected by the degree of damage. Specifically, the following shall be permitted:  
i. Scoring or channeling (or both), of depth not exceeding 3 mm, on the surface of a pole.  
ii. Not more than five bark borer holes in any 1 m length of a pole provided that the holes are tightly 
plugged (after treatment) with an acceptable treated wood dowel.  
iii. Not more than 20 pinhole borer holes , in any 1 m length of a pole.  
 
f) Knots  
Sound knot  
Individual knots with diameters < 1/6  of the pole girth at that point. The sum of diameters of sound knots in the 
worst 150 mm of pole should be <1/3 of the pole girth at that  point . 
 
Unsound Knot  
Dead Knot: unsound knot containing a dead  
 
Dead Knot: knot in which its fibres are only partly intergrown (≤ 75%) with those of the surrounding wood and 
that sometimes includes b ark. 
Decayed knot: unsound knot containing a decay  
DEAS 322: 2023 
© EAC 2023 – All rights  reserved  9 
  
The allowable diameter of any unsound or combined diameters of a group of unsound knots (decayed and 
dead knots) shall not exceed one half of the allowances given for sound kno ts. 
NOTE  The limitations of knots are based on past practice and satisfactory performance.  
a) Scars (cat face) — No pole shall have a scar or turpentine ca t face located within 600 mm of the 
groundline. Other sound scars are permitted elsewhere on the pole su rface, provided they  are 
smoothly trimmed and do not interfere with the cutting of any grain, and provided that : 
i. the circumference at any point on trimmed surface loca ted between the butt and 600 mm below 
the groundline is not less than the minimum circumf erence specified at 1.5 m from  the butt for 
the class and length of the pole (see Table 1 and Table 2) ; and 
ii. ii) the depth of the trimmed scar is not more than 50 mm, if the  diameter is 250 mm or less, or 
1/5 the pole diameter at the location of the scar if  the diameter is more than 250 mm.  
b) Shakes — Shakes in the butt surface which are not closer than 50 mm to the side surface of the pole 
are permitted, provided they do not extend to the groundline. Shakes or a combination of connected 
shakes which are close r than 50 mm to the side surface of the pole are permitted provided they do not 
extend further than 600 mm from the butt surface and do not have an opening wider than 3mm. 
Shakes in the top surface are permitted in poles that are to be given full length pr eservative treatment 
provided that the diameter of the shake is not greater than 50 % the diameter of the top of the pole.  
Sweep and crook Shall be permitted to the extent that a straight line from the center of the top to the 
centre of the pole at 1.5m fr om the butt remains within the pole.  
DEAS 322: 2023 
10 © EAC 2023 – All rights reserved  
 
 
Figure 1 — Measurement of sweep in one plane and one direction  
c) Slope of grain — Spiral grain shall not exceed a slope of 1 in 6.  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  11 
  
d) Splits & checks   
In the top  
A split or a combination of two single checks (each check terminating at the pith center and separated by not 
less than 1/6 of the circumference) having one or both portions located in a vertical plane within 30 
degrees of the top bolt hole shall not extend downward along the pole mo re than 6 inches (15cm). All 
other combinations of checks or a split shall not extend downward along the pole more than 12 inches 
(0.31 m).  
In the butt  
A split or a combination of two single checks, as defined above, shall not extend upward along the pole  more 
than 2 feet (0.61 m).  
 
Table 1 — Maximum permissible defects  
1 2 3 
Description of defect  Permissible maximum  
Poles  Cross -arms  
 Checks    
 a) End checks    
1) Number a   
 Top 4 3 
 Butt 4 3 
2) Length (as it appears on  the surface)    
DEAS 322: 2023 
12 © EAC 2023 – All rights reserved  
  Top 2 x top dia.  2 x top dia.  
 Butt 5 x butt dia.  2 x butt dia.  
3) Width    
 i) Top    
 If top dia. does not exceed 180 mm:  1/10 dia. or 15 mm 
(whichever is 
less)  6mm  
 
 If top dia. exceeds 180 mm:  1/10 dia. or 15 mm 
(whichever is 
less)  10 mm  
 
 ii) Butt    
 If top dia. does not exceed 180 mm:    
 Individual width  1/10 dia. or 25 mm 
(whichever is 
less)  1/10 dia. or 10 mm 
(whichever is 
less)  
 Sum of widths  50mm  - 
 If top dia. exceeds 180 mm:    
 Individual width  1/10 dia. or 25 mm 
(whic hever is 
less)  1/10 dia. or 15 mm 
(whichever is 
less)  
 Sum of widths  50mm  - 
 b) Surface checks    
1) Number b 3 at any cross section  3 at any cross section  
2) Individual length  8 x dia. c 8 x dia.c 
3) Individual width  15 mm  10mm  
4) Sum of widths  40 mm  25mm  
a End checks that extend through the centre of an end and appear in two opposite positions of the 
periphery are regarded as two checks.  
b Provided that where three checks occur together at any cross section, the sum of their lengths shall 
not exceed  half the length of the pole or cross -arm. 
c The diameter of the pole or cross -arm midway along the length of the check.  
 
