Steel lattice towers for 10, 20 and 35 kV transmission · PDF fileSTEEL LATTICE TOWERS FOR 10,...

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Steel lattice towers for 10, 20 and 35 kV transmission lines INSTRUCTIONS FOR DEPLOYMENT OF TOWERS PROJEKT

Transcript of Steel lattice towers for 10, 20 and 35 kV transmission · PDF fileSTEEL LATTICE TOWERS FOR 10,...

Page 1: Steel lattice towers for 10, 20 and 35 kV transmission · PDF fileSTEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES 5 3. 1. TOWER HEAD TYPES On towers it is possible to

Publisher: DALEKOVOD-PROJEKT d.o.o., 2010.e-mail: [email protected]

Steel lattice towers for 10, 20 and 35 kV transmission lines

INSTRUCTIONS FOR DEPLOYMENT OF TOWERS

www.dalekovod.com

PROJEKT

Ovitak engleski.indd 1Ovitak engleski.indd 1 3/26/10 2:20 PM3/26/10 2:20 PM

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

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1. INTRODUCTION 3

2. BASIC INFORMATION ON PURPOSE AND STRUCTURE OF TOWERS 3

3. CONDUCTOR ARRANGEMENT ON THE TOWER 5

3.1. TOWER HEAD TYPES 5

3.2. OPTIONS FOR MODELLING TOWER HEADS 7

4. TOWER TYPES AND STRENGTH CAPACITY 8

4.1. TOWER TYPES 8

4.2. TABLE WITH DRAFTS AND DATA ON ADMISSIBLE TOWER LOADS 9

NAH2 10

NAL2 11

NAP2 12

ZAE2 13

ZAH2 14

ZAJ2 15

ZAL2 16

ZAM2 17

4.3. EXAMPLE OF SELECTING AND MONITORING TOWERS

FOR CERTAIN LOAD CONDITIONS 18

5. RECOMMENDED SELECTION OF TOWERS (APPLICATION TABLES) 21

5.1. MOST COMMON STRUCTURE AND CROSS SECTIONS

FOR NON INSULATED CONDUCTORS IN DIFFERENT CLIMATE CONDITIONS 21

5.2. CONDUCTOR SUSPENSION SETS 23

5.3. CONDUCTOR TENSION SETS 32

6. ORDERING INFORMATION AND STRUCTURE TAKEOVER 34

7. ASSEMBLING THE STRUCTURE 36

8. TOWER FOUNDATION 38

TABLE OF CONTENTS

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In order to comprise all requirements of distributors, and at the same time use the simplest possible storage solutions

and to reduce maintenance costs i.e. to unify the construction, a suitable group of steel lattice towers was designed for

assembling 20 (10 and 35) kV distribution lines. Towers were designed between 1980 and 1983 for the requirements of

the Elektroprivreda company, as part of the medium voltage tower standardisation program for ZEOH at that time, and

are now part of the DALEKOVOD d.d. Zagreb manufacturing assortment.

By using extensive experience in design, production and construction of transmission line towers and data on their use,

3 suspension (N – NAH, NAL and NAP) and 5 tension (Z – ZAE, ZAH, ZAJ, ZAL and ZAM) towers were designed, in line

with the “Regulation on Technical Standards for Construction of Overhead Power Lines of Nominal Voltage Between 1

and 400 kV” Offi cial Gazette 65/88 (O.G.RH 55/96), where each of them can be used in diff erent conditions present on

the transmission line route.

For each tower type a structure prototype was made and it was tested under test load. Based on the examination of the

project documentation (calculations and manufacturing blueprints), examination of the prototype structure, testing

results and by participation in tests, IGH as the authorised organisation issued attests on testing.

Over 25 years of experience in using towers indicated all structural advantages, precisely because of the possibility

of their diff erentiated use, their suitability to most common situations and deployment requirements. Accordingly,

new types of accessorises and new manufacturing technology improvements were made to: the structure itself,

presentation of acceptable loads and methods for control and selection of the structure model for the relevant load of

each single tower design type group. To the names of towers the additional mark 2 was added, (N – NAH2, NAL2 and

NAP2) and (Z – ZAE2, ZAH2, ZAJ2, ZAL2 and ZAM2).

For each single tower type a project documentation was prepared according to the currently valid technical regulations

and professional HEP standards (Steel Lattice Tower Standardisation for 20(10) kV Network, mark N.022.03, class no.

4.08/92).

These instructions are intended for designers, builders and contractors of medium voltage transmission

lines, as also to employees in charge of their maintenance, and are to insure quick and simple reference in

selecting and deploying structures, i.e. in reaching the optimum solution.

1. INTRODUCTION

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2. 1. THE PURPOSE OF THE STRUCTURE

With diff erence from towers designed for very specifi c cross sections and structures of conductors, these towers

represent typifi ed structure solutions where each type can be used in diff erent geographical conditions for more

diff erent types of conductors, with diff erent cross sections and structures.

For the required conductor cross-section and specifi c locations, by correct selection of the maximum working stress

and corresponding arrangement of suspensions, i.e. points of connecting the earth wire to the structure, each tower

can be used:

in all climate conditions:

• nominal wind load 500 – 1100 (1300) N/m2

• additional load coeffi cient 1 to 4 x 0.18.d daN/m’

on all terrains, without regard of the confi guration

for earth wires with diff erent cross-sections:

• AL/Č between 35/6 mm2 and 150/25 mm2

• other types of insulated and non insulated conductors, that put weight on the tower

with the corresponding resulting tension force and wind facing surface

for connecting post type, long rod, string insulators (directly to the cross-arm, over hinges, shackles, extension

links and spacers)

for one, and for two systems

with, or without earth wire

for use of additional equipment without requiring customisation of the structure:

• overhead and underground cable tap-off s, overhead-underground transition

• line disconnectors (with or without remote control), malfunction detection, etc.

as gantries

2. BASIC INFORMATION ON PURPOSE AND STRUCTURE OF TOWERS

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2. 2. BASIC STRUCTURE INFORMATION

Towers are four sided pyramids of steel - lattice grid. Made of standard hot rolled profi les connected with bolts, with

single diagonal fi lling in the total length of the tower. Two sides of suspension towers that are designed for light and

medium loads shall be made of horizontal steel plate welded to tower main legs instead of diagonals fi xed with bolts.

Corrosion protection of all tower parts is made by hot dip galvanizing, in quality that satisfi es renown world standards.

All towers are designed with parallel sides of the upper section (tower head without incremental adjustments). In this

way it is possible to use same cross-arms for diff erent disposition of earth wires – numerous diff erent symmetrical and

asymmetrical heads, and makes possible to connect same accessories on diff erent tower heights as also on diff erent

types of towers.

Tower sections with incremental adjustment are selected on purpose to use one or at most two diff erent profi le

dimensions for tower main legs at all heights. Each tower section diagonal has the same length, profi le dimension and

corresponding bolts.

