Est. 2005 · UK-wide trenchless installations07920 553 578·chris@swdd.co.uk
Trenchless Services
Guided, remote-controlled tunnelling for large, precise gravity sewers. We can arrange it. It is among the most expensive trenchless methods though, so for many crossings clients choose directional drilling instead once they see the cost.
Micro tunnelling drives a remote-controlled, laser-guided boring machine ahead of a rigid jacking pipe, installing large-diameter gravity sewers to a very tight line and level. Its closed face and slurry system let it work accurately in water-bearing and mixed ground that other methods struggle with, and we can arrange it where a job calls for it.
Where a large structural sewer has to hold tolerance below the water table, micro tunnelling earns its place and we'll say so. But it is among the most expensive trenchless methods, so for many smaller crossings, up to around 900mm, clients choose directional drilling instead once they see the cost. Here is the honest comparison.
Micro tunnelling at a glance
| Method | Remote, laser-guided MTBM |
|---|---|
| Typical diameter | ~250mm to 3000mm+ |
| Pipe material | Rigid jacking pipe |
| Best for | Large, precise gravity sewers |
| Ground | Handles water-bearing & mixed ground |
Typical figures for the method. We confirm what suits your crossing.
When each method wins
It matters for your budget too. Micro tunnelling shafts are expensive to sink and support, and with a directional bore you pay only for the smaller launch and reception pits instead, so the saving reaches you and not just us. In many cases we can also design the crossing so no man entry into the excavations is needed, which keeps it simpler and safer.
The right answer is whichever installs your pipe safely for the lowest cost and risk. Send us the drawing and levels and you'll get a straight answer, including a directional-drilling price to set against a micro-tunnelled crossing.
Head to head
| Feature | Micro tunnelling | Directional drilling |
|---|---|---|
| Launch | Launch + reception shafts | Small, shallow pits, no shafts |
| Guidance | Remote-controlled, laser-guided MTBM | Steered, survey-controlled bore |
| Product installed | Rigid jacking pipe (concrete/GRP/steel) | Flexible PE/steel pipe, ducts or casing |
| Typical diameter | ~250mm to 3000mm+ | Up to ~900mm |
| Ground & water | Handles water-bearing & mixed ground | Wide range; high water table needs care |
| Accuracy | Very high, to tight gravity tolerance | High; gravity to falls on suitable jobs |
| Relative cost | High, specialist plant & shafts | Lower where diameter & product allow |
Figures are typical ranges and depend on ground, diameter and site. We confirm them per job.
Questions answered
Micro tunnelling uses a remote-controlled, laser-guided micro tunnel boring machine (MTBM) to install a rigid jacking pipe to a very precise line and level. It is a steerable, guided form of pipe jacking with a closed face and a slurry or auger spoil system, which lets it work accurately in water-bearing and mixed ground, including below the water table. It is used mainly for large-diameter gravity sewers where tolerance is critical.
Both are guided trenchless methods, but they solve different problems. Micro tunnelling jacks a rigid structural pipe from shafts to a very tight gravity tolerance, and is built for large-diameter sewers and difficult, water-bearing ground. Directional drilling steers a curved path and pulls in a flexible pipe up to around 900mm. It is lighter, quicker and cheaper where the diameter and product allow, and it works from small, shallow pits rather than the deep shafts a tunnel needs.
Sometimes, chiefly at the smaller end of the range, up to around 900mm, where a flexible pipe or ducts are acceptable and the ground suits a steered bore. Where micro tunnelling is specified for a large structural sewer to tight tolerance below the water table, it is usually the right method. Send us the drawing, levels and ground information and we will tell you honestly whether your crossing can be drilled, and how the cost compares.
For large-diameter gravity sewers that must hold a tight line and level, long deep drives, and water-bearing or unstable ground that a steered bore cannot hold, micro tunnelling is the right tool, and we will say so plainly. The aim is the safest, lowest-cost installation, not drilling for its own sake.
Usually, where the crossing suits it. Micro tunnelling is among the most expensive trenchless methods. It needs specialist plant, a slurry or spoil system and launch and reception shafts. On crossings up to around 900mm where a flexible product pipe works, directional drilling is typically much cheaper and quicker. For large structural sewers in difficult ground, micro tunnelling earns its cost.
Related services
Steered crossings up to 900mm from small, shallow pits, with no shafts and a lower cost.
View service →The non-steered jacked method for big structural pipe, with an HDD cost comparison.
View service →Gravity drainage drilled to falls, often far cheaper than tunnelling.
View service →Send us the diameter, length, levels and ground conditions. We'll tell you honestly whether it needs micro tunnelling or can be directional drilled for less, then price it.