The wood poles shall be prevented from cracking or splitting at the top and butt by using galvanized round 
Gang nails which covers no t less than 65% of the total area of the pole ends surface as shown on Figure 
below. Gang nails shall be able to penetrate not less than 14 mm and galvanized to at least 47μm. In addition 
to the gang nails, the manufacturer may use spiral binding to preven t any splitting or cracking of the pole.  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  13 
  
 
 
m) Splinter pull  
n) Pole length  
o)Taper  
p) Mechanical damages  
l) Sapwood thickness  
Thickness of sapwood should be at least 15 mm. 
 
m)Splinter pull  
Defective butt from splinter pulling  provided the area of the hollow is < 10% of the butt area.  
DEAS 322: 2023 
14 © EAC 2023 – All rights reserved  
  
n) Pole length  
Can be shorter by not more than 75mm or 150mm longer than the nominal length. At top of the pole, length is 
measured from the lower part of the slant cu t which should be 100.  
 
o) Taper  
Taper shall not exceed 10mm per m.  
 
p) Mechanical damages  
Damages are not allowed except when:  
i. The depth of the damage is not more than 3mm and;  
ii. The length of t he damage is less than 300mm and;  
iii. The width of the damage is less than 25mm.  
 
6 Dimensions and permitted tolerances  
6.1 Size of poles  
DEAS 322: 2023 
© EAC 2023 – All rights  reserved  15 
 Table — Dimension of poles  
Length  Minimum top 
diameter  Minimum diameter at 
theoretical Ground 
line Minimum testing force  
Cantilever loading  
m mm mm kN (kgf) 
1.5 80    
1.5 100    
1.5 120    
1.5 140    
1.5 160    
2 80 82.5 7.57 771.93  
2 100 102.5  14.52  1480.63  
2 120 122.5  24.78  2526.86  
2 140 142.5  39.01  3977.91  
2 160 162.5  57.84  5898.04 
2.5 80 85 3.68 375.26  
2.5 100 105 6.94 707.68  
2.5 120 125 11.7 1193.07  
2.5 140 145 18.27  1863.02  
2.5 160 165 26.91  2744.06  
3 100 107.5  4.78 487.42  
3 120 127.5  7.98 813.73  
3 140 147.5  12.36  1260.37  
3 160 167.5  18.1 1845.69  
3 180 187.5  25.39  2589.06  
3.5 100 110 3.78 385.45  
3.5 120 130 6.24 636.30  
3.5 140 150 9.58 976.89  
3.5 160 170 13.94  1421.48  
4.5 100 115 2.83 288.58  
4.5 120 135 4.57 466.01  
4.5 140 155 6.92 705.64  
4.5 160 175 9.97 1016.66  
4.5 180 195 13.79  1406.19  
6 80 102.5  1.49 151.94 
6 100 122.5  2.54 259.01  
6 120 142.5  4 407.89  
6 140 162.5  5.93 604.69  
6 160 182.5  8.4 856.56  
6 180 202.5  11.48  1170.63  DEAS 322: 2023 
16 © EAC 2023 – All rights reserved  
 7 80 107.5  1.37 139.70  
7 100 127.5  2.28 232.50  
7 120 147.5  3.53 359.96  
7 140 167.5  5.17 527.19  
7 160 187.5  7.25 739.29  
7 180 207.5  9.83 1002.38  
8 80 112.5  1.3 132.56  
8 100 132.5  2.13 217.20  
8 120 152.5  3.24 330.39  
8 140 172.5  4.69 478.25  
8 160 192.5  6.52 664.85  
8 180 212.5  8.77 894.29  
9 120 157.5  3.05 311.01  
9 130 168 4.05 412.99  
9 140 177.5  4.37 445.62  
9 150 188 5.67 578.18  
9 160 197.5  6.02 613.87  
9 180 217.5  8.04 819.85  
10 130 173 3.86 393.61  
10 140 182.5  4.15 423.18  
10 155 198 5.79 590.42  
10 160 202.5  5.67 578.18  
10 180 222.5  7.52 766.83  
10 200 242.5  9.73 992.18  
11 140 187.5  3.99 406.87  
11 160 207.5  5.41 551.67  
11 180 227.5  7.13 727.06  
11 200 247.5  9.19 937.12  
11 210 258 11.37  1159.42  
11 220 267.5  11.6 1182.87  
12 140 192.5  3.89 396.67  
12 160 212.5  5.23 533.31  
12 180 232.5  6.85 698.51  
12 185 238 8.02 817.81  
12 200 252.5  8.77 894.29  
12 210 263 10.82 1103.33  
12 220 272.5  11.02  1123.73  
13 140 197.5  3.81 388.51  
13 160 217.5  5.09 519.04  
13 165 223 5.99 610.81  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  17 
 13 180 237.5  6.63 676.07  
13 190 248 8.24 840.25  
13 200 257.5  8.45 861.66  
13 215 273 11.00  1121.69  
13 220 277.5  10.57  1077.84  
14 160 222.5 4.99 508.84  
14 180 242.5  6.46 658.74  
14 200 262.5  8.2 836.17  
14 215 278 10.64  1084.98  
14 220 282.5  10.22  1042.15  
15 160 227.5  4.92 501.70  
15 180 247.5  6.34 646.50  
15 200 267.5  8 815.77  
15 220 288 10.91  1112.51  
16 160 232.5  4.88 497.62  
16 180 252.5 6.24 636.30  
16 200 272.5  7.85 800.48  
16 220 292.5  9.71 990.14  
17 225 303 11.00  1121.69  
18 160 242.5  4.84 493.54  
18 180 262.5  6.13 625.09  
18 200 282.5  7.65 780.08  
18 225 308 10.82  1103.33  
 