Type, material, dimensions and manufacturing of tower structures enable:

simple storage and transport (for diff erent dimensions and transportation means)

quick installation and removal (by elements, sections, as a whole) with or without mechanisation

changing the function of a tower on the already constructed transmission lines

simple maintenance and interventions during exploitation:

• open profi les suitable for monitoring and maintenance

• simple replacement of damaged elements and reparation of corrosion protection

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3. 1. TOWER HEAD TYPES

On towers it is possible to have virtually any arrangement of conductors i.e. any tower head type.

Types used for non insulated conductors are:

Symmetrical heads formed by two sided cross-arms

• G – gama

• D – delta

• T – trapez [trapezium]

• B, BU – bačva [barrel] (B without, and BU with the earth wire)

Asymmetrical heads formed by one sided cross-arms

• J, JU – jela [fi r] (J without, and JU with the earth wire)

Cross-arms are mounted on the upper section of the tower with the possibility of connection on every 0.85 m of the

section, where necessary. For the central conductor of the head D and for the earth wire on heads BU and JU, the top

frame structure is mounted at the top of the tower, hereinafter named only as – top.

Besides cross-arms for types of tower heads, it is also possible to attach on towers suspension equipment and structures

(frames, cross-arms, etc.) customised for suspending insulated conductors, cables, devices, etc.

3. CONDUCTOR ARRANGEMENT ON THE TOWER

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TOWER HEAD TYPES

SYMMETRICAL HEADS

G - GAMA

D - DELTA

B, BU - BAČVA [BARREL] T - TRAPEZ [TRAPEZIUM]

ASYMMETRICAL HEADS

J, JU - JELA [FIR]

HEAD CONSTRUCTION

CROSS-ARM LENGTH a, b, c = 0.95 1.20. 1.45. 1.60 (1.80)m SPACING BETWEEN CROSS-ARMS x, y, z = nx0.85m HEAD HEIGHT s=x+y+z USEFUL TOWER HEIGHT h=H-S DESIGNATION OF THE HEAD SHAPEG, D, B, T, J = towers without earth wire x = 0BU, JU = towers with earth wire x = n x 0.85

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3. 2. OPTIONS FOR MODELLING TOWER HEADS

SYMMETRICAL HEAD CROSS-ARMS

ASYMMETRICAL HEAD CROSS-ARMS

TOP

DOUBLE SIDED CONSOL ONE SIDED CONSOL

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4. 1. TOWER TYPES

Basic purpose:

suspension – line towers in the transmission line route: NAH2, NAL2, NAP2

tension: ZAE2, ZAH2, ZAJ2, ZAL2, ZAM2

The order of towers corresponds to the tower weight order and their implementation from lighter conditions towards

the heavier load on the transmission line route.

Tension towers for transmission lines, besides their main purpose to decrease the load, angle-tension, end-tower and

towers with tap-off s, can also be used as suspension ones (in case larger medium spans and/or higher towers are

required).

Nominal height: 9 m, 11 m, 13 m, 15 m – all towers (tower NAH2 up to 13 m for standard use)

17 m, 19 m and 21 m – additional height for tension towers

Nominal heights are specifi c for all tower types, and they should be used when placing orders. The actual height from

bottom to top, according to the manufacturing documentation is equal to nominal height with tolerance between -

0.5 m and + 0.25 m, depending on the tower type and height. It is indicated on the sketch of each tower, above the

nominal height indicated in brackets. Tower height from the connection point on the tower top to the ground is equal

to the real height of the structure, according to the sketch of the tower + height of the foundation. Overall standard

increase of height from the foundations amounts to 30 cm and can be increased for certain tower locations if necessary.

To reduce the costs of solving property issues when constructing transmission lines, additional tower heights were

designed. They make possible to use towers with longer spans and to reduce the number of towers in the transmission

line route.

TOWER STRENGTH CAPACITY - NOMINAL TOWER LOAD

The strength capacity of each single tower is conditioned by the basic implementation i.e. load conditions for which

the tower is designed for, and are defi ned by the nominal load and allowed torque with the resulting sum of horizontal

forces. Nominal load corresponds to the maximum force on the top of the tower, that tower main legs can support for

certain load according to the mentioned Regulation for Overhead Power-lines. Values stated for loads caused by wind

relate to payload.

The strength capacity of each tower is controlled by testing the structure prototype used for its basic purpose, and this

is certifi ed by the adequate attest.

4. TOWER TYPES AND STRENGTH CAPACITY

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4. 2. TOWER TABLES

According to the table of allowed tower loads it is possible to select, i.e. to monitor the tower for diff erent types of the

head and for diff erent load combinations (standard use, additional tap-off s, during reconstruction, repairs, etc.).

Tables also state the recommended dimensions of the foundation for specifi c tower heights in relation to the

characteristic soil bearing capacity, and approximate weight of the tower structure without cross-arms.

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SUSPENSION TOWER NAH2

Nominaltowerheight

Towerweight

Foundationpart

L

Soilσ

dop

FoundationdimensionsA T

m kg cm kN/m2 cm

9 290 139

120 + PV 80 190150 60 180

200 + PV 80 170250 60 160

≥500 60 150

11 360 141

120 + PV 80 200150 60 190

200 + PV 80 180250 60 170

≥500 60 150

13 420 146

120 + PV 80 200150 60 190

200 + PV 80 180250 60 170

≥500 60 150

Tower type mark NAH2 Nominal voltage 20 (35) kV Nominal tower height(s) 9, 11, 13 m Nominal load Rx, Ry (allowed horizontal load Hx and Hy reduced to the tower top - over the tower height)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

Cross-armlengtha, b, c

Admissible load on the cross-arm top:Hy

art. 69.1Vz

art. 68.1a, 69.1.m kN

0.95 3.25 7.001.20 2.70 5.001.45 2.30 3.401.60 1.90 2.80

art. 69.1exceptional

load

2.

Basic wind load - W

Nominal tower height

Nominal load for ∑ Vz = 8kN

Rx (Ry=0)art. load 68.1b

Ry (Rx=0)art. load 68.1c

N/m2 m kN

500

9 5.5 3.311 4.8 2.513 4.6 2.1

(15) 3.7 1.4

600

9 5.4 3.111 4.6 2.213 4.4 1.7

(15) 3.5 1.0

750

9 5.2 2.711 4.3 1.913 4.1 1.3

(15) 2.4 0.6

9009 5.0 2.5

11 4.0 1.513 3.7 0.9

11009 4.7 2.0

11 3.6 0.913 1.8 0.4

1.

SIDE X SIDE Y

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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Nominaltowerheight

Towerweight

Foundationpart

L

Soilσ

dop

FoundationdimensionsA T

m kg cm kN/m2 cm

9 320 138

120 + PV 80 210150 80 180

200 + PV 80 190250 80 160

≥500 80 150

11 425 144

120 + PV 80 220150 80 190

200 + PV 80 200250 80 170

≥500 80 150

13 490 111

120 + PV 100 220150 100 190

200 + PV 100 200250 100 170

≥500 100 150

15 620 144

120 + PV 100 230150 100 200

200 + PV 100 210250 100 180

≥500 100 150

Tower type mark NAL2

Nominal voltage 20 (35) kVNominal tower height(s) 9, 11, 13, 15 mNominal load Rx, Ry(allowed horizontal load Hx and Hy reduced to the tower top - over the tower height or 10.3 m)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

Cross-armlengtha, b, c

Admissible load on the tower peak:Hy

art. 69.1Vz

art. 68.1a, 69.1.m kN

0.95 5.2 11.01.20 4.4 8.91.45 3.8 6.31.60 2.7 5.2

art. 69.1exceptional

load

2.

