There are two specific types of pole structure, namely suspension structures, which suspend transmission lines and tension structures, which maintain the tension of lines between angle structures.

This photo refers to our 110KV twin circuit suspension poles, with technical specification as follow:

Remark: above technical data only references for our client, we can design every type for our overseas clients.

MEGATRO is a full service engineering company with a global reputation for delivering excellence and innovation in power transmission, transformation, distribution, and telecommunications systems. Our MEGATRO provide and design this type 110KV twin circuit suspension poles mainly for our overseas client. Since 2004, MEGATRO focus mainly international market and had export many kind of transmission structures to overseas clients. MEGATRO has been manufacturing lattice transmission tower & tapered steel poles for lighting, traffic control, communication and utility applications. MEGATRO pioneered the development of transmission tower, telecom tower, substation, and other steel structure and was also at the forefront in the design of Transmission tower.

Over 10 years of experience and innovation in engineering, designing and building towers has evolved MEGATRO into its current form:
lFull Turn-Key provider including site acquisition, engineering services, manufacturing,   field services-DAS, tech services, value added reseller and monitoring, maintenance and network ownership
lSpecialize in developing supplying and building wireless and wired networks and in-building telecommunications systems, as well as energy infrastructure
lSingle source from Design to System Integration
lTop quality, ISO 9001 registered
A complete selection of towers including self-support, lattice steel tower, monopoles and guyed towers, form custom-designed radar towers to broadcast towers and energy infrastructure. MEGATRO carries a variety of related products including fall protection, transmission lines, antennas, obstruction lights, and accessories, and other products if client need, MEGATRO also tailored product as per client condition.
MEGATRO mainly design all kinds of towers and posts for:
a.Telecoms
b.Power transmission
c.TV and Radio Broadcast
d.Roads and City Development
e.Wind energy solution
f.Steel structure and workshop

Our complete selection of towers includes:
a.Self-supporting
b.Monopoles
c.Guyed towers
d.Custom-designed radar towers
e.Broadcast towers
f.Power transmission

MEGATRO also designs and manufactures tower related products including:
a.Fall protection
b.Antenna brackets
c.Other accessories if needed by clients

Today, with over 10 years of experience and our commitment to excellence, MEGATRO remains an industry leader in the manufacture and design of steel tubular & angular & monopole structures for all Highway, Municipal, Custom, telecom, lighting and electric Utility applications. MEGATRO has a complete staff of professional engineering personnel trained in the PLS Pole program and three different manufacturing processes for producing steel towers, poles and other supports. We utilize the latest versions of PLS-CADD, PLS-POLE, TOWER, AutoCAD and other CAD software.

The structure shall be designed according to load combinations given as per IEC 61936-1 and as illustrated below:
Normal loads
1 Dead weight load
2 Tension load
3 Erection load
4 wind load
 
Exceptional loads
1 Switching forces
2 short-circuit forces
3 Loss of conductor tension
4 Earthquake forces

Moreover, MEGATRO is fully equipped and qualified to carry out Design Engineering services which includes:
√ Overhead Transmission line steel tower & Telecom steel tower
   Basic Design and Analysis
√ Shop Erection Drawings
√ As-Built Drawings

MEGATRO performs in-house design activities specializing in electrical overhead transmission &telecom tower steel works, which include wind and earthquake loading, static analysis, stress analysis by finite element methods and fatigue. Our Engineering Department is boasting of highly qualified engineering who are conversant with international codes and standards. The work is carried out with extensive use of CAE/CAD via a large of computer network. The computer hardware & drafting software are liked to the CNC workshop equipment for downloading of information thereby eliminating error and saving valuable production time. 

Besides, MEGATRO is one of the few manufactures who assemble a face of 110KV twin circuit suspension poles. This attention to quality may not be the cheapest process but it does insure every tower meets our high standards of quality. And it helps to reduce on-site construction cost due to mismatched assemblies. After fabrication all 110KV twin circuit suspension poles are delivered to the galvanizing facility to be Hot DIP Galvanized. Towers are processed through the facility by Caustic Cleaning, Pickling, and then Fluxing. These strict procedures insure years of maintenance free towers. MEGATRO' 110KV twin circuit suspension poles systems can accommodate a variety of cross-arm. MEGATRO also offers a wide variety of accessories and mounts.

