Basic Info.
Model NO.
MGP-steel structure
Trademark
MEGATRO
Origin
Shandong, China
HS Code
73089000
Production Capacity
4000 Sets/Year
Product Description
MEGATRO railway steel structure
Description
MEGATRO had talented experts and design engineer in this field more than fifteen years. line Railway mast towers design must consider traffic and environment with power transmission project harmony together.
After fabrication all railway mast tower 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 railway steel structure systems can accommodate a variety of cross-arm. MEGATRO also offers a wide variety of accessories and mounts.
Availability size: Based on the customers requirements.
Material: Chinese material or as per clients requirement
Package: both parties discuss before delivery
Terms of Payment: L/C, T/T
Minimum Order Quantity: 10tons
Port of Loading: Qingdao Port
Lead Time: one month or based on the customers needs
Performance Standard
Besides conform to the drawing and design, the materials and fabrication of tower components shall conform to the Chinese Standard or other standard which clients can accept.
MEGATRO is professional manufacturer for railway mast towers and supports. We had talented experts and design engineer in this field more than fifteen years. Railway mast towers design must consider traffic and environment with power transmission line project harmony together.
After fabrication all railway mast tower 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'S railway steel structure systems can accommodate a variety of cross-arm. MEGATRO also offers a wide variety of accessories and mounts.
Availability size: Based on the customers requirements.
Material: Chinese material or as per clients requirement
Package: both parties discuss before delivery
Terms of Payment: L/C, T/T
Minimum Order Quantity: 1ton
Port of Loading: Qingdao Port
Lead Time: one month or based on the customers needs
Performance Standard
Besides conform to the drawing and design, the materials and fabrication of tower components shall conform to the Chinese Standard or other standard which clients can accept.
This photo refers to our STREET LIGHT POLE , it is widely used in our Chinese market. Some of technical features of this tower as follow:
Here is the design strength of Chinese tower steel
3 Here is the design strength of our Chinese tower bolts
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 railway steel structure mainly for our Chinese and 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:
MEGATRO mainly design all kinds of towers and posts for:
Our complete selection of towers includes:
MEGATRO also designs and manufactures tower related products including:
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 railway steel structure , 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 railway steel structures are delivered to the galvanizing facility to be Hot DIP Galvanized.
Except otherwise specified elsewhere in the specification, the surface treatment and corrosion protection for all metal parts shall be in conformity with the latest revision of the standards listed below:
ASTM A 123 zinc (hot-dipped galvanized) coating on iron and steel products
DIN 55928 Protective painting of steel structure instructions
DIN 55945 Painting materials-Notions
DIN 18363 Paint work-Buildings
DIN 18364 Surface protection work for steel
DIN 53210 Determination of rust degree
DIN 55151 Determination of adhesion
ISO4628/3 Determination of rust penetration
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 Huckbolt 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.
Step bolt:
Each steel tower shall be provided with step bolts on one of the legs for single circuit steel tower and on two diagonally opposite legs for double circuit steel tower from approximately 2.5 meters above ground level to the cross arm and from thereon to each ground wire peak. Step bolts shall be furnished for each leg extension in an amount of 25% of the step bolt holes. These bolts shall not be less than 16 mm or 3/4" diameter, double nut type, 18 cm or 7" long with 35 mm or 1 5/8"diameter, symmetrical head, two hexagon nuts and spring washers, spaced not more than 45 cm or 18" apart. Each bolt shall withstand without permanent deformation a vertical load of at least 137 kg applied at the bolt head. If any technical specification, we will discuss with our client and confirm before mass production.
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.
Preparation for Shipping and Storage
To facilitate segregation of steel tower parts at the stockyard and to maximize the efficiency of erection, packaging of steel towers shall be as follows:
All steel tower parts, including stub angles, plates and steel tower parts member shall be color coded. The color code shall be painted on both ends of the steel tower parts for all angular members and around the edges for plates. The color codes shall be as specified in the Technical Data Sheets. All stub angles shall be packaged per unit steel tower per type i.e., four (4) pieces per bundle.