Basic wind load - W

Nominal tower height

Nominal load for ∑ Vz = 10.6kN

Rx (Ry=0)art. load 68.1b

Ry (Rx=0)art. load 68.1c

N/m2 m kN

500

9 6.8 3.711

6.5 2.91315

600

9 6.7 3.411

6.3 2.61315

750

9 6.4 3.011

5.9 2.21315

900

9 6.1 2.611

5.5 1.61315

1100

9 5.7 2.011

5.0 1.31315

1.

SUSPENSION TOWER NAL2

SIDE X SIDE Y

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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Basic wind load - W

Nominal tower height

Nominal load for ∑ Vz = 8kN

Rx (Ry=0)art. load 68.1b

Ry (Rx=0)art. load 68.1c

N/m2 m kN

500

9

10.7

8.211 7.013 6.915 5.5

600

9

10.5

7.911 6.813 6.515 5.1

750

9

10.3

7.511 6.213 5.815 4.3

900

9

10.1

7.011 5.513 5.015 3.4

1100

9

9.8

6.111 4.713 4.115 2.5

Nominaltowerheight

Towerweight

Foundationpart

L

Soilσ

dop

FoundationdimensionsA T

m kg cm kN/m2 cm

9 390 124

120 + PV 100 220150 100 190

200 + PV 100 200250 100 170

≥500 100 160

11 575 177

120 + PV 120 220150 120 190

200 + PV 120 200250 120 170

≥500 120 160

13 650 101

120 + PV 120 230150 120 200

200 + PV 120 210250 120 170

≥500 120 160

15 785 185

120 + PV 120 240150 120 200

200 + PV 120 220250 120 180

≥500 120 160

Tower type mark NAP2

Nominal voltage 20 (35) kVNominal tower height(s) 9, 11, 13, 15 mNominal load Rx, Ry(allowed horizontal load Hx and Hy reduced to the tower top - over the 8.5 m section)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

Cross-armlengtha, b, c

Admissible load on the cross-arm top:Hy

art. 69.1Vz

art. 68.1a, 69.1.m kN

0.95 8.3 11.01.20 7.8 8.01.45 6.9 6.01.60 6.4 5.2

art. 69.1exceptional

load

2.

1.

SUSPENSION TOWER NAP2

SIDE X SIDE Y

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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Load situation

Allowed load1. Reduced to the tower top 2. At the point of action on the structure

R=Rx+Ry Vertical load ∑Vz

Horizontal load for torque (kNm) Basic wind

load - WMt=0 Mt=5.2

∑Hx ∑Hy ∑Hx ∑HyArt. kN kN kN kN N/m2

68.1

a 11.3 20 19.5 19.5 11.5 11.5 -

b10.2

815.0 19.5 8.0 11.5

Wx1100

11.0 17.5 19.5 9.0 11.5 600

c9.0

819.5 14.0 11.5 7.5

Wy1100

10.3 19.5 17.0 11.5 8.5 60068.2 11.9 8 19.5 19.5 11.5 11.5 -

69.2Exceptional

Mt=8.6 Mt=10.715.5 20.0 9.0 9.0 7.6 7.6 -

Cross-arm lengtha, b, c

3. Allowed vertical load Vz on the cross-arm for:

Hy=0 kN Hy=5.3 kN Hy=7.7 kN Hy=10.42 kN

m kN kN kN kN0.95 11.8 11.3 11.0 10.71.20 8.9 8.3 8.0 7.71.45 6.3 6.1 6.0 5.71.60 5.2 5.2 5.2 4.7

Nominal tower height

Tower weight

Foundation part

L

Soilσ

dop

Foundation dimensions

A Tm kg cm kN/m2 cm

9 390 112

120 + PV 140 200150 120 180

200 + PV 140 180250 120 160

≥500 120 160

11 500 168

120 + PV 140 220150 140 180

200 + PV 140 200250 140 160

≥500 140 160

13 585 106

120 + PV 160 220150 140 190

200 + PV 140 210250 140 170

≥500 140 160

15 715 183

120 + PV 160 230150 160 190

200 + PV 160 200250 160 170

≥500 160 160

Tower type mark ZAE2

Nominal voltage 20 (35) kVNominal tower height(s) 9, 11, 13, 15 m (17, 19, 21 m)Nominal load R=Rx + Ry(allowed horizontal load Hx and Hy reduced to the tower top - over the 8.8 m section)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

The tower can be used only if all three conditions for allowed load (1, 2 and 3) are satisfi ed

TENSION TOWER ZAE2

SIDE X

TOWER PEAK PLAN VIEW

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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Load situation

Allowed load1. Reduced to the tower top 2. At the point of action on the structure

R=Rx+Ry Vertical load ∑Vz

Horizontal load for torque (kNm) Basic wind

load - WMt=0 Mt=7.5

∑Hx ∑Hy ∑Hx ∑HyArt. kN kN kN kN N/m2

68.1

a 17.6 34.0 28.0 28.0 16.0 16.0 -

b17.0

10.026.0 28.0 14.0 16.0

Wx1100

17.8 27.0 28.0 15.0 16.0 600

c16.2

10.028.0 25.0 16.0 13.0

Wy1100

17.3 28.0 26.0 16.0 14.0 60068.2 18.9 10.0 28.0 28.0 16.0 16.0 -

69.2exceptional

Mt=12.5 Mt=15.024.2 34.0 19.0 19.0 14.0 14.0 -

Cross-arm lengtha, b, c

3. Allowed vertical load Vz on the cross-arm for:

Hy=0 kN Hy=5.3 kN Hy=7.7 kN Hy=10.42 kN

m kN kN kN kN0.95 11.8 11.2 11.0 10.71.20 8.9 8.3 8.0 7.71.45 6.3 6.1 6.0 5.71.60 5.2 5.2 5.2 4.7

Nominal tower height

Tower weight

Foundation part

L

Soilσ

dop

Foundation dimensions

A Tm kg cm kN/m2 cm

9 570 112

120 + PV 140 230150 120 200

200 + PV 140 210250 120 180

≥500 120 180

11 730 168

120 + PV 140 240150 140 200

200 + PV 140 220250 140 180

≥500 140 160

13 860 106

120 + PV 160 240150 160 200

200 + PV 160 220250 160 180

≥500 140 160

15 1045 183

120 + PV 160 250150 160 210

200 + PV 160 230250 160 190

≥500 160 160

Tower type mark ZAH2

Nominal voltage 20 (35) kVNominal tower height(s) 9, 11, 13, 15 m (17, 19, 21 m)Nominal load R=Rx + Ry(allowed horizontal load Hx and Hy reduced to the tower top - over the 8.8 m section)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

The tower can be used only if all three conditions for allowed load (1, 2 and 3) are satisfi ed

TENSION TOWER ZAH2

SIDE X

TOWER PEAK PLAN VIEW

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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Load situation