This East African Standard shall be applicable to prefe rred dressed sizes of poles as given in Table 1 . 
NOTE  All circumferences and diameters are applicable to debarked and seasoned or dry poles.  
6.2 Diameters  
Many nominally round poles have a natural elliptical cross section; the diameter measurements of such  poles 
shall be of the minor axes . 
6.3 Length  
Length shall be measured between the extreme ends of the pole or in case of a pole with a sweep (see 
5.2.3(i)); length shall be measured to the short end of the slope.  
6.4 Tolerances  
Poles shall be not more th an 75 mm shorter or 150 mm longer than the nominal length (see 7.2).  DEAS 322: 2023 
18 © EAC 2023 – All rights reserved  
 6.5 Classification  
The true diameter class shall be determined by measuring the diameter at 1.5 m from the butt end. This 
dimension will determine the true class of a pole, provided that its top diameter (measured at the minimum 
length point) is large enough.  
7 Manufacturing requirements  
7.1 General  
Outer bark shall be removed from all poles and inner bark shall not be permitted. All poles shall be round with 
no excessive removal of the sa pwood.  
7.2 Taper  
The taper in a pole from top to the butt shall not exceed 10 mm per meter of the length of a pole.  
7.3 Cut of ends  
The butts of the poles shall be cut perpendicular to the central axis with a tolerance of 50 mm across the sawn 
surface. The top of the pole shall be slant cut with a 10° - 30° slope.  
7.4 Trimming  
Knots on the pole surface, whether partially or fully grown and branc h stubs shall be trimmed close. Trimming 
may be done by  hand tools . 
7.5 Shaving  
If shaving is used, the depth of cu t shall not be more than necessary to remove inner bark and to trim all 
branch stubs and overgrown knots smoothly and closely. There shall be no abrupt change in the contour  of 
the pole surface between the groundline and the above ground sections. The lowe r 600 mm pole section may  
be trimmed to remove wood fibres causing butt flare, provided sufficient sapwood remains to obtain the 
minimum penetration requirements.  
No sapwood shall be removed from the butt of the pole to 1 m above proposed ground level, the  minimum 
sapwood thickness being 25 mm. The remainder of the pole should be trimmed to produce a rounded pole 
while maintaining a minimum sapwood thickness of 20 mm.  
7.6 Drilling  
Where practicable, poles shall be delivered predrilled to suit the different types of pole duties and 
configurations. All drilling and fabrication shall be carried out before preservative treatment.  
The drilling configuration shall be as per the customer requirements.  
8 Stacking and preparation of poles at depots  
All poles shall be  stacked in open formation, before and after dressing, on suitable skids so that the lowest 
timber of each stack is at least 250 mm above the ground. Sufficient dunnage or cross -timbers shall be used 
to distribute the total mass without imposing under stra in on the poles at the lower layers. The surface of the 
seasoning ground under and around the stacks shall be well drained and kept free from bark, shavings, grass 
and weeds.  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  19 
 9 Moisture content  
9.1 Preservation of species shall not take place until the ave rage moisture content of each batch of the 
poles is reduced to not more than 25 %. No individual pole in the batch shall have a moisture content greater 
than 28 %. 
9.2 The moisture conten t of the poles shall be determined prior to treatment by the oven tes t method or any 
other suitable method in accordance with the method described in annex B of EAS 323.   
9.3 Poles for preservation shall be protected against heavy and continuous rain.  
10 Poles preservation  
10.1 The following species shall be pressure impre gnated with creosote in accordance with EAS 323 or with 
a copper/chromium/arsenic (CCA) mixture in accordance with EAS 324.  
 Red wood  
 Corsican pines  
 Douglas fir  
 Dunkeld larch  
 Lodgepole pine  
 East African pencil cedar  
 Eucalyptus  
10.2 When pressure impregnatin g in accordance with EAS 323, the coal tar creosote used shall comply with 
type 2 and the net retention of preservative in a charge shall be not less than 115 kg/m3  of the total volume . 
10.3 When pressure im pregnating in accordance with EAS 324, the copper /chromium/arsenic mixture shall 
have a solution strength not less than 5 % (m/v) and the sapwood  retention of preservatives in a charge shall 
be not less than 20 kg/m3 of active oxide sapwood . 
11 Marking and labelling  
11.1 Each pole shall have an Aluminium  or galvanized mild steel gouge name plate of at least 75mm long, 
55mm wide and 1mm thick placed at 1.8m from the ground line and shall be marked with characters not less 
than 3.5mm high, 3.5mm wide and gouged at most 0.25mm deep. Spacing between character s shall be 1mm 
and between words 2mm. Each name plate shall be attached by means of galvanized nails of at least 30mm 
in length and at least 2.5mm in diameter. the coatings on the galvanized mild steel tags shall comply with the 
requirements for class Z 27 5 of ISO 3575 and the coatings on the nails shall have a galvanizing thickness of 
at least 25 μm. The coded information shall include the following:  
a) Client name;  
b) Contract Number (Optional)  
c) Batch number (e.g. 01);  
d) Batch Size (Optional)  
e) Pole length in metres ; DEAS 322: 2023 
20 © EAC 2023 – All rights reserved  
 f) Pole top diameter in mm;  
g) Country of origin,  
Example  TZ for Tanzania, KE for Kenya, UG for Uganda, BU for Burundi, RW for Rwanda SS for South Sudan and 
DRC  for Democratic Republic of Congo , CMR for Cameroon . 
i). Speci es of the pole  
Example  EU for Eucalyptus,  where the species is known, it should be indicated for example, ES for Eucalyptus Saligna  
ii). Month  and Year of preservative treatment;  
Example  05/2023 
iii). Type of preservative treatment (e.g. CCA for Copper Chromium Arsenic); and  
iv). Name or Mark of Preserver/Manufa cturer.  
The layout of these markings is appended as Figure below.  
 