All cleats including bolts and nuts with spring washers for stub angles shall be packaged per unit steel tower per type in wooden boxes with corresponding color code painted on all corners of the box.
All basic body steel towers shall be packaged per unit steel tower per type. Each package shall not exceed three (3) metric tons. The contents of each package per unit steel tower per type shall be identical for any succeeding unit type. The numbering of each package shall indicate steel tower type (basic), steel tower number and number of pieces included in the package.
Example:
MG -Basic/Steel tower No./Package No./Qty. in this package
MG -Basic/ 1 of 200/ 2/ 8
All bolts and nuts with spring washers shall be package in tin cans or wooden boxes per unit steel tower per type and numbered as follows:
Example:
MG Bolts (Basic)/Steel tower No./Package No./Quantity
All plates and gussets for the basic steel tower shall be package in wooden boxes per unit steel tower per type and numbered as follows:
Example:
MG Plates (Basic)/Steel tower No./Package No./Quantity
All body extension steel tower parts shall be package per unit steel tower per type. The weight of each package shall not be more than three (3) metric tons. The contents of each package per unit per steel tower shall be identical for any succeeding unit steel tower. The numbering of each package shall indicate the steel tower type and extension steel tower number, and number of pieces included in the package.
Example:
MG Body Ext./Steel tower No./Package No./Quantity
MG Body Ext./Steel tower No./Package No./Quantity
All bolts and nuts with washers and plates for the body extensions shall be packaged in wooden boxes per unit steel tower per type and numbered as follows:
Example:
MG Plates & Bolts/Steel tower No./Package No./Quantity
All steel tower parts/members shall be marked as indicated in the steel tower parts list. The markings shall be embossed, the size of which will be approved by the our client.
All package numbers for the steel tower shall be in label form. The size of the label shall be 5 cm x 10 cm. The label shall be waterproof and all letterings on the label shall be printed. This label shall be attached on every bundle of package. Each bundle or package shall have at least two (2) labels, each label is visible on each side of the bundle.
All bundle or packages for steel tower shall be properly strapped to avoid disintegration of the bundle when subjected to unnecessary impact. The strap shall be properly placed so that the breakage of one (1) or two (2) straps will not allow disintegration of the bundle or package.
Smaller pieces shall be bundled, with all the pieces in any bundle having the same mark.
All small pieces such as bolts and connections for ground wire and insulators shall be packed in boxes of not over 70 kg gross weight each. Bolts of different size or length shall be wrapped in separate sacks before boxing. Description, quantity, bolt size, and length shall be clearly marked on the outside of the sacks and boxes.
When specified in the Purchase Order, bundling and packaging shall be in lots for each individual structure. Boxes or other containers shall be clearly marked to indicate the type of steel tower for which the enclosed material is intended, and the quantity and marks or description of contents shall be shown on the outside.
Shipping shall be as specified by the Purchase Order and shall be in complete steel tower lots. All identifications shown on bundles, boxes or other containers shall be included on Contractor's shipping and packaging lists.
Description
MEGATRO had talented experts and design engineer in this field more than fifteen years. line Railway mast towers design must consider traffic and environment with power transmission project harmony together.
After fabrication all railway mast tower 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 railway steel structure systems can accommodate a variety of cross-arm. MEGATRO also offers a wide variety of accessories and mounts.
Availability size: Based on the customers requirements.
Material: Chinese material or as per clients requirement
Package: both parties discuss before delivery
Terms of Payment: L/C, T/T
Minimum Order Quantity: 10tons
Port of Loading: Qingdao Port
Lead Time: one month or based on the customers needs
Performance Standard
Besides conform to the drawing and design, the materials and fabrication of tower components shall conform to the Chinese Standard or other standard which clients can accept.
MEGATRO is professional manufacturer for railway mast towers and supports. We had talented experts and design engineer in this field more than fifteen years. Railway mast towers design must consider traffic and environment with power transmission line project harmony together.