Allowed load1. Reduced to the tower top 2. At the point of action on the structure

R=Rx+Ry Vertical load ∑Vz

Horizontal load for torque (kNm) Basic wind

load - WMt=0 Mt=7.5

∑Hx ∑Hy ∑Hx ∑HyArt. kN kN kN kN N/m2

68.1

a 26.0 36.0 39.0 39.0 23.5 23.5 -

b23.5

12.036.0 39.0 19.0 23.5

Wx1100

25.2 37.0 39.0 20.0 23.5 600

c22.8

12.039.0 35.0 23.5 18.0

Wy1100

24.3 39.0 36.0 23.5 19.0 60068.2 27.3 12.0 39.0 39.0 23.5 23.5 -

69.2Exceptional

Mt=17 Mt=21.535.8 36.0 26.0 26.0 18.0 18.0 -

Cross-arm lengtha, b, c

3. Allowed vertical load Vz on the cross-arm for:

Hy=0 kN Hy=5.3 kN Hy=7.7 kN Hy=10.42 kN

m kN kN kN kN0.95 11.8 11.2 11.0 10.71.20 8.9 8.3 8.0 7.71.45 6.3 6.1 6.0 5.71.60 5.2 5.2 5.2 4.7

Nominal tower height

Tower weight

Foundation part

L

Soilσ

dop

Foundation dimensions

A Tm kg cm kN/m2 cm

9 730 114

120 + PV 160 240150 120 220

200 + PV 160 210250 120 200

≥500 120 170

11 935 170

120 + PV 160 250150 140 220

200 + PV 160 230250 140 200

≥500 140 170

13 1140 106

120 + PV 160 260150 160 220

200 + PV 160 240250 160 200

≥500 160 170

15 1390 183

120 + PV 160 280150 160 230

200 + PV 160 250250 160 210

≥500 160 170

Tower type mark ZAJ2

Nominal voltage 20 (35) kVNominal tower height(s) 9, 11, 13, 15 m (17, 19, 21 m)Nominal load R=Rx + Ry(allowed horizontal load Hx and Hy reduced to the tower top - over the 8.8 m section)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

The tower can be used only if all three conditions for allowed load (1, 2 and 3) are satisfi ed

TENSION TOWER ZAJ2

SIDE X

TOWER PEAK PLAN VIEW

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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TENSION TOWER ZAL2

Load situation

Allowed load1. Reduced to the tower top 2. At the point of action on the structure

R=Rx+Ry Vertical load ∑Vz

Horizontal load for torque (kNm) Basic wind

load - WMt=0 Mt=7.5

∑Hx ∑Hy ∑Hx ∑HyArt. kN kN kN kN N/m2

68.1

a 34.5 46.0 55.0 55.0 35.0 35.0 -

b33.6

14.850.0 55.0 30.0 35.0

Wx1100

34.9 52.0 55.0 31.0 35.0 600

c33.0

14.855.0 49.0 35.0 29.0

Wy1100

34.5 55.0 51.0 35.0 30.0 60068.2 36.2 14.8 55.0 55.0 35.0 35.0 -

69.2Exceptional

Mt=22 Mt=2947.5 46.0 41.0 41.0 26.0 26.0 -

Cross-arm lengtha, b, c

3. Allowed vertical load Vz on the cross-arm for:

Hy=0 kN Hy=5.3 kN Hy=7.7 kN Hy=10.42 kN

m kN kN kN kN0.95 11.8 11.2 11.0 10.71.20 8.9 8.3 8.0 7.71.45 6.3 6.1 6.0 5.71.60 5.2 5.2 5.2 4.7

Nominal tower height

Tower weight

Foundation part

L

Soilσ

dop

Foundation Dimensions

A Tm kg cm kN/m2 cm

9 1035 130

120 + PV 180 240150 140 230

200 + PV 180 220250 140 200

≥500 120 180

11 1305 183

120 + PV 180 260150 140 240

200 + PV 180 230250 140 210

≥500 140 180

13 1485 189

120 + PV 180 270150 160 240

200 + PV 180 240250 160 210

≥500 160 180

15 1825 183

120 + PV 180 280150 160 250

200 + PV 180 260250 160 220

≥500 160 190

Tower type mark ZAL2

Nominal voltage 20 (35) kVNominal tower height(s) 9, 11, 13, 15 m (17, 19, 21 m)Nominal load R=Rx + Ry(allowed horizontal load Hx and Hy reduced to the tower top - over the 10.45 m section)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

The tower can be used only if all three conditions for allowed load (1, 2 and 3) are satisfi ed

SIDE X

TOWER PEAK PLAN VIEW

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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Load situation

Allowed load1. Reduced to the tower top 2. At the point of action on the structure

R=Rx+Ry Vertical load ∑Vz

Horizontal load for torque (kNm) Basic wind

load - WMt=0 Mt=7.5

∑Hx ∑Hy ∑Hx ∑HyArt. kN kN kN kN N/m2

68.1

a 45.0 58.0 68.0 68.0 40.5 40.5 -

b41.8

16.065.0 68.0 35.0 40.5

Wx1100

44.8 66.0 68.0 36.0 40.5 600

c41.1

16.068.0 64.0 40.5 34.5

Wy1100

44.4 68.0 65.0 40.5 35.5 60068.2 47.2 16.0 68.0 68.0 40.5 40.5 -

69.2Exceptional

Mt=27 Mt=3862.0 58.0 50.0 50.0 31.0 31.0 -

Cross-arm lengtha, b, c

3. Allowed vertical load Vz on the cross-arm for:

Hy=0 kN Hy=5.3 kN Hy=7.7 kN Hy=10.42 kN

m kN kN kN kN0.95 11.8 11.2 11.0 10.71.20 8.9 8.3 8.0 7.71.45 6.3 6.1 6.0 5.71.60 5.2 5.2 5.2 4.7

Nominal tower height

Tower weight

Foundation part

L

Soilσ

dop

Foundation dimensions

A Tm kg cm kN/m2 cm

9 1260 130

120 + PV 200 250150 160 230

200 + PV 200 220250 140 210

≥500 120 180

11 1600 183

120 + PV 200 260150 160 240

200 + PV 200 240250 140 230

≥500 140 200

13 1850 189

120 + PV 200 280150 160 260

200 + PV 200 250250 160 230

≥500 160 190

15 2260 183

120 + PV 200 290150 160 270

200 + PV 200 260250 160 240

≥500 160 200

Tower type mark ZAM2

Nominal voltage 20 (35) kVNominal tower height(s) 9, 11, 13, 15 m (17, 19, 21 m)Nominal load R=Rx + Ry(allowed horizontal load Hx and Hy reduced to the tower top - over the 12.5 m section)Basic load safety factor 1.5Exceptional load safety factor 1.1Wind force on the structure 2.6xW

The tower can be used only if all three conditions for allowed load (1, 2 and 3) are satisfi ed

TENSION TOWER ZAM2

SIDE X

TOWER PEAK PLAN VIEW

TOWER FOUNDATION

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

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4. 3. EXAMPLE OF SELECTING AND MONITORING TOWERS FOR CERTAIN LOAD CONDITIONS

The resulting force reduced to the top of the tower for a specifi c load must be less or equal to the nominal load. Also, it

is necessary to fulfi l the combined conditions including the allowed torque, sum of horizontal forces and the allowed

load on the cross-arms, depending on the length of the cross-arm. In case of higher then permitted vertical load on the

cross-arm, the cross-arm should be reinforced by stays or props.

