DRAFT UGANDA STANDARD  
  DUS EAS 322
First Edition
2010-mm-dd
 
Reference numbe r
DUS EAS 322: 2002
 © UNBS 2010
  
Wood poles and blocks for power and telecommunication lines 
— Specification 
 DUS EAS 322: 2002  
 
© UNBS  2010 – All rights reserved ii Compliance with this standard does not, of itself confer immunity from legal obligations 
A Uganda Standard does not purport to include all necessary provisions of a contract. Users are 
responsible for its correct application  
© UNBS 2010 
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilised in any 
form or by any means, electronic or mechanical, in cluding photocopying and microfilm, without prior written 
permission from UNBS. 
Requests for permission to reproduce this document should be addressed to 
The Executive Director 
Uganda National Bureau of Standards 
P.O. Box 6329 
Kampala  
Uganda 
Tel: 256 41 505 995 
Fax: 256 41 286 123 
E-mail: unbs@infocom.co.ug
Web: www.unbs.go.ug  
 DUS EAS 322: 2002 
© UNBS  2010 - All rights rese rved                iii National foreword 
Uganda National Bureau of Standards (UNBS) is a parastatal under the Ministry  of Tourism, Trade and 
Industry established under Cap 327, of the Laws of U ganda. UNBS is mandated to co-ordinate the elaboration 
of standards and is  
(a) a member of International Organisation for Standardisation (ISO) and  
(b) a contact point for the WHO/FAO Codex A limentarius Commission on Food Standards, and  
(c) the National Enquiry Point on TBT/SPS Agr eements of the World Trade Organisation (WTO). 
The work of preparing Uganda Standards is carried out through Technical Committees. A Technical 
Committee is established to deliberate on standards in a gi ven field or area and consists of representatives of 
consumers, traders, academician s, manufacturers, governme nt and other stakeholders. 
Draft Uganda Standards adopted by the Technical Committ ee are widely circulated to stakeholders and the 
general public for comments. The committee reviews the comments before recommending the draft standards 
for approval and declaration as Uganda Standards by the National Standards Council. 
This Draft Uganda Stand ard, DUS EAS 322:2002,  Wood poles and blocks for power and telecommunication 
lines — Specification, is identical with and ha s been reproduced from an East African Standard, EAS 
322:2002, Wood poles and blocks for power and telecommunication lines — Specification,  and is being 
proposed for adoption as a Uganda Standard.  
This standard was developed by the Furniture Standards Technical Committee (UNBS/TC 12).  
Wherever the words, “East African Standard" appea r, they should be replaced by "Uganda Standard." 
 
 EAS 322:2002 
ICS 79.040 
HS 4403.10.0030  
 
 
© EAC 2002                                                                                                     First Edition 20 02  
 
 
 
EAST AFRICAN STANDARD 
 
Wood poles and blocks for power  and telecommunication lines — 
Specification 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
EAST AFRICAN COMMUNITY  
 
 EAS 322:2002  
©EAC 2002 — All rights reserved                                
Foreword  
 
Development of the East African Standards has been necessitated by the need for harmonising 
requirements governing quality of products and services in East Africa. It is envisaged that through 
harmonised standardisation, trade barriers which are encountered when goods and services are exchanged within the Community will be removed.  
 
In order to achieve this objective, the Partner States in the Community through their National Bureaux 
of Standards, have established an East African Standards Committee.  
The Committee is composed of representatives of the National Standards Bodies in Partner States, 
together with the representatives from the private sectors and consumer organisations. Draft East 
African Standards are circulated to stakeholders through the National Standards Bodies in the Partner States. The comments received are discussed and incorporated before finalisation of standards, in 
accordance with the procedures of the Community.  
 
East African Standards are subject to review, to keep pace with technological advances. Users of the 
East African Standards are therefore expected to ensure that they always have the latest versions of the standards they are implementing.  
 
© East African Community 2002 — All rights reserved
* 
East African Community  
P O Box 1096  
Arusha  
Tanzania  Tel: 255 27 2504253/8 Fax: 255-27-2504481/2504255 
E-Mail: eac@eachq.org Web: www.each.org 
 
 
 
 
 
 
 
                                                 
* © 2002 EAC — All rights of exploitation in any form and by any means reserved worldwide for EAC Partner States’ NSBs.  
  
