The standard single-pylon transmission tower. 4m OD base, 1m OD top, tapered concrete pylon held in compression by a single 20" L80 13Cr API 5CT tubular tensioned against a standard ATS caisson at foundation depth. Covers approximately 80% of every transmission tower in the deployment range as a stand-alone single pylon. The Phase 0 corridor's ±500kV HVDC backbone is built entirely on MMC-TB.
| Configuration | Single-leg, cross-arm topside |
| Legs per pylon | 1 |
| Base diameter | 4.0m OD (linear taper to 1.0m OD at top) |
| Wall thickness | 300mm at base, 100mm at top |
| Concrete grade | C65 precast (65 MPa characteristic strength) |
| Typical pylon height | 50–60m (standard 330kV through ±500kV); height varies by application |
| Foundation | 1 × 4m OD ATS caisson — drilled-and-grouted, depth per geology (typically 8–18m in NSW corridor) |
| Tubular | 1 × 20" × 171ppf L80 13Cr API 5CT — body yield 17.2 MN, joint yield 16.4 MN (premium connection) |
| Voltage range covered | 22kV distribution through ±500kV HVDC — approximately 80% of the network |
| Worked PT requirements | 22kV distribution: 1.0 MN · 132kV suspension: 4.2 MN · 132kV strain: 9.6 MN · 330kV AC suspension: 11.3 MN (69% utilisation) · 500kV AC suspension: 15.9 MN (at hard ceiling) · ±500kV HVDC bipole: 14.9 MN |
| Concrete mass per tower | ~210 tonnes (Megafactory cast-skin manufacture) |
| All-in cost per tower (volume) | ~$138,000 (vs ~$140,000 for steel lattice equivalent — cost-neutral at construction) |
| 60-year lifecycle NPV | ~$155,000 per tower (vs ~$295,000 steel lattice — 47% lifecycle saving) |
| Installation | 1–2 days per tower, 4–6 person crew, single crane day (vs 5–10 days, 8–15 crew, 3–5 crane days for steel lattice) |
MMC-TB — single-leg pylon render
SketchUp render / technical drawing — placeholder for production artwork. Replace with actual asset when available.MMC-TB is the single SKU that covers the bulk of continental transmission deployment. Same 4m base, same 20" L80 13Cr tubular, same ATS caisson — across distribution, sub-transmission, transmission, and HVDC bipole applications. Only the height, cross-arm configuration, and conductor attachment hardware vary per voltage class.
The cross-arms are captured between pylon segments and held in place by the tensioned tubular passing through them. They carry conductors for transmission applications (one cross-arm per circuit, three to four arms typical). The cross-arm hub geometry is patented (Patent 5) and allows mix-and-match arm fitment per project. The renewable tubular tension element (Patent 4) means the structural tubular can be inspected, retensioned, or replaced across the 80-year design life — extending operational life beyond what conventional embedded-rebar concrete can deliver.
MMC-TB is deployed across the entire SBC transmission network as the default single-pylon configuration. Phase 0 corridor's ±500kV HVDC backbone is entirely MMC-TB (suspension towers; MMC-TA at strain points). Phase 1, 2, and 3 continental corridors deploy MMC-TB across most suspension towers up to ±500kV HVDC.
MMC-TB is the workhorse of the SBC transmission deployment. Phase 0 corridor uses MMC-TB exclusively for the HVDC backbone suspension towers. International deployments will follow the same single-product approach.
The engineering of MMC-TB is documented in the MMC engineering memo series. The Models page is the catalogue — the Library is the engineering depth.
MMC-TB is the canonical single-pylon configuration covered by the Pole and Tower Architecture (Patent 6). The foundation system (Patents 1, 2, 3 — Foundation Core, Integrated Foundation, Foundation Drilling System), the Architectural Framework (Patent 4 — modular precast segments, renewable tension element), and the Manufacturing Architecture (Patent 7 — cast skin / rib / die assembly-line manufacture) all apply to MMC-TB. The conductor cross-arm capture geometry is covered by Patent 5.