Megatro 400kv 4f1-Sjz Suspension Transmission Tower

• Usage: Crossing Tower, Tension Tower, Angle Tower, Terminal Tower, Transposition Tower, Branching Tower, According to Client′s Technical Specification
• Conductor Circuit: Single Circuit
• Certification: ISO
• Model NO.: MGP- 400Kv 4F1-SJZ
• Materials: Steel
• Standard: According to Client′s Technical Specification
• Style: According to Client′s Technical Specification
• Structure: According to Client′s Technical Specification
• We Can Design by Pls & Tower Software: According to Client Desing or Requirement
• Design Software: Pls
• Accessories 1: Power Fitting
• Accessories 2: Conductor and Cable
• Accessories 3: Tower Earthing Kits
• Transport Package: Export Standard Package
• Specification: AS PER CLIENTS
• Trademark: MEGATRO
• Origin: Shandong, China
• HS Code: 73082000
• Production Capacity: 3000sets/Year

Product Description

Megatro 400Kv 4F1-SJZ suspension transmission  tower


This photo refers to our 400Kv 4F1-SJZ suspension transmission  tower, it is widely used in our Chinese market. Some of technical features of this tower as follow:
1.tower steel
a)  Structural steel for all tower members, including all stubs and cleats embedded in concrete shall
conform to SABS 1431 Grade 300 WA or 350 WA, and shall be hot dip galvanised after fabrication.
b)  When tower designs utilising a mixture of Grade 300 WA and Grade 350 WA are offered by the
Contractor, all member sizes designated Grade 350 WA in any one tower design shall be strictly
Grade 350 WA.  It is the Contractor's responsibility to ensure that only one grade of steel is used
for any one-member size on any one tower.
c)  Certified mill test reports of the chemical and mechanical properties of the steel for the full quantity required for fabrication shall be obtained from the steel supplier.  Copies of these reports shall be retained at the Contractor's works for review.
d)  The means of marking and segregating Grade 300 WA and Grade 350 WA steel during receipt,
storage and fabrication, shall be supplied to the Project Manager for acceptance prior to the first
delivery of Grade 350WA steel.
e)Cut samples from deliveries of Grade 350 WA steel and conduct mechanical tests upon the samples to ensure that the steel is Grade 350 WA.  The frequency of testing shall
be subject to acceptance by the Project Manager.
f)  Only structural shapes included in the latest edition of the "South African Steel Construction
Handbook", published by the South African Institute of Steel Construction, shall be used.
Availability of shapes selected is the sole responsibility of the Contractor.
g)  To facilitate the transport of tower members, these shall be limited to a maximum length of 12,5m.
Here is the design strength of Chinese tower steel

Steel material		Anti-push, bending and press strength (N/mm^2)	Anti-shear strength (N/mm^2)
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

 
5 Here is the design strength of our Chinese tower bolts

Item	Grade	Anti-push strength (N/mm^2)	Anti-shear strength (N/mm^2)
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 400Kv Gate frame tangent transmission 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

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:

1. Telecoms
2. Power transmission
3. TV and Radio Broadcast
4. Roads and City Development
5. Wind energy solution
6. Steel structure and workshop

 
Our complete selection of towers includes:

1. Self-supporting
2. Monopoles
3. Guyed towers
4. Custom-designed radar towers
5. Broadcast towers
6. Power transmission

 
MEGATRO also designs and manufactures tower related products including:

1. Fall protection
2. Antenna brackets
3. 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 400Kv 4F1-SJZ suspension transmission  tower. 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 400Kv 4F1-SJZ suspension transmission  towers 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. All finished surfaces shall be level and free of tears, burrs, clots and impurities.
 
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
 
MEGATRO' 400Kv 4F1-SJZ suspension transmission  tower 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 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.
 