Figure 1: Required markings for wood poles  
Pole treated with creosote shall carry no other distinguishing mark. Appropriate letters shall denote other 
forms of preservation.  
Each pole shal l also have the pole length in metres and the pole class impressed on the pole butt  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  21 
 ‘For traceability any other method of poles marking may be used, e.g bar code and chips’  
11.2 Sampling  DEAS 322: 2023 
22 © EAC 2023 – All rights reserved  
 Table — Sample sizes  
1 2 3 4 5 
Lot size, poles, cross -arms 
or spac ers Sample for inspection  Sample for testing  
Sample size, 
poles, cross -arms 
or spacers  Acceptance 
number  Sample size, 
poles, cross -arms 
or spacers  Acceptance 
numbera 
50 450 20 2 8 0 
151 500 50 5 13 1 
501 1200  80 7 20 1 
1201  3200  125 10 32 2 
a Not ap plicable to the moisture content of poles  and cross -arms treated with a mixture of copper -chromium -arsenic 
compounds.  
 DEAS 322: 2023 
© EAC 2023 – All rights  reserved  23 
 Annex  A 
(normative)  
 
Stay -blocks and brace blocks   
A.1 Materials requirements  
Preferably stayblock and brace blocks shall be sourced fro m naturally durable species for example  Mninga 
(angolensis pterocarpus angolensis) or Mtundu (croton macrostachys) but species listed in 5.1 may be used 
with specified preservative treatment.  
A.2 Dimensions and characteristics  
The stayblocks and brace blo cks may be cut from sawn timber or f rom the round timber to produce 
rectangular, round or half round sections, whichever is economical, from the available material.  Stayblocks 
and brace blocks shall be in accordance with Figure 3 and figure 4 respectively;  and with the following 
requirements:  
A.2.1  The width of stayblocks and brace blocks shall be as near as p ossible to the dimension stated but 
must be within the range of 200 mm to 300 mm. If it is convenient to cut stayblocks and brace  blocks from 
larger s ize poles, then the side shall be cut as indicated in the figures to reduce the  maximum width. The 
longitudinally cut surfaces of stayblocks and brace blocks shall be straight and  clean -cut, while annual rings 
shall be approximately parallel to the wide fa ce. Planing is not required.  Wain is permitted on one face. The 
blocks shall be bored as indicated in Figures 3 and 4.  
A.2.2  These stayblocks and brace blocks have been designed for a minimum failing load and  resistance to 
uplift of 65 kN. Uplift calculati ons are based on installation of sand of density of 550  kg/m3, which is 
considered to be representative of average worst gr ound conditions, with a minimum angle between stay pole 
of 30°.  
A.3 Preservative treatment  
The blocks shall be treated by either coal  tar creosote in accordance with EAS 323 or  
copper/chromium/arsenic mixture in accordance with EAS 324 after fabrication using Bethel/Rueping  
processes.  DEAS 322: 2023 
24 © EAC 2023 – All rights reserved  
 
 
 
Figure 3 —Stay -blocks dimensions  
 DEAS 322: 2023 
© EAC 2023 – All rights  reserved  25 