Rx, Ry, – load reduced to the tower top

Hx, Hy, Vz, – load at the point of action on the structure

Rx = (Hx1· h

1+Hx

2· h

2+Hx

3· h

3+⏐Vz

2–Vz

3⏐· .a) /h

R

Ry = (Hy1· h

1+Hy

2· .h

2+Hy

3· h

3) / h

R

Rx + Ry ≤ dopR

MT = ⏐Hy

2 - Hy

3⏐· a

ΣHx = Hx1 + Hx

2 + Hx

3 ≤ dopΣHx

ΣHy = Hy1 + Hy

2 + Hy

3 ≤ dopΣHy

ΣVz = Vz1 + Vz

2 + Vz

3 ≤ dopΣVz

h R =

sec

tion

of lo

ad r

educ

tion

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Load in line with the “Regulation on Overhead Power Lines of Nominal Voltage Between 1 and 400 kV” (Offi cial Gazette

no. 65/88, OG no. 55/96).

Load situation art.

Vx Vy Vz Zx Zy Zz Sx Sy

kN kN kN kN kN kN kN/m2 kN/m2

68.1

a 5.4 - 6.8 4.3 - 4.2 - -

b 6.1 - 2.5 4.3 - 1.12.6 x0.9

-

c 3.6 0.7 2.5 2.9 0.4 1.1 -2.6 x0.9

68.2 1.8 6.7 2.5 1.4 5.3 1.1 - -

69.2

P.V. 2.7 10.1 6.8 - - -

- -

N.V. 5.4 - 6.8 4.3 - 4.2

Pzu - - - 2.1 8.0 4.2

- -

Nzu 5.4 - 6.8 - - -

EXAMPLE

conductors: 3 x Al/č 95/15 mm2, σ = 95 N/mm2

earth wire: ČIII 35 mm2 , σ = 240 N/mm2

semi-sum of adjacent spans: aW

= 200 m

weight span: agr

= 400 m

wind pressure (load): w = 900 N/m2

additional load: dt = 1.6 x 0.18 √d daN/m’

purpose of the tower on the route: angle-tension

line route deviation angle: α = 150°

selected head type: JU22 Hyp

othe

tical

tow

er Z

AJ

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Reduced to the top of the tower and sum of forces:

Load situation art. 68.1.b.

Rx =[4.3x8.8+6.1x(7.1+5.4+4.55)+2.5x1.45]/8.8 = 16.6 kN

Ry = 0

R = 16.6 kN

∑Vz =1.1+3x2.5 = 8.6 kN

∑Hy = 0

∑Hx = 4.3+3x6.1 = 22.6 kN

MT = 0

Load situation art. 68.2.

Rx = (1.4x8.8+1.8x17.05+2.5x1.45)/8.8 = 5.30 kN

Ry = (5.3x8.8+6.7x17.05)/8.8= 18.30 kN

R = 23.6 kN

∑Vz = 8.6 kN

Selected:

tower ZAJ2 dop R = 27.3 kN > 23.6 kN

dop ∑Vz = 12 kN > 8.6 kN

MT = 6.7 x 1.45 = 9.7 kNm < 10.5 kNm

∑Hy = 5.3+3x6.7 = 25.4 kN < dop ∑Hy = 28.5 kN za MT = 10.5 kNm

∑Hx = 1.4+3x1.8 = 6.8 kN < dop ∑Hx = 28.5 kN za MT = 10.5 kNm

control for load situation art. 68.1.b.

∑Hx = 22.6 kN < dop ∑Hx = 36 kN za MT = 0

Load situation art. 69.2.

MT = 10.1x1.45 = 14.7 kNm < 17 kNm

∑Hx = 4.3+2.7+2x5.4 = 17.8 kN < 26 kN za MT = 17 kNm

∑Hy = 10.1 kN < 26 kN za MT = 17 kNm

control of the vertical load on the cross-arm

Vz = 6.8 kN, Hy = 10.1 kN ≈ 10.42 kN

za ″a″ = ″b″ = 1.20 m dop Vz = 7.7 kN > 6.8 kNm

za ″c″ = 1.45 m dop Vz = 5.7 kN < 6.8 kNm

THE LOWER CROSS-ARM IS TO BE REINFORCED BY STAYS (OR PROPS)

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

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5. RECOMMENDED SELECTION OF TOWERS

5. 1. MOST COMMON STRUCTURES AND CROSS SECTIONS FOR NON-INSULATED CONDUCTORS

IN DIFFERENT CLIMATE CONDITIONS

The application tables defi ne the recommended types of towers and appropriate purpose of the tower in the route, for

certain conductor cross sections and specifi c max. working stress, conventional shapes of tower head type and when

used in diff erent climate conditions,. For suspension towers the allowed wind span is stated (semi-sum of the adjacent

spans), as also for the tension towers the allowed route deviation angle is present. Towers are selected based on the

most appropriate wind span relevant for the construction of the tower, and the allowed electric span.

Electric spans defi ned in tables refer to use of post type isolators (string 0.00m), on the adjacent towers with equal spans

of conductor suspension i.e. equal tower head type. Actual electric spans should be precisely defi ned and controlled

depending on the suspension equipment and head forms of adjacent towers.

The working stress of conductors does not infl uence the admissible wind spans for suspension tower structures. Still

it conditions the required tower height (infl uence on the conductor sag) and the possibility of using the tower in case

of exceptional load (infl uence on the breaking strength). The allowed wind spans stated for conductor suspension sets

are equal for a specifi c tower head type, conductor cross section and basic wind load without regard to the quantity of

the conductor working stress.

The allowed sum of vertical forces relates to vertical load of conductors and suspension equipment and electrical

devices (disconnectors, etc.) placed on the tower.