After fabrication all railway mast tower 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'S railway steel structure systems can accommodate a variety of cross-arm. MEGATRO also offers a wide variety of accessories and mounts.
Availability size: Based on the customers requirements.
Material: Chinese material or as per clients requirement
Package: both parties discuss before delivery
Terms of Payment: L/C, T/T
Minimum Order Quantity: 1ton
Port of Loading: Qingdao Port
Lead Time: one month or based on the customers needs
Performance Standard
Besides conform to the drawing and design, the materials and fabrication of tower components shall conform to the Chinese Standard or other standard which clients can accept.
This photo refers to our STREET LIGHT POLE , it is widely used in our Chinese market. Some of technical features of this tower as follow:
Here is the design strength of Chinese tower steel
| Steel material | Anti-push, bending and press strength (N/mm2) | Anti-shear strength (N/mm2) | |
| Grade | Thickness or diameter (mm) | ||
| Q235 Steel | ≤16 | 215 | 125 |
| >16~40 | 205 | 120 | |
| >40~60 | 200 | 115 | |
| >60~100 | 190 | 110 | |
| Q345 Steel | ≤16 | 310 | 180 |
| >16~35 | 295 | 170 | |
| >35~50 | 265 | 155 | |
| >50~100 | 250 | 145 | |
| Q420 Steel | ≤16 | 380 | 220 |
| >16~35 | 360 | 210 | |
| >35~50 | 340 | 195 | |
| >50~100 | 325 | 185 | |
| Q460 Steel | ≤16 | 415 | 240 |
| >16~35 | 395 | 230 | |
| >35~50 | 380 | 220 | |
| >50~100 | 360 | 210 | |
3 Here is the design strength of our Chinese tower bolts
| Item | Grade | Anti-push strength (N/mm2) | Anti-shear strength (N/mm2) |
| Fastener for towers | 4.8 | 200 | 170 |
| 5.8 | 240 | 210 | |
| 6.8 | 300 | 240 | |
| 8.8 | 400 | 300 | |
| Anchor bolts | Q235 | 160 | / |
| Chinese 35 steel | 190 | / | |
| Chinese 45 steel | 215 | / |
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 railway steel structure mainly for our Chinese and 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:
- Full Turn-Key provider including site acquisition, engineering services, manufacturing, field services-DAS, tech services, value added reseller and monitoring, maintenance and network ownership
- Specialize in developing supplying and building wireless and wired networks and in-building telecommunications systems, as well as energy infrastructure
- Single source from Design to System Integration
- Top quality, ISO 9001 registered
MEGATRO mainly design all kinds of towers and posts for:
- Telecoms
- Power transmission
- TV and Radio Broadcast
- Roads and City Development
- Wind energy solution
- Steel structure and workshop
Our complete selection of towers includes:
- Self-supporting
- Monopoles
- Guyed towers
- Custom-designed radar towers
- Broadcast towers
- Power transmission
MEGATRO also designs and manufactures tower related products including:
- Fall protection
- Antenna brackets
- 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 railway steel structure , 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 railway steel structures are delivered to the galvanizing facility to be Hot DIP Galvanized.
Except otherwise specified elsewhere in the specification, the surface treatment and corrosion protection for all metal parts shall be in conformity with the latest revision of the standards listed below:
ASTM A 123 zinc (hot-dipped galvanized) coating on iron and steel products
DIN 55928 Protective painting of steel structure instructions
DIN 55945 Painting materials-Notions
DIN 18363 Paint work-Buildings
DIN 18364 Surface protection work for steel
DIN 53210 Determination of rust degree
DIN 55151 Determination of adhesion
ISO4628/3 Determination of rust penetration
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 Huckbolt 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.