2. Bolts, nuts and washers
a)  Bolts and nuts shall be of mild steel Grade 4.6, and manufactured in accordance with SABS 136,and shall be hot dip galvanised.
b)  After galvanising, bolt holes shall be not less than 1,2mm larger in diameter than the
corresponding bolt diameter.
c)  Bolts of different diameters can be used on the same tower, provided that bolt sizes are not mixed in any one connection or plate.  The minimum size of bolt shall be 16mm.
d)  The threaded portions of all bolts shall project through the corresponding nuts by an amount not exceeding 15mm and not less than 3mm.
e)  No threaded portion of any bolt shall occur within the thickness of the parts bolted together. To
ensure this a single washer of suitable thickness shall be placed under the nut.
f)  The minimum thickness of washers shall be 3mm and the maximum thickness shall be 6mm.
g)  No lock nuts or spring washers shall be used on the tower.
h)  Where a pin-type connection is made at the top of masts on guyed structures, it shall be of a type secured by means of a bolt, nut and split pin.  The split pin shall be of stainless steel, with a
minimum diameter of 20% of the bolt diameter.
3.  Foundations for concrete or steel poles
a)  General
i) we can design of all foundations for pole structures.
ii)  The foundations shall be designed to withstand the maximum combinations of induced factored
moment, compression and torsion. The dead weight of the pole shall be included at unity factor of
safety.
b)  Testing
i)  Prior to the construction of any pole foundations, the Contractor shall, if instructed by the  Project Manager install in each general soil type encountered and at any additional locations, test poles for the purpose of carrying out full scale load tests to determine the moment carrying capacity in each soil type.
ii)  The test pole and foundation shall not be part of a final foundation.
iii)  The tests shall be conducted in the presence of the Supervisor.
iv)  The pole foundation shall be capable of withstanding the full design moment for 5 minutes with a displacement at ground level of less than 5mm.
v)  The test shall be continued to failure of either the pole or the foundation i.e. either a creep rate greater than or equal to 2mm per minute of the pole measured at ground level, or a pole tip
deflection greater than or equal to 10° with respect to the original point of intersection of the pole
with the ground.
vi)  Upon completion of the test, the pole shall be either removed or broken down to at least 600mm
below ground level and properly disposed of.
4. Tower code numbers and marking
a)  New tower designs accepted for manufacture will be allocated a tower code number consisting of three digits, This number is to be used in conjunction with the tower type letters and
tower descriptions given in the schedules to form the titles of the various towers.
· For example:
Suspension tower type 422 A
0° - 15 ° Angle strain tower type 422 B
These titles are to be used on all correspondence, drawings, test reports, etc., relating to a
particular tower.
b)  Each tower member shall be allocated an identifying number by the manufacturer, which shall
correspond, to the number on the appropriate tower erection drawing.
c)  The tower code number and the tower type letter are to be clearly stamped on every member of the tower as a prefix to the member mark number.  All steelwork shall carry a manufacturer's
identification marking consisting of a maximum of three letters.  This shall be of the same letter
height as the number code.  Acceptance of the marking shall be obtained prior to usage.  These
marks shall be stamped before galvanising and be clearly legible after galvanising and erection,