©EAC 2002 — All rights reserved                                                                                           1 
 
 
  
Contents 
 
1 Scope ........................................................................................................................ ..............1 
2 Normative references......................................................................................................... ......1 
3 Definitions.................................................................................................................. ..............1 
4 Felling...................................................................................................................... ................1 
5 Materials requirements ............................ ........................................................................... .....1 
6 Dimensions and permitted tolerances......................................................................................3 
7 Manufacturing requirements ................................................................................................... .4 
8 Stacking and preparation of poles at depots..... .......................................................................5 
9 Moisture content ............................................................................................................. .........5 
10 Poles preservation .......................................................................................................... .........5 
11 Marking and labelling........................... ............................................................................ ........6 
Annex A  Stayblocks and brace blocks........ ................................................................................... ......8 
 
 
 
 EAS 322:2002  
©EAC 2002 — All rights reserved                                
Introduction 
 
One of the important factors involved in the design and economical use of wood poles for the support of aerial communication and power lines is the value of the maximum fibre strength for the different species 
of timber used for wood poles. The fibre strength is affected by the amount of seasoning the wood poles 
have received. The growth characteristics of timber and their freedom from decay and other defects are of importance in the determination of the mechanical 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 properties have of necessity been 
specified in general terms only. It is therefore recommended that the supervision of seasoning tests and 
of preservation processes and the acceptance of poles should be assigned only to qualified and experienced inspectors. 
 
In the preparation of this East African Standard, assistance was drawn from the following: 
 
BS 1990-1:1984,
 Wood poles for overhead power and telecommunication lines published by British 
Standards Institution. 
 
ANSI 05.1:979,  Specifications and dimensions for wood poles published by American National Standards 
Institute. 
 
In reporting the results of a test made in accordance with this East African Standard, if the final value 
observed or calculated is to be rounded off, it shall be done in accordance with EAS 124:1999 
  
 
  
                                
EAST AFRICAN STANDARD                                                EAS 322:2002 
                                                                                                                       
 
©EAC 2002All rights reserved                                                                                                  1  Wood poles and blocks for power and telecommunicat ion lines — 
Specification  
 
1 Scope 
 
This East African Standard specifies materials and performance requirements for solid wood poles. The poles described herein are considered as simple cantilever members subject to transverse loads only. 
 
2 Normative references 
 
For the purposes of this East African Standard, the following references shall apply: 
 EAS 24:2001, 
Glossary of terms used in timber industry 
 
EAS 324:2002, Copper/chromium/arsenic compositions for timber preservations — Methods of timber 
treatment 
 
EAS 323:2002, Specification for wood preservation by means of pressure creosoting 
 
EAS 124:1999, Rounding off numerical values 
 
3 Definitions 
 
For the purpose of this East African Standard, the definitions given in EAS 24 shall apply. 
 
4 Felling  
 
Trees shall be sawn off as close 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 shall be removed as soon as practicable after 
felling except for eucalyptus, which requires a longer seasoning time. 
 
5 Materials requirements 
 
5.1 Species 
 
Poles shall be made from the following species and will have a minimum fibre strengths of 39 Mpa:  
 Trade name  Botanical name   
a) Redwood or scots pine  (Pinus sylvestris)  
b) Corsican pine (Pinus nigra) 
 Douglas fir (Pseudotsuga menziesii) 
 Dunkeld (hybrid)larch (Larix eurolepis)  European larch (Larix decidua) 
 European spruce (Picea abies) 
 Lodgepole pine (Pinus contorta)  Sitka spruce (Picea sitchensi) 
 East African pencil cedar (Juniperus procera) 
 Eucalyptus (Eucalyptus saligna or Eucalyptus grandis) 
 
NOTE The preferred dressed sizes of poles should be as given in Table 1 and Table 2. 
 
5.2 Grading  
 
5.2.1  Prohibited defects  
 
a) Cross-breaks (cracks); 
 EAS 322:2002  
2                                                                                            ©EAC 2002 — All rights reserved                         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;  
 
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. 
 
5.2.2  Permitted defects  
 
a) Firm red heart  — Firm red heart not accompanied by softening or other disintegration (decay) 
of the wood is permitted. 
 
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 permitted. 
 
d) Scars — Turpentine acid face scars are permitted anywhere on the pole surface. 
 
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 shall 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 greatest width of the streak is less than 25 % of the circumference of the pole at the point of measurement. 
 
