Est. 2005 · UK-wide trenchless installations07920 553 578·chris@swdd.co.uk
Design, Survey & Support
Confirm what we're drilling through before we start. Trial pits, boreholes and the right testing prove the ground, so the bore, the tooling and the price are built on fact rather than assumption.
The ground is the single biggest variable in any crossing. It decides the method, the tooling, how the bore behaves and, in the end, the price. The surprises that hurt, a band of cobbles, a slab of rock, high groundwater, are the ones found halfway across rather than up front.
So we prove the ground before we drill. Where the ground is soft enough to work cleanly we dig trial pits ourselves, a quick and fair alternative to a borehole on a shallower crossing, though we leave breaking out tarmac and concrete to others. For deeper boreholes and laboratory testing we bring in specialist ground-investigation firms, specify the tests that matter for drilling and interpret the findings for the bore. On larger jobs this is the work the ground report is built from, the report the contract is then priced and risk-shared against.
The testing we ask for is the testing that changes the drill. Unconfined compressive strength (UCS) sizes the tooling for rock, standard penetration tests (SPTs) gauge how dense or stiff the soils are, particle-size grading flags the cobbles and gravels that catch people out, and the plasticity of clays tells us how they will react with the drilling fluid. We concentrate on the geotechnical results that bear on the bore, not chemical or contamination testing.
What you get
| Trial pits | Dug in-house in soft, workable ground (we leave tarmac & concrete break-out to others) |
|---|---|
| Boreholes | Arranged with specialist GI firms, specified & interpreted for the drill |
| Testing | UCS rock strength, SPTs & the geotechnical tests relevant to the bore |
| What we look for | Soil & rock type, strength, cobbles, groundwater |
| Feeds | Bore design, tooling choice & the price |
| Why | Fewer surprises mid-bore, where they cost the most |
Boreholes and lab testing arranged with specialist firms, then interpreted for the drill.
Questions answered
Because the ground decides almost everything. The method, the tooling, how the bore behaves and what it costs all come down to what we are drilling through. A bore that is straightforward in clay is a different job in rock, and a surprise like a band of cobbles or buried obstructions partway through is far cheaper to plan for than to hit blind. Knowing the geology and groundwater along the line lets us design and price the crossing properly.
Partly. Where the ground is soft enough to work cleanly we dig trial pits ourselves, often a quick and fair alternative to a borehole on a shallower crossing, though we leave breaking out tarmac and concrete to others. For deeper boreholes and laboratory testing we bring in specialist ground-investigation firms, specify the tests that actually matter for drilling and interpret the results for the bore. Either way you get a clear picture of what we are drilling through before we mobilise.
The tests that change how the bore behaves. Unconfined compressive strength (UCS) tells us how hard the rock is and what tooling it needs, standard penetration tests (SPTs) gauge how dense or stiff the soils are, particle-size grading flags the cobbles and gravels that catch people out, and the plasticity of clays tells us how they will react with the drilling fluid. We focus on the geotechnical side that affects drilling rather than chemical or contamination testing, which is not our field.
Often one does, especially on bigger schemes, and we will work from it. Send us the borehole logs and any report and we will interpret them for the crossing, tell you what they mean for the method and the tooling, and flag anything that still needs proving before we drill. There is no need to investigate the same ground twice.
Yes. We have drilled through very strong rock, including basalt, using our All Terrain and air-hammer methods. But we want to know the rock is there first. Confirming the strength and extent of rock up front is exactly what ground investigation is for, so we bring the right tooling and price the job on reality rather than on a guess.
Related services
The early appraisal that ground investigation turns from estimate into fact.
View service →When the investigation confirms rock, the method built for it.
View service →Finding the buried services, the other half of knowing the ground.
View service →Tell us the line of the crossing and we'll confirm what's under it, then design and price the bore on the real ground.