e.g.: on back to back members these markings shall be on the flange without stitches.
5.  Shackles and extension links
a)  Each tower with shackles and extension links for insulator string attachments of a size and strength suitable for attaching the conductor insulator assemblies, and earth conductor hardware assemblies to the tower at the appropriate positions.
b)  Shackles, split pins and extension links shall be designed and fabricated according to the relevant specifications.
c)  Shackles for insulator string attachments shall be of the correct length, to connect the insulator
hardware supplied to the attachment point on the tower.
d)  The shackles shall be of the type secured by means of a bolt, nut and split pin. The split pin shall be of stainless steel, with a minimum diameter of 5mm.
e)  The orientation shall be as follows:
·  Suspension shackle for earth and phase conductors:  When viewed on the transverse
face, the legs of the shackle are to be in the vertical plane and at right angles to the
direction of the line.
·  Strain shackle for earth and phase conductors:  When viewed on the transverse face,
the legs of the shackle are to be in the vertical plane parallel to the direction of the line.
7.1.8 Anti-climbing devices
a)  Anti-climbing devices shall be designed for each tower.  These are to be attached at a height of approximately 3m, but not less than 2,5m above ground level.
b)  Where long leg extensions are used, an anti-climbing device shall be installed on individual legs at a height of not less than 3m and not more than 5m above ground level.
c)  Anti-climbing devices shall be formed by stringing onto projecting steel supporting members,
fencing wire consisting of 2,5mm double-strand uni-directional twist pattern, galvanised steel
barbed wire.  Spacing between strands shall not be more than 100mm centres, the first being not
more than 100mm from the tower face, and forming an overhang of not less than 500mm beyond
the outer face of the tower.  This overhang distance shall be maintained at the tower corners.  On
small anti-climbing devices such as on legs of guyed "V" towers, twin single strand barbed wire
may be used.
d)  The strands of barbed wire shall be secured at intervals, not exceeding 2m, by spacers formed by pieces of the same barbed wire bound to the strung barbed wire by galvanised binding wire.
Where barbed wire other than galvanised steel is specified, the spacers and binding wire shall be
compatible.
e)  Where the design of the towers is such that they can be climbed on the inner face, a similar anti-
climbing device shall extend from the inner face of the tower.
6.  Step bolts
a)  One leg of each tower shall be equipped with step bolts at approximately 400mm centres, starting immediately above the anti-climbing devices and extending to the highest crossarm of the tower. The bolts shall be fixed to the main leg members of the tower by means of two hexagonal nuts. The length of the cylindrical section of each step bolt shall not be less than 150mm, as measured from the outside face of the main leg to the bolt head.  Holes for step bolts shall be on all leg extensions from ground level up.  No step bolts shall be installed below the anti-climbing device except for construction purposes.
b)  The bolts shall be uniformly spaced, continuous and in line over gusset plates.  Where 20mm
tower bolts are used 16mm step bolts may be fitted in a 21,5mm hole, but at connections only.  In
the connection this bolt shall be ignored when calculating the number of bolts required.
c)  In the case of double circuit towers, two diagonally opposite legs shall be equipped with step bolts and shall extend to the underside of the top crossarm.