ELEMENTS DEFINED BY THE TOWER HEAD TYPE MARK

head type: G, D, J, B, T

JU, BU - with earth wire

upper cross-arm length: 1 - 95 cm

2 - 120 cm

3 - 145 cm

4 - 160 cm

distance between upper cross-arms, i.e.

between the top and the upper cross-arm: 1 - 85 cm

2 - 170 cm

3 - 255 cm

4 - 340 cm

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TOWER HEAD TYPE

- all measures are in centimetres

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5. 2. CONDUCTOR SUSPENSION SETS

CONDUCTORS Al/č 50/8 mm2

BASIC WIND LOAD

W = 500 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 107 152 115 137 185 206 165 260 72 165 260

1,6 89 126 96 114 154 171 137 216 60 137 216

2,5 73 104 79 94 128 142 114 179 50 114 179

dopΣV

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

315 330 350 320 330 170235195180

265215200

10,6 NAL2 9 – 15 satisfi es all stated electric spans

CONDUCTORS Al/č 50/8 mm2

BASIC WIND LOAD

W = 600 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 105 149 113 134 182 201 162 254 70 162 254

1,6 87 124 94 112 154 168 134 212 59 134 212

2,5 72 102 78 93 125 139 111 175 49 111 175

dopΣV

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

250 260 270 250 260 130190157145

220170155

10,6 NAL2 9 – 15 satisfi es all stated electric spans 185 200 225

13,6 NAP2 9 – 15 satisfi es all stated electric spans 430

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CONDUCTORS Al/č 50/8 mm2

BASIC WIND LOAD

W = 750 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 102 146 111 131 178 197 158 249 69 158 249

1,6 85 121 92 110 148 164 132 207 57 132 207

2,5 71 100 76 91 122 136 109 172 48 109 172

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

185 195 205 185 195130205100

145115105

165130115

10,6 NAL2 9 – 15 satisfi es all stated electric spans 160 180

13,6 NAP2 9 – 15 satisfi es all stated electric spans 335

CONDUCTORS Al/č 50/8 mm2

BASIC WIND LOAD

W = 900 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 101 144 109 130 175 195 156 246 68 156 246

1,6 84 120 91 108 146 162 130 205 57 130 205

2,5 70 99 75 89 121 134 107 169 47 107 169

Dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

190154140

145

220170155

190150120

205160130

1058060

1159065

13510070

10,6NAL2 9 11 – 15

210 225 235 210265225

115145125

165140

13,6NAP2 9 11 – 15

satisfi es all stated electric spans 240 275

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CONDUCTORS Al/č 50/8 mm2

BASIC WIND LOAD

W = 1100 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1.0 100 142 108 128 173 192 154 243 67 154 243

1.6 83 118 90 107 144 160 128 202 56 128 202

2.5 69 98 74 88 119 132 106 167 46 106 167

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

14511555

15512055

16512560

145110

155120

8055–

9060–

10070–

10,6 NAL2 9 – 15 160 170 180175155

190165

9545

11050

12565

13,6NAP2 9 – 13 15

satisfi es all stated electric spans 340 150190165

220185

8,0ZAE2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 1300 N/m2)**

195140

225145

10,0ZAH2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 1300 N/m2)**

310260

360300

* => Tower type NAH2 with cross-arm length 1.45 m (J21, J22, B) and 1.6 m (G4), does not satisfy the

required mechanical resistance and stability requirements in case of exceptional load i.e. in case of

conductor breaking.

** => Allowed wind spans are defi ned for the higher wind area due to the fact that towers have over 15 m.

For the defi ned wind it is also necessary to use adequate electric spans.

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CONDUCTORS Al/č 70/12 mm2

BASIC WIND LOAD

W = 500 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 110 156 119 142 155 212 170 268 74 170 268

1,6 93 132 100 119 131 179 143 226 62 143 255

2,5 77 110 83 99 109 149 120 188 52 120 188

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

260 270 285 260 270170145140

190160150

210175160

10,6NAL2 9 11 – 15

satisfi es all stated electric spans260235

CONDUCTORS Al/č 70/12 mm2

BASIC WIND LOAD

W = 600 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1.0 108 153 116 138 187 207 166 262 72 166 262

1.6 91 129 98 116 157 175 140 220 61 140 220

2.5 76 107 82 97 131 146 117 184 51 117 184

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

200 210 225 200280230220

140115110

155125115

180140125

10,6NAL2 9 11 – 15

satisfi es all stated electric spans330300

160 175210190

13,6NAP2 9 11 – 15

satisfi es all stated electric spans 340

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CONDUCTORS Al/č 70/12 mm2

BASIC WIND LOAD

W = 750 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 105 149 113 135 182 202 162 255 71 162 256

1,6 88 126 95 114 154 170 137 215 60 137 215

2,5 74 105 80 95 128 142 114 179 50 114 179

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

150 160225180165

195160150

210170160

801209585

13510595

10,6NAL2 9 11 – 15

satisfi es all stated electric spans

240 220 235 115140125

160140

13,6NAP2 9 11 – 15

satisfi es all stated electric spans 230 260

CONDUCTORS Al/č 70/12 mm2

BASIC WIND LOAD

W = 900 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 103 147 111 133 179 199 160 251 70 160 251

1,6 87 124 94 112 151 168 134 212 59 134 212

2,5 73 103 78 93 126 140 112 177 49 112 177

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m) (wind span)

8,0 9NAH2* 11 13

155125115

165130120

180140125

155125100

165130105

856550

957550

1108055

10,6NAL2 9 11 – 15

170 165220195

190170

205180

10595

115100

135115

13,6NAP2 9 11 – 15

satisfi es all stated electric spans 190 220

8,0ZAE2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 1300 N/m2)**

200160

225180

10,0ZAH2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 1300 N/m2)**

365295

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CONDUCTORS Al/č 70/12 mm2

BASIC WIND LOAD

W = 1100 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 102 145 110 131 177 196 157 248 69 157 248

1,6 86 122 92 110 149 165 132 208 58 132 208

2,5 72 102 77 92 124 138 110 174 48 110 174

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

1209045

1259545

13510550

12090–

13095–

6545–

7050–

8055–

10,6NAL2 9 11 – 15

145130

155135

165145

145120

155135

8035

9040

10045

13,6NAP2 9 – 13 15

satisfi es all stated electric spans155135

175150

8,0ZAE2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 1300 N/m2)**

290220

140110

160115

180120

10,0ZAH2 9 (11 – 21)**

satisfi es all stated electric spans (W = 1300 N/m2)**

270225

295255

* => Tower type NAH2 (for all head types) and tower NAL2 with cross-arm length 1.6 m does not satisfy the

required mechanical resistance and stability requirements in case of exceptional load i.e. in case of

conductor breaking.

** => Allowed wind spans are defi ned for the higher wind area due to the fact that towers have over 15 m. For

the defi ned wind it is also necessary to use adequate electric spans.

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

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CONDUCTORS Al/č 95/15 mm2

BASIC WIND LOAD

W = 500 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 108 188 120 152 216 243 204 321 89 204 321

1,6 92 160 102 129 184 207 174 273 76 174 273

2,5 77 134 86 109 155 174 146 230 64 146 230

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

220 230 245 220275245235

120165135130

185150140

10,6NAL2* 9 11 – 15

satisfi es all stated electric spans 310 170205180

230210

13,6NAP2 9 11 – 15

satisfi es all stated electric spans 300 325 350

CONDUCTORS Al/č 95/15 mm2

BASIC WIND LOAD

W = 600 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 104 183 116 147 210 236 199 313 87 199 313

1,6 88 155 99 125 179 201 169 266 74 169 266

2,5 74 131 83 105 150 169 142 224 62 143 224

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

220185175

180250205195

215185175

230195185

90135110100

155120110

10,6NAL2* 9 11 – 15

satisfi es all stated electric spans 260 135165150

190165

13,6 NAP2 9 – 15 satisfi es all stated electric spans 267 300

8,0ZAE2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 750 N/m2)**

310240

10,0ZAH2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 750 N/m2)**

480380

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DALEKOVOD - PROJEKT

30

CONDUCTORS Al/č 95/15 mm2

BASIC WIND LOAD

W = 750 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 99 178 111 142 204 229 193 304 84 19 304