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 than 10 % of the butt area. Also hollow 
heart does not 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 
scorning or channeling is permitted provided there is no active infestation and the strength of 
the pole is not affected by the degree of damage. 
 
f) Knots — At any cross section along the length of a pole no knot with a diameter measured at 
right angles to the length of the pole, which is greater than 1/5 of the circumference shall be permitted. Also the sum of knot diameters at the cross section shall not exceed 1/4 of the 
circumference of the pole. 
 
NOTE The limitations of knots are based on past practice and satisfactory performance. 
 
g) Scars (cat face) — No pole shall have a scar or turpentine cat face located within 600 mm of 
the groundline. Other sound scars are permitted elsewhere on the pole surface, 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 located between the butt and 600 mm 
below the groundline is not less than the minimum circumference specified at 1.5 m from 
the butt for the class and length of the pole (see Table 1 and Table 2) and 
 
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. 
 EAS 322:2002  
©EAC 2002 — All rights reserved                                                                                           3 
 
 
 h) 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 closer 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 preservative treatment provided that the diameter of the shake is not greater than 50 
% the diameter of the top of the pole. 
 
i) Sweep — Pole shall be free from short crooks. A pole may have sweep in one plane and in one direction, provided that, a straight line joining the surface of the pole at the groundline and 
the edge of the pole at the top in 90 % or more of the inspected lot, shall not be distant from the surface of the pole at any point by more than 25 mm for each 1.5 m of length between 
these points (see Figure 1). In the rest of the inspected lot (i.e. 10 %), the poles may have a 
maximum deviation of 25 mm for each 1.5 m of length measured as above.  
 
 
Figure 1 — Measurement of sweep in one plane and one direction 
 
j) Slope of grain — Spiral grain shall not exceed a slope of 1 in 6. 
 
k) Slits and checks — In the top, a slit or a combination of two single checks; each check 
terminating at the pith centre and separated by not less than 1/6 of the circumference, having 
one or both portions located in a vertical plane with 30 ° of the top bolt hole shall not extend 
downward along the pole more than 150 mm and in the butt, a slit or combination of two single 
checks shall not extend upward along the pole more than 600 mm. All other combination of 
checks or a split shall not extend downward along the pole more than 300 mm. 
 
6 Dimensions and permitted tolerances  
 
6.1 Size of poles 
 
This East African Standard shall be applicable to preferred dressed sizes of poles as given in Table 1 
and Table 2. 
 
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 than 75 mm shorter or 150 mm longer than the nominal length (see 7.2). 
 
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. 
 
EAS 322:2002  
4                                                                                            ©EAC 2002 — All rights reserved                         Table 1 — Preferred dimensions of poles for power distributions 
 
 
Pole class  
Pole length 
 
 
m  
Min. pole top 
diameter 
 
mm  
Max. pole top 
dia 
 
mm  
Min. dia 1.5 m 
from butt 
 
mm  
Groundline 
Distance from 
the butt 
m     * 
 
Light 9 
10 
11 12 13 150 
150 
170 180 200 175 
180 
190 200 220 200 
210 
220 240 250 1.5 
1.8 
1.8 2.0 2.2 
 
Medium 9 
10 
11 
12 
13 14 170 
180 
190 
195 
200 210 190 
200 
210 
220 
230 240 230 
240 
250 
260 
270 280 1.5 
1.8 
1.8 
2.0 
2.2 2.2 
 Stout 9 
10 
11 
12 
13 
14 190 
190 
195 
200 
210 
220 240 
245 
250 
250 
255 
260 285 
295 
305 
320 
330 
340 1.5 
1.8 
1.8 
2.0 
2.2 
2.2 
* The figures in this column are intended for use only when a definition of groundline is necessary in order to apply 
requirements relating to scars, straightness, etc.  
 
Table 2 — Preferred dimensions of poles for aerial telecommunications 
 
Pole class Pole length 
   
m Pole top diameter    
Min.         Max. 
  
mm Min. dia 1.5m from 
butt 
  
mm Groundline   
distance from the 
butt      * 
 
m 
 Light 6 
7 
7.5 90 
90 
90 120 
120 
120 120 
130 
135 1.2 
1.2 
1.3 
 Medium 7 
7.5 
8 120 
120 120 140 
140 140 150 
155 160 1.2 
1.3 1.5 
 
Stout 9 
10 
11 130 
130 
130 150 
150 
150 175 
185 
195 1.5 
1.5 
1.9 
* The figures in this column are intended for use only when a definition of groundline is necessary in order to apply 
requirements relating to scars, straightness, etc.  
 
