Bus posts, gantries, equipment support structures, deadend structures and lightning masts — fabricated and hot-dip galvanized on one floor at Howrah, to the utility specification that applies at your substation rather than a generic one.
Indo East fabricates and galvanizes substation steelwork from 33 kV to 765 kV. The structures are designed to the purchase specification of the utility buying them, fabricated from IS 2062 steel and hot-dip galvanized on our own kettle to IS 2629 and IS 4759 — 85+ microns, read on a calibrated gauge and reported per batch.
We are an approved vendor to WBSEDCL, WBSETCL, OPTCL, BSPTCL, NBPDCL and SBPDCL among other state electricity boards, and engineering companies including L&T, ABB, Siemens, Alstom T&D and Polycab. Each of those approvals began with a procurement team inspecting this works.
The structure types a switchyard actually needs, and what each one carries.
| Structure | What it does | What decides the design |
|---|---|---|
| Bus post structures | Support the busbar and its post insulators at the required phase-to-earth and phase-to-phase clearances | Voltage class and the clearances in the utility specification; short-circuit forces on the bus |
| Gantry structures | Carry the incoming and outgoing line conductors into and out of the switchyard, and take the conductor pull | Span, conductor tension and wind loading to IS 875 Part 3 — Howrah sits in the 50 m/s basic wind zone, yours may not |
| Equipment support structures | Support circuit breakers, isolators, current and potential transformers, surge arresters | The equipment maker’s mounting drawing, which is why we ask for it rather than assuming |
| Deadend structures | Terminate the line at the substation and take the full conductor tension | Conductor type, tension and the angle of approach |
| Lightning masts | Carry the shielding air terminal above the switchyard | Protected zone required, and the mast height that follows from it |
| Distribution structures and feeder pillars | Rail poles, feeder pillars and distribution steelwork below transmission voltages | Utility standard drawing |
A lightning mast is not a high mast: one shields a switchyard from a strike, the other carries floodlights. They are confused constantly in enquiries — see the comparison page.
| Parameter | What we work to |
|---|---|
| Voltage classes | 33 kV, 66 kV, 110 kV, 220 kV, 400 kV, 765 kV |
| Structure types | Bus post, gantry, equipment support, deadend, lightning mast, feeder pillar |
| Steel | IS 2062 Grade A, B and C; IS 8500 where a higher-strength micro-alloyed grade is specified; IS 1239 pipes |
| Design references | IS 802 for lattice structures, IS 875 Part 3 for wind loading, CEA regulations, IEC and the customer specification |
| Galvanizing | IS 2629 process, IS 4759 coating mass — 85+ microns, DFT readings recorded per batch |
| Connections | Bolted, with fasteners to IS 1367 property classes 4.6, 5.6 or 8.8 as specified |
| Inspection | Third-party inspection by SGS, Bureau Veritas, TÜV, DNV, Intertek or a utility-nominated agency, at stages agreed before production |
Where a utility specification calls for 610 g/m² rather than a micron figure, that is the same requirement expressed the other way — see IS 4759 for the conversion we work to.
Answered from our own line, not from the standard's cover page.
WBSEDCL, WBSETCL, OPTCL, BSPTCL, NBPDCL and SBPDCL among other state electricity boards, alongside engineering companies including L&T, ABB, Siemens, Alstom T&D and Polycab. We hold 39+ active vendor approvals in total.
33 kV, 66 kV, 110 kV, 220 kV, 400 kV and 765 kV. The voltage class sets the clearances, which sets the structure geometry; the utility specification governs.
IS 2629 process and IS 4759 coating mass at 85+ microns, read on a calibrated DFT gauge and recorded per batch. Galvanizing is on our own kettle at Howrah, not sub-contracted, which is why we can commit to the figure in writing.
Yes, and we prefer to. Send the utility specification and the standard drawing set. Where a tender requires design rather than fabrication to drawing, we work from your consultant's drawings.
Some items we manufacture and some we buy in and galvanize to the same standard. Against your specific bill of materials we mark which is which before you order, rather than letting you assume every line comes off our own floor.
7.0 metres. Our kettle is 7.0 m long by 1.2 m wide and 1.6 m deep, at about 450 degrees Celsius. Longer members are double-dipped, which is standard practice but leaves a visible overlap line — we raise that before quoting.
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.
Request a quotation Galvanizing job work