SYSTEM 02.02 · TUNNEL CONFIGURATION
TN-850: 8.5 m single-span tunnel, 4.0 m ridge height.
Reference tunnel for larger tunnels with machinery access. Span 8.5 m, ridge 4.0 m, arches at 2.0–2.5 m. More volume per arch, same construction detail.
Multi-span film house, exteriorProject photo
At 8.5 m span the arch is the whole structure — there is no gutter to share the load. That makes the arch section, the arch spacing and the anchor the three things to get right. TN-850 is priced per arch and per metre of run, which makes it easy to compare against a competitor who prices per m².
| Member | Section | Spacing | Note |
|---|---|---|---|
| Arch | Ø60.3×1.8–2.0 or oval 30×60–30×70 | 2.0–2.5 m | bent to radius |
| Longitudinal brace | Ø33.5×2.0 | 1.0–1.5 m | ties arches together |
| Base rail (optional) | Ø33.5×2.0 | per side | film fixing line |
| Anchor | ground screw 600–800 mm | each arch leg | or concrete-in |
| End frame | Ø48.3×2.0 | each end | door frame |
| Film fixing | W-clips / springs | per arch | or channel profile |
Reference only. Wind exposure decides anchor type and arch spacing.
TN-850 — dimensionsXY-TN-850
- Span
- 8.5 m
- Ridge height
- 4.0 m
- Arch spacing
- 2.0–2.5 m
- Bay (run length)
- per project
- Arch
- Ø60.3 / oval 30×60
- Anchors
- ground screw or concrete
- Cover
- film to ground or rail
- Frame weight
- see quotation
- Arches per 100 m run
- 40–50
- Covered per arch
- ≈ 17.0 m²
- Loading
- 40HQ
- Design by
- Your engineer
Indicative values — the quotation and mill certificate carry the final figures.Rev. 2026-11
Where tunnels go wrong
- Arch spacing stretched to save steel, with no re-check on wind.
- Anchors bought last, then improvised on site.
- Film fixed with clips instead of a channel, then ballooning in the first storm.
- No longitudinal brace, so the run racks sideways.
Related
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- 08.04Wind loadGreenhouse wind load: pressure and uplift, exposure, bracing, anchors and the open-side ca→
- 04.06.03Anchors & base platesAnchors & base plates for greenhouse frames — ground screws, concrete-in anchors, base pla→
PRICE THIS TUNNEL
Quote TN-850 per arch and per run
Send the run length, number of runs and the wind figure. We price arches, braces, anchors and clips as separate lines.