Limiting L/r ratios
·  Leg members and main chord members in crossarm/bridge and earth conductor peak - 120.
·  All other members carrying calculated stress - 200.
·  Redundants not carrying calculated stress - 250.

·  The maximum allowable design stresses for bolts shall be as follows:
·  Shear on unthreaded portion of bolt  -  250mPa
On multiple bolt connections allowance must be made, in accordance with either
SABS 0162, ASCE Manual No. 52 or ECCS No. 39, for the group effect, which will
tend to decrease the permissible shear on the bolts.
·  Tension on net area of bolt - 400mPa.
7. Tension design
a)  "Tension-only systems" are not permitted.  Each member shall be designed for the forces it
attracts from the externally applied loads, due to its location and stiffness.
b)  If unequal angles are used, they should be connected by the long leg when practicable.  When
the outstanding leg exceeds the connected leg, the net area shall be determined as for an
equal angle based on the connected leg.
8. Bearing design
Bearing on contact area (bolt diameter ´ material thickness) ƒb = 575mPa.
9. Member thickness
a)  The outline or main chord members of a tower shall have a minimum thickness of 5mm
regardless of bolt size. The minimum thickness of steel sections using 16mm bolts shall be
3mm.  When using 20mm to 24mm bolts, the minimum thickness for any member shall be
4mm.
b)  Where members of the same size but of different thickness are to be used in the same tower design the difference in thickness shall be more than 1mm. Spacing of bolts
The distance from the centre of a bolt to the face of the outstanding flange of an angle or other
member shall be such as to permit the use of a socket spanner for tightening the nut.
Pad and plinth foundations for guyed tower centre supports
a)  The mast support foundations for guyed towers shall be designed to withstand, with less than 20mm
of settlement, the maximum foundation reactions resulting from the loadings stated in the Works
Information, with the dead weight of the tower included at unity factor of safety.
b)  The minimum depth of the mast support foundation/s shall be 750mm in type '1' and type '2' soil, and 1000mm in type '3' and type '4' soil.  The soil at the bottom of the foundation shall resist all stresses resulting from the vertical compressive loads and toe pressures due to horizontal shears.
The mass of the foundation less the mass of the soil displaced by the foundation, shall be included
in the vertical load applied.
c)  The foundations shall be designed for the maximum combinations of compression and horizontal shear forces.  In addition, a 900mm projection of the plinth above ground level in the case of cross rope suspension type towers, and a 650mm projection in the case of guyed 'V' type towers, shall be incorporated in the design to allow for leg extension increments.
d)  All concrete subjected to a tension where the permissible tensile stress is exceeded, shall be
adequately reinforced with steel reinforcing bars in compliance with SABS 920. The design shall be in accordance with the requirements of SABS 0100.
e)  Anchoring of the tower bases of guyed "V" towers shall be by means of anchor bolts. The maximum shear on anchor bolts shall be 0,65ƒy.  If the anchor bolts must resist compression loads from the base plate, the compression load shall be resisted by mechanical anchorage, and not by adhesion between steel and concrete, unless deformed bars are utilised for anchor bolts.
d)  Rock anchors
Foundations utilising grouted rock anchors will be considered by the Project Manager if the following
criteria are met:
i)  A minimum of four vertical rock anchors shall be used and connected to the structural steelwork
by means of a reinforced concrete pile/anchor cap.  Inclined rock anchors shall not be used
without the Project Manager's prior acceptance.
ii)  The rock anchors shall be designed to resist the full axial forces imparted by the maximum
combinations of uplift and compression loadings, and additional axial loads due to the total
horizontal base shear.  The design shall incorporate a 650mm minimum projection of the
foundation above ground level.  The rock anchors shall not carry any shear load.
iii)  The pile/anchor cap shall be designed to resist the total horizontal base shear. No horizontal
shear resistance shall be assumed for re-compacted excavated soil.  The base of the pile cap
shall be extended to a minimum of 150mm below the top of sound rock over its full area
irrespective of horizontal shear resistance requirements.
iv)  The rock anchors shall be reinforced for their entire length in order to resist the applied axial
forces and the reinforcing extends into the pile cap sufficiently and is suitably anchored to ensure full utilisation of reinforcement from pile/anchor cap to anchor.  The cap shall be
reinforced to withstand the shear and bending forces applied by the structural steelwork.  The
rock anchor reinforcing steel shall be debonded, by a method accepted by the Project Manager
for a length of 100mm above and 300mm below the pile cap base.
v)  Rock anchors shall only be installed in hard rock, or sound competent soft rock. Proposals to
utilise rock anchors in materials such as shale etc. must be specifically accepted by the
Project Manager after a pile/anchor test, as described in clause 6.1.6.4 e) below, has been
conducted.  An additional test to verify that the pile cap will resist the entire horizontal base
shear may also be required if so specified by the  Project Manager.  The lateral pressure on the
leading face of the cap in rock, as well as the friction on the two side faces in rock, shall be the
lesser of 135kPa or 80% of the permissible value determined from appropriate tests.
vi)  The use of grout mixes, including proprietary mixes, must be accepted by the  Project Manager prior to the use of such.  Documented evidence of use in other similar applications, which have been accepted by a recognised authority, shall be submitted as proof of suitability.  In-situ rock anchor testing shall be carried out as specified in clause 6.1.6.4 e) below.
vii)  Rock anchors with diameter smaller than 85mm shall only be installed in sound competent rock where the holes have uniform diameters, straight sides and special grouts is used (epoxy or
similar with 50mPa minimum strength) as approved by the Project Manager.  In-situ rock anchor
testing shall be carried out as specified in clause 6.1.6.4 e) below.