Step bolt:
Each steel tower shall be provided with step bolts on one of the legs for single circuit steel tower and on two diagonally opposite legs for double circuit steel tower from approximately 2.5 meters above ground level to the cross arm and from thereon to each ground wire peak. Step bolts shall be furnished for each leg extension in an amount of 25% of the step bolt holes. These bolts shall not be less than 16 mm or 3/4" diameter, double nut type, 18 cm or 7" long with 35 mm or 1 5/8"diameter, symmetrical head, two hexagon nuts and spring washers, spaced not more than 45 cm or 18" apart. Each bolt shall withstand without permanent deformation a vertical load of at least 137 kg applied at the bolt head. If any technical specification, we will discuss with our client and confirm before mass production.
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.
Preparation for Shipping and Storage
To facilitate segregation of steel tower parts at the stockyard and to maximize the efficiency of erection, packaging of steel towers shall be as follows:
All steel tower parts, including stub angles, plates and steel tower parts member shall be color coded. The color code shall be painted on both ends of the steel tower parts for all angular members and around the edges for plates. The color codes shall be as specified in the Technical Data Sheets. All stub angles shall be packaged per unit steel tower per type i.e., four (4) pieces per bundle.
All cleats including bolts and nuts with spring washers for stub angles shall be packaged per unit steel tower per type in wooden boxes with corresponding color code painted on all corners of the box.
All basic body steel towers shall be packaged per unit steel tower per type. Each package shall not exceed three (3) metric tons. The contents of each package per unit steel tower per type shall be identical for any succeeding unit type. The numbering of each package shall indicate steel tower type (basic), steel tower number and number of pieces included in the package.
Example:
MG -Basic/Steel tower No./Package No./Qty. in this package
MG -Basic/ 1 of 200/ 2/ 8
All bolts and nuts with spring washers shall be package in tin cans or wooden boxes per unit steel tower per type and numbered as follows:
Example:
MG Bolts (Basic)/Steel tower No./Package No./Quantity
All plates and gussets for the basic steel tower shall be package in wooden boxes per unit steel tower per type and numbered as follows:
Example:
MG Plates (Basic)/Steel tower No./Package No./Quantity
All body extension steel tower parts shall be package per unit steel tower per type. The weight of each package shall not be more than three (3) metric tons. The contents of each package per unit per steel tower shall be identical for any succeeding unit steel tower. The numbering of each package shall indicate the steel tower type and extension steel tower number, and number of pieces included in the package.
Example:
MG Body Ext./Steel tower No./Package No./Quantity
MG Body Ext./Steel tower No./Package No./Quantity
All bolts and nuts with washers and plates for the body extensions shall be packaged in wooden boxes per unit steel tower per type and numbered as follows:
Example:
MG Plates & Bolts/Steel tower No./Package No./Quantity
All steel tower parts/members shall be marked as indicated in the steel tower parts list. The markings shall be embossed, the size of which will be approved by the our client.
All package numbers for the steel tower shall be in label form. The size of the label shall be 5 cm x 10 cm. The label shall be waterproof and all letterings on the label shall be printed. This label shall be attached on every bundle of package. Each bundle or package shall have at least two (2) labels, each label is visible on each side of the bundle.
All bundle or packages for steel tower shall be properly strapped to avoid disintegration of the bundle when subjected to unnecessary impact. The strap shall be properly placed so that the breakage of one (1) or two (2) straps will not allow disintegration of the bundle or package.
Smaller pieces shall be bundled, with all the pieces in any bundle having the same mark.
All small pieces such as bolts and connections for ground wire and insulators shall be packed in boxes of not over 70 kg gross weight each. Bolts of different size or length shall be wrapped in separate sacks before boxing. Description, quantity, bolt size, and length shall be clearly marked on the outside of the sacks and boxes.
When specified in the Purchase Order, bundling and packaging shall be in lots for each individual structure. Boxes or other containers shall be clearly marked to indicate the type of steel tower for which the enclosed material is intended, and the quantity and marks or description of contents shall be shown on the outside.
Shipping shall be as specified by the Purchase Order and shall be in complete steel tower lots. All identifications shown on bundles, boxes or other containers shall be included on Contractor's shipping and packaging lists.