 Figure 4 — Brace blocks dimensions  
 
Annex  B 
Standard or trade na me Scientific names  Other names  
 Eucalyptus grandis  River Red Gum  
Gum  Eucalyptus hybrid clones   
Iron Bark  Eucalyptus paniculata  Gum or Eucalyptus  
Spotted Gum  Eucalyptus citriodora (corymbia citiodora) or 
Eucalyptus maculata (corymbia maculata)  Lemon Sc ented Gum or Eucalyptus  
Tallow wood  Eucalyptus microcorys  Spotted Gum or eucalyptus blue gum  
Blue gum  Eucalyptus globulus   
Regnans saligna gum  Eucalyptus regnans  Giant Gum (mountain ash)  
 Eucalyptus saligna  Blue gum ( Saligna  gum)  
   
 Eucalyptus  cama ludensis  
Pinus sylvestris   
 
 DEAS 322: 2023 
26 © EAC 2023 – All rights reserved  
 Annex  B 
(normative)  
 
Bending strength (MOR) for poles and cross -arms  
B.1 Strength values for poles and cross -arms  
The mean bending strength of eucalyptus species specified in t his standard is 63 MPa.  
B.2 Cantilever loading test for poles 6 m and longer  
B.2.1  Apparatus  
B.2.1.1  Crib, capable of securing the pole under test from the butt end to the TGL, and that will  
a) ensure no significant movement of the clamped butt during a test;  and 
b) prevent any rotational movement of the pole.  
B.2.1.2  Wooden saddles, or similar suitable clamping devices (to secure the pole in the crib), of curvature 
that suits the diameter of the pole under test, and that will not damage the pole during the test.  
B.2.1.3  Winch, or similar device, of suitable capacity and preferably motor -driven, that is capable of 
applying force to the pole under test, the force being applied horizontally and at an average angle of 
approximately 90° to the pole, through a cable of  such a length that, during a test, the angle varies between 
slightly less than and slightly more than 90°.  
NOTE  The position of the crib relative to the winch has to be altered for varying lengths of poles under test.  
B.2.1.4  Force indicator or recorder, calibrated to indicate or record (as relevant), to within 2.5 %, the 
actual force applied to the pole.  
B.2.2  Procedure  
B.2.2.1  Using the wooden saddles, securely clamp the butt of the pole in the crib, over a distance of 1.5 
m ± 25 mm from the butt end. If  the pole displays crook or sweep, ensure that the concave side of the crook or 
sweep faces towards the winch. Secure the cable to the pole at a position 600 mm ± 25 mm or 100 mm ± 25 
mm, as relevant (see B.2.3), from the top end, and so position and secur e the crib or winch (or both), that the 
angle between the axis of the pole and the cable is slightly less than 90°.  
B.2.2.2  Take up the slack and, without jerking the pole, apply force (gradually and at as uniform a rate as 
possible) until the force reache s the appropriate value of F, calculated using the formula given in B.2.3. Then 
stop the test and release the force.  
B.2.2.3  Consider the pole to be defective if any visible sign of failure was noted during the test.  
B.2.3  Calculation  
Calculate the value o f F as follows:  DEAS 322: 2023 
© EAC 2023 – All rights  reserved  27 
 F = 
  
