The standard single-pylon transmission tower covering approximately 80% of MMC transmission deployments — 132 kV through ±500 kV HVDC suspension. The Phase 0 corridor backbone runs on MMC-TB. Single 4 m base, single 20″ L80 13Cr tubular, standard ATS caisson.
Per-tower cost is split into three layers: Structure (foundation, pylon, tubular, cross-arm), Services (tower-mounted equipment for the transmission service), and Install (all field labour and plant). Total per tower is the sum of the three; per-km figures shown at 100 m typical transmission spacing (10 towers per kilometre). Actual deployment density varies with voltage and terrain.
Foundation, pylon column, tubular tension element, cross-arm. Module costs are Megafactory pour rate + Hub and die allocation at moderate platform utilisation (~$310/module). Pre-feasibility grade, ±30%.
| Item | Per tower (AUD) | Per-km (AUD) |
|---|---|---|
| Cutter head (sacrificial hybrid) | $10,000 | $100,000 |
| Caisson ring segments (precast concrete) — 4 m OD, 300 mm wall, C65, 15 rings at 15 m depth | $10,275 | $102,750 |
| Caisson anchor cap (precast concrete) | $935 | $9,350 |
| Pile cap / base slab (precast concrete) | $935 | $9,350 |
| Pressure grout — annular grouting, rock socket bond | $800 | $8,000 |
| Tubular tension element — 20″ × 171 ppf L80 13Cr API 5CT, ~17 m | $12,240 | $122,400 |
| Column segments L1–L6 (precast concrete, 6 tapered) | $4,560 | $45,600 |
| Cross-arm (P#7 precast + steel rib, conductor attachment hardware integrated) | $1,950 | $19,500 |
| Structure subtotal | $41,695 | $416,950 |
Tower-mounted equipment for the transmission service. The conductors themselves are catalogued on the HVDC Transmission service page and added to deployment cost.
| Item | Per tower (AUD) | Per-km (AUD) |
|---|---|---|
| Conductor attachment hardware (insulator string sets) | $3,500 | $35,000 |
| Fibre optic OPGW attachment fittings | $600 | $6,000 |
| Aviation lights + earthing + bonding | $1,200 | $12,000 |
| Anti-climb, signage, access | $800 | $8,000 |
| Services subtotal | $6,100 | $61,000 |
All field labour and plant required to deploy the tower and string the conductors. Drilling rig service charged at ~$1,200/hour all-in. Includes site access, survey, easement and permits, and project management allocation per tower.
| Item | Per tower (AUD) | Per-km (AUD) |
|---|---|---|
| Foundation drilling (8 hrs × $1,200/hr, 15 m baseline) | $9,600 | $96,000 |
| Pylon segment erection (6 segs + tubular + tensioning) | $4,500 | $45,000 |
| Cross-arm placement | $1,500 | $15,000 |
| Conductor stringing (allocated per tower) | $8,000 | $80,000 |
| Earthing, OPGW, lighting install | $2,000 | $20,000 |
| Site access + survey (per tower allocation) | $3,000 | $30,000 |
| Easement + permits (per tower allocation) | $2,500 | $25,000 |
| Project management + supervision | $4,000 | $40,000 |
| QA, commissioning, energisation | $1,500 | $15,000 |
| Install subtotal | $36,600 | $366,000 |
Structure + Services + Install. Conductor cable itself catalogued separately on the HVDC Transmission service page; deployment cost = tower cost + conductor per-km. At 100 m typical transmission spacing this works out to 10 towers per kilometre.
Pre-feasibility grade, ±30%. Modules costed at Megafactory pour rates from Memo 2 (Megafactory Economics) plus moderate-utilisation Hub and die allocation (~$310/module). Install rates are pre-feasibility benchmarks against light civil construction at corridor scale. All figures AUD.
The MMC-T tension sizing memo and the MMC-TB model page state ~$138,000 per tower as the market-comparable cost (vs ~$140,000 for steel lattice equivalent). The bottoms-up build cost on this page comes in lower because it reflects the build-stage cost only. The difference represents project margin, contractor overhead, financing, and contingency applied between the build cost and the delivered price.