An angle steel tower in the 90–120 m band is a different procurement problem from the 40 m towers most networks start with. The extra height turns four things that were details lower down into the main cost drivers: how the tower is split for transport, where the splices land, how many platform levels the antenna load needs, and whether the structure carries four legs instead of three. Get those four right at enquiry stage and the design package, the price and the delivery date all fall into place.
Six inputs decide most of the steel. The third column is what a buyer rarely sees until the drawing set arrives.
| What you decide | How it shows up at this height | What it changes downstream |
|---|---|---|
| 90, 100, 110 or 120 m | One additional body section and one working level per step, on a base that grows with height | Weight, base width, footing reactions and the number of pieces to erect all move together. The top 10 m is never the cheap 10 m |
| Wind and ice case | Design range 0–330 km/h; at 100 m the tower sees a far higher wind speed than the ground station next to it | Leg sections, bracing pattern, splice bolt counts. This is the input that most often separates a compliant tower from a cheap one |
| Antenna load and platform levels | Sector antennas, RRUs, dishes of 0.3–1.8 m, often across three or more levels | Platform framing, ladder and cable routing, local reinforcement. Dish clusters high on the tower add torsion, not just weight |
| Aviation marking | Red and white bands, obstruction lights at the levels your aviation authority requires | Paint or coated bands plus light brackets and cable runs, added at fabrication rather than on site |
| Transport | Sections split to fit 40 ft containers and to stay inside road limits | Where the splice joints sit, how many containers the order needs, and the heaviest piece the crane has to lift |
| Foundation | Four footings, sized from the leg reactions at the base of a much taller structure | Civil cost, land take, and the construction programme before the steel even arrives |
The base specification for the towers on this page: design to ANSI/TIA-222-G / F / H in MS TOWER, ASM TOWER, PLS TOWER or SAP2000; steel to Q235B, Q355B–Q420, ASTM A36/A572 Gr50-Gr65 or EN 10025 S235/S355; hot-dip galvanizing to ASTM A123 at ≥85 μm; Grade 8.8 bolts; welding to AWS D1.1; ISO 9001:2015 and CE certification; 25+ years service life.
Up to about 45–50 m, a three-leg frame is the cheaper answer almost every time: fewer members, three footings, smaller land take. Above 90 m the economics flip, and it is not because of weight alone.
The member-by-member comparison between the two layouts is covered in key differences between 3-legged and 4-legged angular steel towers; this page stays on what the height band changes.
Buyers often ask for a price "for a 90–120 m tower" as if one structure covered the range. It does not. This is what actually moves as you step up, and why we quote a specific height rather than a band.
| Height | Structure | Erection | What it costs you |
|---|---|---|---|
| 90 m | Shortest body, smallest base of the four, fewest sections | Mobile crane can often handle the top sections | Lowest steel weight and footing size in the band |
| 100 m | One more body section and level, base widens | Gin pole or crane with a longer boom; more lifts | Heavier bottom legs, larger footing reactions |
| 110 m | Heavier chord sections, more bracing per face | More splice joints, longer erection window | More containers, more crane days |
| 120 m | Widest base, largest members, marking and lighting at several levels | Climbing crane or gin pole sequence; aviation light cabling to the top | Highest steel and civil cost; the point where a full erection method statement is usually required |
The exact section count, member sizes and weight at each height come out of the design package for your wind and ice case — a catalogue table that claims one weight for "90–120 m" is describing a different tower from the one you will build. Ask for the drawing set at your specific height, and ask what the heaviest single piece weighs before you book a crane.
Going up the same structure: the taper is continuous, and the bracing changes with it — X panels low down where shear is highest, K panels higher up where the face is narrower.
On a 100 m 4 legged angle steel tower the antenna schedule decides the platform layout, and the platform layout decides how the tower is fabricated. Send it as a list: item, quantity, weight, projected wind area, mounting level and azimuth. Three sectors at the top plus a dish at the same level is a very different structure from three sectors at 80 m, three more at 95 m and two dishes at 110 m.
The platform itself is part of the quote, not an accessory: grating or checkered plate, handrail height, mounting frames sized to the antenna clamps, a cable ladder run from top to bottom, waveguide bridges where dishes are used, an aviation light bracket and a lightning rod at the top, plus fall-arrest anchor points for the climbing crew at every level. Items added after fabrication are the ones that get bolted on badly.
_1750666519_WNo_600d358.webp)
Towers in this height band are rarely re-quoted when these five items arrive together:
Add the marking requirement if the tower sits near an airport or on a flight path; adding bands and light brackets later means repainting a galvanized tower in the air. We reply within 24 hours with a configuration, an indicative weight and the questions that are still open.
A 120 m tower cannot be shipped as a 120 m tower. It is split into sections that fit a 40 ft container, and every split is a bolted splice that has to be designed, fabricated and inspected — which is why splice positions are set by the transport plan, not left to the site crew.
Each tower is trial-assembled at the plant before packing, with holes pre-punched on CNC lines to ±1 mm, so a splice that closes in Qingdao closes on site. Sections ship as strapped bundles with protected ends, marked to the packing list so the crew unloads in erection order. On site the work is bolted — Grade 8.8 bolts, no welding, no certified welder on the tower — and the plant runs at 2,000 t per month, up to 80 towers in a single month when a rollout needs them.
For towers at the top of this band, ask for the piece weights and the centre of gravity of each section at quotation stage. Those two numbers decide whether your crane, gin pole or climbing sequence can actually do the job, and they are much easier to design around than to discover on site.
Nobody repaints a 100 m tower cheaply, so the coating is the whole maintenance strategy. Standard is hot-dip galvanizing to ASTM A123 at a minimum 85 μm of zinc, measured on finished components, with fasteners to ISO 1461 or ASTM A153. That is what supports a stated service life of 25+ years.
| Site environment | What we change at this height |
|---|---|
| Desert, inland | Standard A123 coating; packing and touch-up matter more than microns, because handling damage on long members is the real risk |
| Coastal, salt spray | Coating taken to the heavy end of the A123 table for the steel thickness, drainage and vent holes confirmed before dipping, sealed splices |
| Industrial, chemical | Heavier zinc plus a duplex paint system over it where the specification calls for one |
| Required marking | Red and white bands applied at fabrication, before packing, so the tower does not arrive needing paint in the air |
Members and gusset plates leave the plant corner-protected and strapped by section, so the site crew unloads in erection order rather than re-sorting steel at the gate.
Zinc thickness is measured per batch and recorded, so the figure in the inspection file is a measurement rather than a claim. Below 85 μm on a coastal site, the maintenance-free window shortens quickly — that is the one place where saving on coating turns into a climbing crew every few years.
One order for the UAE covered 60 m, 80 m, 100 m and 120 m angle steel cell towers together — 22 containers, produced and shipped within 30 days, with packaging colour-coded by height so the site crew could tell the four tower sets apart on arrival. That is what a height ladder buys: one design family, one set of spares, four site requirements covered. The shipment record is here: 60m 80m 100m 120m angle steel cell tower shipment to UAE. A mixed 45–90 m order for the same market is recorded in 45m 60m 75m and 90m 60° angle steel tower shipment to UAE, and the shorter version of this family is covered on the 40–45 m three-leg telecom tower page.
_1750666425_WNo_1200d900.webp)
If you are buying an angle steel tower for a 90–120 m site, send the five items above and we will come back with a configuration at your exact height, a weight, the piece weights for erection planning and a price. If a three-leg, tubular or monopole solution suits your site better, that is what the reply will say.