Other information:
Availability size: Based on the customer's requirements.
Material: Chinese material or as per clients requirement
Steel grades
Tower legs: Chinese steel Q345B, which equivalent to ASTM A572 GR50
Other webs, bracing and not stress plate and angle steel: Chinese Q235B, which equivalent to ASTM A36
Plates: Chinese steel Q345B, which equivalent to ASTM A572 GR50
Bolts: Bolt quality shall be Chinese Class 6.8 and 8.8, as per our Chinese standard, or ISO 898 standard or ASTM A394 type 0,1,2,3 requirements
The anti-theft bolts shall be Huck bolt Fasteners or approved equivalent.  The fasteners shall be manufactured from high tensile steel A242 or equivalent and hot-dip galvanized in accordance with ASTM specification A153 and A394.

Fabrication standard: Chinese Standard or other standard which client accepted
A) Dimension and tolerance for angle are according to GB/T1591-1994, similar to EN 10056-1/2
B) Hot dip galvanization in accordance with GB/T 13912-2002, which similar to ASTM A 123
C) The welding will be performance in accordance with AWS D1.1 or CWB standard
D) All fastener galvanization conform to ASTM A153 requirements.

Package: Both parties discuss before delivery
Port of Loading: Qingdao Port
Lead Time: One month or based on the customer's needs ( for time being our capacity about 5000 tons one month, and can meet client requirements)
Minimum order: 1 set

General Fabrication Requirements
Here is general fabrication requirements for our transmission tower; however, both parties must discuss all drawings and confirm all shop drawings, technical specification, and which standard to conform.
Before mass production, we must received all signed approved shop drawings and technical documents from our client.

Our Fabrication shall be in strict accordance with detail Drawings prepared by the Contractor and approved by the Engineer.  Fabrication shall begin after the approval of the shop assembly and tests.
 
Shearing
 
Shearing and cutting shall be performed carefully and all portions of the work which will be exposed to view after completion shall be finished neatly.  Manually guided cutting torches shall not be used.

All material over 13 (or 12) mm thick shall be cold sawn or machine flame cut.
Cropping or shearing shall be allowed for material thickness of 13 mm or less.
Flame cutting of high yield steel shall be preceded by a slight preheat operation by passing the cutting flame over the part to be cut.
All flame-cut edges shall be ground clean. 
 
Bending

Bending shall be carried out in such a manner as to avoid indentation and surface damage. All bending over 5o, or high yield steel, shall be performed while the material is hot.

Welding

No welding shall be done unless prior approval has been obtained from the Engineer.
Welding shall not be allowed at tower attachment points for conductor, shield-wire, insulators or associated assemblies or brackets.

Sub-punching

All holes in structural steel less than 10 mm thickness may be punched to full size unless otherwise noted on the approved Drawings.  Holes shown on the Drawings as drilled holes and all holes in structural steel 10 mm or more in thickness and tension members of cross-arms shall be drilled or sub-punched and reamed.

All holes shall be clean cut and without torn or ragged edges.  All burrs resulting from reaming or drilling shall be removed.  All holes shall be cylindrical and perpendicular to the member.

Where necessary to avoid distortion of the holes, holes close to the points of bends shall be made after bending.

Punching

For punching to full size, the diameter of the punch shall be 1.0 mm larger than the nominal diameter of the bolt, and the diameter of the die shall not be more than 1.5mm larger than the diameter of the punch. For sub-punching, the diameter of the punch shall be 4 mm smaller than the nominal diameter of the bolt, and the diameter of the die shall be not more than 2 mm larger than the diameter of the punch.  Sub-punching for reamed work shall be such that after reaming no punch surface shall appear in the periphery of the hole.

Hole Size

Where holes are reamed or drilled, the diameter of the finished hole shall be not greater than the nominal diameter of the bolt plus 1.0 mm.

Accuracy

All holes shall be spaced accurately in accordance with the Drawings and shall be located on the gauge lines.

The maximum allowable variation in hole spacing from that indicated on the Drawings for all bolt holes shall be 0.8 mm.

Fabrication Tolerances

A specification for tolerances shall be submitted for approval by the Engineer prior to commencement of fabrication.

Bolt List

A complete list of bolts showing their lengths and the members, which they are to connect shall be given on the erection diagrams.

Locking Devices

Locking devices for tower bolts will not be required, but point punching shall be performed.