where  
F is the force, in newtons, required to cause a mean fibre stress in cantilever loading of 63 MPa;  
𝛔 is the mean fibre stress, i.e. 63 MPa;  
D is the minimum diameter, in millimetres, of the pole or cross -arm at the TGL (i.e. 1 500 mm from the 
butt end), based on the specified minimum top diameter and a taper of 5 mm per metre of length; 
and 
L1 is the distance, in millimetres, between the TGL and 600 mm from the top end in the case of poles 
and cross -arms of length at  least 6.0 m, and between the TGL and 100 mm from the top end in other 
cases.  
B.3 Midpoint loading test for poles and cross -arms shorter than 6 m  
B.3.1  Apparatus  
B.3.1.1  Two suitable anchorages, that : 
a) will not damage the pole/cross -arm during the test; and  
b) are such that the distance between them can be adjusted to the appropriate test span, i.e. the length 
of the pole/cross -arm under test, minus 600 mm or minus 200 mm, as relevant (see B.3.3).  
B.3.1.2  Suitable force applicator, that is positioned centrally between the anchorages, for example : 
a) either a hydraulic or a pneumatic ram of adequate capacity and stroke, that has a pressure foot of 
radius such as to fit the under test and that will not damage the pole/cross -arm during the test; or  
b) diameter at midleng th of the pole/cross -arm a suitable winch and cable.  
B.3.1.3 Force indicator or recorder , calibrated to indicate or record (as relevant), to within 2.5%, the actual force applied to the 
pole/cross -arm. 
B.3.2  Procedure  
B.3.2.1  So position the pole/cross -arm under test in the apparatus that the anchorages secure the 
pole/cross -arm at positions 300 mm ± 25 mm or 100 mm ± 25 mm (as relevant) from its ends and that, if the 
pole/cross -arm displays crook or sweep, the concave side of the crook/sweep faces towards the ram or the 
convex side of the crook/sweep faces towards the winch, as appropriate.  
B.3.2.2  If a winch and cable is used, take up the slack and, without jerking the pole/cross -arm, apply force 
to the midlength point of the pole/cross -arm. If a ram is us ed, extend the ram (without impacting the 
pole/cross -arm) until it touches the midlength point of the pole/cross -arm. In each case, increase the force 
(gradually and at as uniform a rate as possible) until it reaches the appropriate value of F, calculated using the 
formula given in B.3.3. Then stop the test and release the force.  
B.3.2.3  Consider the pole/cross -arm to be defective if any visible sign of failure was noted during the test.  
B.3.2.4  If the force is applied in any plane other than the horizontal  and vertical plane upward, a 
correction factor shall be applied to force F.  DEAS 322: 2023 
28 © EAC 2023 – All rights reserved  
 B.3.3  Calculation  
Calculate the value of F as follows  
 
where 
F is the force, in Newtons, required to cause a fibre stress in midpoint loading of 55 MPa or 75 MPa, as 
relevant;  
 is the relevant fibre stress, that is, 55 MPa or 75 MPa;  
D is the diameter of the pole or cross -arm at mid length point, in millimetres, bas ed on the specified 
minimum top diameter and a taper of 5 mm/m of length (see Table C.1);  and 
L2  is the distance, in millimetres, between 300 mm from the top end and 300 mm from the butt end in 
the case of poles and cross -arms of length at least 6 m, and between 100 mm from the top end and 
100 mm from the butt end in other cases . 
DEAS 322: 2023 
© EAC 2023 – All rights  reserved  29 
 Bibliography  
EAS 322:  2002 , Wood poles and blocks for power and telecommunication lines — Specification  
 DEAS 322: 2022    
 
© EAC 2022 – All rights reserved