1,6 85 151 95 121 173 195 164 259 72 165 259

2,5 71 127 80 101 146 164 138 218 60 138 218

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2 11 13

165140130

180145135

195155145

165135130

180145135

90 75 70

1058075

1159080

10,6NAL2* 9 11 – 15

190 200235215

205190

225200

100125 110

145125

13,6 NAP2 9 – 15 satisfi es all stated electric spans 210 235

8,0ZAE2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 900 N/m2)**

380310

190155

210170

240195

10,0ZAH2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 900 N/m2)**

380320

CONDUCTORS Al/č 95/15 mm2

BASIC WIND LOAD

W = 900 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21J22 B21 B22 B23

1,0 96 174 108 138 199 224 190 299 83 190 299

1,6 82 148 92 118 170 190 161 254 70 161 254

2,5 69 125 78 99 143 160 136 214 59 136 214

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

135105100

145115105

155120110

13510585

14511590

755540

806545

957050

10,6NAL2 9 11 – 15

165150

155190165

165145

175155

9080

10090

11695

13,6 NAP2 9 – 15 satisfi es all stated electric spans 170 195

8,0ZAE2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 1100 N/m2)**

310295

155120

170140

195155

10,0ZAH2 9 – 15 (17 – 21)**

satisfi es all stated electric spans (W = 1100 N/m2)**

280220

320265

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

31

CONDUCTORS Al/č 95/15 mm2

BASIC WIND LOAD

W = 1100 N/m2

Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

ELECTRIC SPANS (m)

HEAD TYPE

ADDITIONAL LOAD

G2 G4 D11 D21 D12 D22J11

J21 J22 B21 B22 B23

1,0 94 172 106 135 195 220 187 294 81 187 294

1,6 80 146 90 115 166 187 159 250 69 159 250

2,5 67 123 76 97 140 157 134 210 58 134 210

dop∑V

z

(kN)tower type

ALLOWED SEMI-SUM OF ADJACENT SPANS (m)(wind span)

8,0 9NAH2* 11 13

1008040

1108540

1159040

–––

–––

55 60–––

.10,6NAL2* 9 11 – 15

125110

135120

145125

125110

135115

7030

7535

8535

13,6NAP2 9 – 13 15

210 230 250 220 235125105

135115

155130

8,0ZAE2 9 – 15 (17 – 21)**

satisfi es all stated electric spans

(W = 1300 N/m2)**

255

185

235

180

255

185

120

90

140

95

165

100

10,0ZAH2 9 – 15 (17 – 21)**

satisfi es all stated electric spans(W = 1300 N/m2)**

220190

265220

* => Tower type NAH2 (for all head forms) and tower NAL2 with cross-arm length over 1.20 m does not

satisfy the required mechanical resistance and stability requirements in case of exceptional load

i.e. in case of conductor breaking.

** => Allowed wind spans are defi ned for the higher wind area due to the fact that towers have over 15

m. For the defi ned wind it is also necessary to use adequate electric spans.

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5. 3. CONDUCTOR TENSION SETS

CONDUCTORS Al/č 95/15 mm2Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

TOWER HEAD TYPE TOWER TYPETHE PURPOSE

OF THE TOWER

IN THE TRANSMISSION LINE ROUTE

ALLOWED WIND SPANS FOR THE

STRUCTURE(CONTROL ELECTRIC SPANS)

aw

=(l1+l

2)/2 (m) W (N/m2)

G2, G4

(G1, G3)

ZAL2Ka 90°

260≤ 1100KR 120° – 180°

ZAJ2 KR 145° – 180° 200

D11, D21

(D31, D41)

ZAL2Ka 90°

320 ≤ 1100KR 120° – 180°

ZAJ2 KR 130° – 180°160 1100

210 ≤ 900

D12, D22

(D32, D42)

ZAL2Ka 90°

370 ≤ 1100KR 120° – 180°

ZAJ2

Ka 90° i

KR 120° – 124°

130 1100

180 900

230 ≤ 750

KR 125° – 129°

160 1100

220 900

280 ≤ 750

KR 130° – 139°200 1100

260 ≤ 900

KR 140° – 180° 270 ≤ 1100

J11, J21

(J21*)

ZAL2Ka 90°

320 ≤ 1100KR 120° – 180°

ZAJ2

KR 130° – 134°165 1100

220 ≤ 900

KR 135° – 180°200 1100

260 ≤ 900

J22

(J22*)

ZAL2Ka 90°

380 ≤ 1100KR 120° – 180°

ZAJ2

KR 125° – 129°

170 1100

185 900

240 ≤ 750

KR 130° – 139°

210 1100

270 900

340 ≤ 750

KR 140° – 180°280 1100

350 ≤ 900

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

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CONDUCTORS Al/č 95/15 mm2Maximum conductor working stress, σ = 95 N/mm2

Conductor suspension sets

TOWER HEAD TYPE TOWER TYPETHE PURPOSE

OF THE TOWER

IN THE TRANSMISSION LINE ROUTE

ALLOWED WIND SPANS FOR THE

STRUCTURE(CONTROL ELECTRIC SPANS)

aw

=(l1+l

2)/2 (m) W (N/m2)

B21

(B31)

ZAM2 KR 155°-180° 230≤ 1100

ZAM2

σ = 70 N/mm2

Ka 90° iKR 120°-180°

150

B22

(B32)

ZAM2 KR 150°-180° 250 ≤ 1100

ZAM2

σ = 80 N/mm2

Ka 90° iKR 120°-180°

130 110

160 900

200 ≤ 750

ZAL2 R 180° 300 ≤ 1100

B23

(B33)

ZAM2 KR 125°-180°

135 1100

175 900

220 ≤ 750

ZAM2

σ = 80 N/mm2

Ka 90° iKR 120°-180°

170 1100

210 900

270 ≤ 750

ZAL2 KR 165°-180° 330 ≤ 1100

ZAL2

σ = 80 N/mm2 KR 125°-180°

140 1100

180 900

225 ≤ 750

Vertical forces must not exceed the allowed vertical forces for certain load scenarios and for specifi c cross-arm

lengths, as defi ned by the strength capacity table i.e. by the allowed load for a specifi c tower.

The defi ned wind spans allowed for the sharpest route deviation angle, is increased for other angles and can be

controlled according to the tower strength capacity table

Head types marked with * (J21*, J22*) are applied in cases when the torque at the basic load exceeds the values

from the strength capacity table. In this case the MT value relates to the length of the higher, and not lower

cross-arm.

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When place orders for towers it is necessary to state the required number of a certain type of towers, their height, as

also to required number of cross-arms.

Cross-arms are defi ned by a specifi c type of tower, by the head type and arrangement of conductors suspension on

the tower.

E.g.