Anti-theft Fasteners
 
Appropriate anti-theft fasteners for example Huck-bolting shall be applied on all the towers up to the level of anti-climbing devices, to prevent theft of tower members.
Piece Marks

All pieces shall be stamped before galvanizing with the piece marks shown on the erection Drawings, with the marking not less than 20 mm high placed in the same relative location on all pieces.  The marking shall be plainly visible after galvanizing.

Galvanizing

All material shall be hot-dip galvanized after fabrication in accordance with the latest revision of GB/T 13912-2002 or ASTM Specification A 123.

Material that has been rejected because of bare spots or other coating defects shall either be stripped and re-galvanized, or the uncoated areas shall be recoated by an approved method.

All plates and shapes which have been warped by the galvanizing process shall be straightened by being re-rolled or pressed.  The material shall not be hammered or otherwise straightened in a manner that will injure the protective coating.

Approval shall be secured from the Engineer if galvanizing is done outside of the Contractor's plant.

All galvanized steelwork shall be protected against white storage stain by using an approved dichromate solution treatment immediately following galvanizing.

APPLICABLE STANDARD AND CODES
All towers manufactured and design shall be generally in accordance with latest revision of the following standards except where specifically directed otherwise.
General
IEC 60826    -  Design criteria of overhead lines
IEC 60652    -  Loading tests on overhead line structures
ISO 1459    -  Metallic coatings - Protection against corrosion by Hot Dip Galvanizing
ISO 1461    -  Hot dip galvanized coatings on fabricated iron and steel articles
ISO 12944    -  Paint coatings, corrosion protection, and structural steelwork
ISO 898-1    -  Mechanical properties of fasteners. Part 1-Bolts, Screws and studs
ISO 630    -  Structural Steels - plates, wide flats, bars, sections and profiles
ISO 657    -  Hot rolled structural steel plates tolerances on dimensions and shape
ISO 7411    -  Hexagon Bolts for high strength structural bolting with large width across flats
ISO 657-5    -  Hot rolled Structural Steel Sections equal and unequal leg angles
ISO 7452    -  Hot rolled structural steel plates tolerances on dimensions and shape
BS EN 50341-1  - Overhead electrical lines exceeding AC 45kV –General Requirements
BS 8004    -  Code of Practice for Foundations
BS 8110    -  Structural use of concrete
ANSI10-97    - Design of latticed steel transmission structures
IEC 60050 (151)                         International Electro-technical Vocabulary
                                       Part 51 Electrical and Magnetic Devices
IEC 60050 (601)                      Chapter 601: Generation, transmission and distribution of electricity-General
IEC 60050 (601)                    Chapter 601: Generation, transmission and distribution of electricity-Operation
IEC 60059                              IEC standard current ratings

Chinese Standard

American Standards:

DIN VDE 0101                       -  Isokeraunic Level
VDE 0201                              - Climatic and environmental   conditions
CVDE 0210                           -  Minimum safety factors under    simultaneous working loads
ISO R898 Mechanical Properties of Fasteners
BS EN ISO 1461:1991 - High dip galvanized coatings on fabricated iron and steel articles. Specifications and standards
A) BS 5950: Welding Terms And Symbols
B) BS 729: Hot - Dip Galvanised Coating On Iron And Steel Articles
C) BS 2901: Filler Rods And Wires For Gas Shielded Arc Welding: Part 1 Ferritic Steels
D) BS 3692: ISO Metric Precision Hexagon Bolts, Screws And Nuts
E) BS 4360: Weldable Structural Steel
F ) BS 5135: Metal - Arc Welding Of Carbon And Carbon Manganese Steel
G) BS 5950: Part 1: Code Of Practice For Loading Latticed Tower & Masts
Part 2: Guide To The Background And Use Of Part 1"Code OF Practice For Loading"
Part 3: Strength Assessment of Members
H) DD 133 (1986): Code Of Practice For Loading Latticed Tower & Masts
I) BS 4592 (1987): Part 2: Specification For Expanded Metal Grating Panels
J) BS 4592 (1977): Code Of Practice For Protective Coating Of Iron And Steel Structure Against Corrosion
K) BS 4190: Bracing & Flanged Bolts
L) BS 4190: Rolled Steel sections, Flats & Plates

If any special requirement, we can design and discuss with client.