Suspension, tension, deadend and transposition towers, fabricated to IS 802 and hot-dip galvanized on our own kettle. The type is decided by where the tower sits in the line, not by what is in stock.
A transmission line is not one tower repeated. It is a sequence of tower types, each doing a different job, and the proportion of each is what actually drives the tonnage on a line contract. Indo East fabricates all four principal types from IS 2062 steel, to the tower designer’s drawings under IS 802, galvanized to IS 4759 at 85+ microns.
What we do and do not do: we are a fabricator and galvanizer. Tower design — the structural analysis, the loading tree, the member schedule — comes from your designer or the utility’s approved tower type. We build it, prove it and coat it.
| Type | Where it goes | What it carries |
|---|---|---|
| Suspension | Straight runs and very small deviation angles — the majority of towers on most lines | Vertical conductor weight and wind. The conductor hangs from an I-string; longitudinal load is small in normal operation |
| Tension (angle) | Where the line changes direction | The resultant of conductor tension either side of the angle, which grows with the deviation. Heavier than suspension for the same line |
| Deadend (terminal) | Line ends, substation entries, and as anti-cascade points along a long line | Full conductor tension from one side only. The heaviest type, and the one whose foundation costs most |
| Transposition | At intervals along a long line | The same loads as its base type, but with the phase positions rotated to balance impedance across the three phases |
The mix matters commercially: a line across flat farmland is mostly suspension towers; the same circuit length through hills, river crossings and road crossings carries far more tension and deadend towers, and weighs considerably more. A tonnage figure without a type breakdown is not a quotable scope.
| Parameter | What we work to |
|---|---|
| Voltage classes | 33 kV, 66 kV, 110 kV, 220 kV, 400 kV, 765 kV |
| Tower types | Suspension, tension, deadend, transposition |
| Design reference | IS 802 — Part 1 is the designer’s document, Part 2 the fabricator’s. Ours is Part 2 |
| Wind loading | IS 875 Part 3: Vz = Vb × k1 × k2 × k3 × k4. The basic wind speed is a property of your site, not ours |
| Steel | IS 2062 Grade A, B and C; IS 8500 where specified. Angles, plates and, where the design calls for it, tubular sections |
| Galvanizing | IS 2629 process, IS 4759 coating mass — 85+ microns, recorded per batch |
| Fasteners | IS 1367 property classes 4.6, 5.6 and 8.8 as the drawing specifies |
| Proving | Prototype and pre-assembly before bulk fabrication; jigs made in our own tool room so the hole pattern repeats across thousands of members |
The two digits of a fastener class are arithmetic, not a part number — 8.8 means 800 MPa tensile and 80% of that as yield. See IS 1367.
A transmission tower is thousands of members that must bolt together on a hillside, in sequence, without a drill. The failure mode is never one bad member — it is a hole pattern that is three millimetres out, repeated four hundred times. Prototype assembly at the works, before bulk fabrication is released, is what catches that.
It is also the stage at which a third-party inspector adds the most value, which is why we propose it as a hold point rather than waiting to be asked.
Answered from our own line, not from the standard's cover page.
No. We are a fabricator and galvanizer. The structural design, loading tree and member schedule come from your designer or from the utility's approved tower type. IS 802 Part 1 is the designer's document; Part 2 is the fabricator's, and Part 2 is ours.
A suspension tower sits on a straight run and mainly carries the vertical weight of the conductor and wind on it. A tension tower sits where the line changes direction and carries the resultant of the conductor tensions on either side of that angle, so it is heavier for the same line. A deadend tower takes full conductor tension from one side only and is heavier still.
IS 802 for the tower itself, IS 875 Part 3 for wind loading, IS 2062 for the steel, IS 2629 and IS 4759 for galvanizing, and IS 1367 for fasteners. Where an export specification calls for ASTM A123 or EN ISO 1461 galvanizing instead, we work to that and say at quotation where the requirements differ.
Yes, at the works before bulk fabrication is released. A tower is thousands of members that must bolt together on site without a drill, and the failure mode is a hole pattern a few millimetres out repeated hundreds of times. Prototype assembly is where that is caught, and we propose it as an inspection hold point rather than waiting to be asked.
Some items we manufacture and some we buy in and galvanize to the same standard. We mark which is which against your bill of materials before you order.
Annual capacity is over 18,000 MT across fabrication and galvanizing, with a maximum single-piece fabricated weight of 5 tonnes. Tower work sequences through a 7.0 m kettle, so member length matters as much as tonnage to the schedule.
Tell us the standard, the coating requirement and the component, and we will confirm in writing what we can hold and how we will certify it. Galvanizing is on our own floor, so the answer comes from us and not from a sub-contractor.
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