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 sapwood. 
 
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 cut with an inverted "V" section, each side of the "V" having a 
30° slope to the pole axis or flat top cut; 90°± 5° perpendicular to the central axis and shall be bound with 
anti-cracking plate. EAS 322:2002  
©EAC 2002 — All rights reserved                                                                                           5 
 
 
  
7.4 Trimming  
 
Knots on the pole surface, whether partially or fully grown and branch stubs shall be trimmed close. 
Trimming may be done by shaving machine or by hand.  
7.5 Shaving 
 If shaving is used, the depth of cut 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 lower 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.  Drilled holes shall be positioned at right angles to any pole top spilt.  All drilling and 
fabrication shall be carried out before preservative treatment. 
 
8 Stacking and preparation of poles at depots 
 
All poles other than spruce 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 strain 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. 
 
9 Moisture content 
 
Preservation of species other than spruce shall not take place until the average moisture content of 
each batch of the poles is reduced to not more than 28 %.  No individual pole in the batch shall have a moisture content greater than 30 %. 
 
The moisture content of the poles shall be determined prior to treatment by the oven test method or any other suitable method in accordance with the method described in annex B of EAS 323. 
 
Poles for preservation shall be protected against heavy and continuous rain. 
 
10 Poles preservation 
 
The following species shall be pressure impregnated 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 
 
When pressure impregnating in accordance with EAS 323, the coal tar creosote used shall comply 
with type 2 and the average net retention of preservative in a charge shall be not less than 115 kg/m
3. 
 EAS 322:2002  
6                                                                                            ©EAC 2002 — All rights reserved                         When pressure impregnating in accordance with EAS 324, the copper/chromium/arsenic mixture shall 
have a solution strength not less than 3 % (m/v) and the average net retention of preservatives in a 
charge shall be not less than 14 kg/m3 
 
Since sitka spruce cannot be treated with preservative in the normal way by the procedures described in EAS 323 and EAS 324, it shall be treated using a suitable modification of one of the procedures 
described in those standards to meet the requirements for full sapwood penetration and net retention. 
 
11 Marking and labelling 
 
11.1 General 
 
Each pole shall have a gouge or brand mark at least 50 mm long, 5 mm wide and 3 mm deep placed 
3 m from the butt and shall be marked with certain information in characters not less than 25 mm high and gouged or branded 5 mm wide and 3 mm deep. Spacing between codes shall be between 20 mm 
and 30 mm. The coded information shall include the following: 
 a) the name or mark of the preserver and/or the depot supplying the pole; 
 
b) pole length in metres;  
c) pole class (
L for light,  M for medium and S for stout ); 
 
d) Species code, i.e.  
CP Corsican pine, 
 
SP Scots pine or Redwood, 
 EA
 East African pencil cedar, 
 
SS Sitka spruce, 
 LP
 Lodgepole pine, 
 
LD Larch Dunkeld, 
 
E Eucalyptus and 
 
e) last two digits of year of preservation.  
The layout of these markings is shown in Figure 2. 
 Pole treated with creosote shall carry no other distinguishing mark. Appropriate letters shall denote 
other forms of preservation. 
 
11.2  In the butt end 
 Each pole shall also have the pole length in metres and the 
pole class  impressed on the pole butt. EAS 322:2002  
©EAC 2002 — All rights reserved                                                                                           7 
 
 
  
Figure 2 — Markings layout  
 
EAS 322:2002  
8                                                                                            ©EAC 2002 — All rights reserved                          
Annex A 
 
Stayblocks and brace blocks 
 
 
A.1 Materials requirements 
 
Preferably stayblock and brace blocks shall be sourced from 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 blocks may be cut from sa wn timber or from 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 wi th 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 possible 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 size 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 face. 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 calculations are based on installation of sand of density of 550 
kg/m3, which is considered to be representative of average worst ground 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.  EAS 322:2002  
©EAC 2002 — All rights reserved                                                                                           9 
 
 
  
 
 
 
 
 
 
 
 
 
 
 
 
Figure 3 —Stayblocks dimensions 
 
 
 
 
 
 
EAS 322:2002  
10                                                                                            ©EAC 2002 — All rights reserved                          
 
 
 
  
 
 
 
Figure 4 — Brace blocks dimensions  
 
 
  
 
  
EAS 322:2002 
 
 
 
©EAC 2002 — All rights reserved