For the transmission line route with suspension insulator strings, hanged over hinges, type of the head J21 and J22,

towers type NAL2 – 5 pieces and ZAE2 in the function of suspension tower – 1 pc., and the tension towers, head type

D21 and D22, tower type ZAJ2 – 2 pcs., and head type J21, tower ZAE2 – 1 pc., it is necessary to place the following

order:

Towers:

tower NAL2 – 13, 3 pcs.

tower NAL2 – 15, 2 pcs.

tower ZAE2 – 17, 2 pcs.

tower ZAJ2 – 11, 2 pcs

Konzole za nosivo zavješenje vodiča preko zastavica:

NAL2: 2 – 10 pcs.

J3 – 5 pcs.

ZAE2: J2 – 2 pcs.

J3 – 1 pc.

Cross-arms for tension of conductors over hinges:

ZAJ2: TOP – 2 psc.

D2 – 2 pcs.

G3 – 1 pc. (tap-off )

ZAE2: J2 – 2 pcs.

J3 – 1 pc.

For the structure (cross-arm, application of stays or props, auxiliary equipment girder) that is not covered by the

catalogue, it is necessary to deliver the request accompanied with relevant technical documentation, i.e. description

based on which it is possible to make a proposal and prepare an off er for the elements required.

The standard corrosion protection of the structures is performed by hot dip galvanizing for normal atmospheric

conditions. Still it is also possible to deliver structures without corrosion protection or with additional protection

(painted), and this is necessary to be clearly stated when placing your order.

When taking over the structure, the client is delivered the building blueprints and documentation proving the quality

of the material, structure and corrosion protection of both the installed elements and of the structure as whole,

according to the static calculation of the tower.

6. ORDERING INFORMATION AND STRUCTURE TAKEOVER

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

35

DETAILS OF THE CROSS-ARM TOP

SUSPENSION TOWERS

Standard suspension over the post type insulator or shackles

Standard suspension sets over hinges(delivery with note - suspension sets over hinges)

PLATES FOR SINGLE SUSPENSION

(Delivery without notes)

ADDITIONAL PLATES FOR DOUBLE SUSPENSION

(delivery with note - for double suspension)

TENSION TOWERSStandard suspension over hinges

(Delivery without notes)

FOR ALL CROSS-ARMSWhen placing orders for cross-arms (for suspen-sion over “V” extension links or isolators, that is for suspension equipment where the standard elements are not adequate) it is necessary to ad-ditionally state the suspension mode and type, i.e. the suspension equipment catalogue number

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The foundation part of the structure is placed within the foundation excavation, it is centred and fi xed, and then the

concrete is cast in the foundations. Further assembly is made after the concrete solidifi es. The structure can be mounted

element by element (one element at the time), in parts (sections) or in one piece (complete).

Sections of the towers are composed of main legs of max. length 6m connected with diagonals, and the same section

is used for towers of diff erent heights without requiring additional works on the structure as such. In this way the

storage (number of positions) and assembly of towers is simplifi ed. It makes possible to very simply use them on

diff erent locations in case the existing tower is to be disassembled, as also makes possible to use then for lower heights,

that is the foundation section can be used for both equal and for higher towers.

7. ASSEMBLING THE STRUCTURE

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

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SE

CT

ION

1

SE

CT

ION

1

SE

CT

ION

2

SE

CT

ION

2S

EC

TIO

N 3

FO

UN

DA

TIO

N S

EC

TIO

N

FO

UN

DA

TIO

N S

EC

TIO

N

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38

8. FOUNDATIONS

The foundation dimensions are recommended for each type of tower, according to the nominal load and height of the

tower in question. Foundations are calculated according to the Sulzberger method for several diff erent characteristics

of bearing, non-aggressive and stable soil.

Soil characteristics are established according to the abovementioned Regulation for Overhead Power-lines obtained

by geo-mechanical tests used in designing transmission lines over many years of experience for:

gravel and gravel-sand soils, sandstone, fl ysch, etc.

free of groundwater, σdop = 250 kN/m2

with groundwater, σdop = 200 kN/m2

clay and clay-sand soils

free of groundwater, σdop = 150 kN/m2

with groundwater, σdop = 120 kN/m2

for foundations on solid rock the strength capacity, ódop > 500 kN/m2 the minimum dimensions are

conditioned by the geometry of the foundation, tower structure and method used in making the foundations.

The foundation is made for simple structure as a not-reinforced concrete block without shoe, into which is placed

the foundation part of the structure. To insure simpler installation in cases of deep foundations, the construction of

foundation extensions is proposed, in this case it is possible to use smaller profi les than the dimensions of tower main

legs. It is required to use concrete, pressure strength class C20/25, that does not lose strength by ageing.

By standard the foundation is made with crown d = 20 cm over the ground. If required (fl ood water, increased security

height of the conductor, construction on inclined plateau, etc.) the structure is made with appropriate heightening of

the foundations.

For soils of lower/poorer characteristics and conditions, deviating from the defaulted ones, as also for diff erent

technology used (e.g. shallow foundations), the adequate foundations shall be recalculated. In this case it is also

necessary to take into consideration the standard length of the foundation part of the structure (L) characteristic for

each tower, or consult the manufacturer of the structure for possible manufacturing of customised foundation section

(e.g. for anchoring screws).

l => useful length of the foundation extension

L => foundation part of the structure

d ≥ 20 cm (as required)

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STEEL LATTICE TOWERS FOR 10, 20 AND 35 kV TRANSMISSION LINES

39

SOIL CHARACTERISTICS FOR THE RECOMMENDED FOUNDATION DIMENSIONS

SOIL CLAY-SANDGRAVEL-SAND, FLYSCH,

SANDSTONE, etc.ROCK

GROUND WATERS NO YES NO YES NO

min σdop

(kN/m2) 150 120 250 200 >500

min γ (kN/m3) 18 9 18 9 19

min Ct (kN/cm3) 0.07 0.04 0.11 0.06 0.17

min b (degrees) 10 7 14 11 20

min mb

0.40 0.35 0.4 0.35 0.45

ROCK LOOSE SOIL AND SOILS IN GROUND WATERS

EX

CA

VA

TIO

N P

ER

IME

TE

RE

XC

AV

AT

ION

PE

RIM

ET

ER

EX

CA

VA

TIO

N P

ER

IME

TE

R

EX

CA

VA

TIO

N P

ER

IME

TE

R

EX

CA

VA

TIO

N P

ER

IME

TE

R

EX

CA

VA

TIO

N P

ER

IME

TE

R

EX

CA

VA

TIO

N P

ER

IME

TE

R

EX

CA

VA

TIO

N P

ER

IME

TE

R

ANGLE TENSION TOWER, KRα - line route deviation angle

END TOWER, Ka 90º

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President of the Management Board: Davor Đurđević • Project Designer: Branka Podobnik • Collaborator: Tomislav StojčevićDALEKOVOD-PROJEKT d.o.o. • design, control, consulting and engineering • 10000 Zagreb, Marijana Čavića 4

e-mail: [email protected] • Tel: +385 1 24 11 100 - Operator • Fax: +385 1 24 52 381

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Publisher: DALEKOVOD-PROJEKT d.o.o., 2010.e-mail: [email protected]

Steel lattice towers for 10, 20 and 35 kV transmission lines

INSTRUCTIONS FOR DEPLOYMENT OF TOWERS

www.dalekovod.com

PROJEKT

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