How-To Guide
How to Trench for Fibre Optic Cable
A practical, step-by-step look at how fibre optic trenching is actually approached — from ground assessment through to reinstatement.
1. Assess the Ground Along the Route
Walk or survey the full route before committing to a machine. Fibre runs are often long and rarely uniform — a route might cross soft berm, compacted metal, and a section of sealed road or existing hard surface in the same day's work. Note where ground hardness changes, since that's what determines whether a standard chain will keep pace or a rock-capable wheel trencher is needed for sections of the run.
2. Confirm Depth and Width From the Network Design
Depth and width for fibre trenching are set by the network operator's or local authority's specification, not by the machine — confirm the required cover depth and conduit/duct count before trenching starts. See our depth and width guides for how these compare across the AFT range.
3. Match the Machine to the Carrier and Ground
Tractor-mounted chain trenchers suit long, open rural runs. Excavator-mounted units give more control on tighter civil or subdivision sites. A skid steer-mounted trencher is the practical choice for narrow, hard-surface urban trenching where full road closures aren't an option. For hard or rocky ground anywhere along the route, a rock-wheel-capable machine avoids slowing to a crawl partway through the job.
4. Cut, Then Lay Conduit Immediately Behind
A trencher with a conveyor system places spoil cleanly to one side, keeping the trench line clear for the crew laying conduit or duct directly behind the cutting head — this is where most of the real production-speed advantage over hand-digging or bucket work comes from on a long run.
5. Backfill and Reinstate
Narrower cuts mean less spoil to backfill and less surface to make good — on sealed roads and footpaths in particular, reinstatement standard and cost are directly tied to how clean and narrow the original cut was.
- Assess ground hardness along the full route before choosing a machine
- Confirm depth and duct/conduit width from the network design, not a default setting
- Match carrier (tractor, excavator, skid steer) to what's already available and the site access
- Use rock-wheel capability where hard or rocky ground is expected
- Keep the cut as narrow as the design allows to minimise reinstatement cost
Common Questions
How to Trench for Fibre Optic Cable: FAQ
How is fibre trenching depth and width determined?
By the network operator's or local authority's specification, not the machine — confirm the required cover depth and conduit/duct count before trenching starts. See our Trenching Depth Guide and Trenching Width Guide for how these compare across the AFT range.
What machine suits hard or rocky ground on a fibre run?
A rock-capable wheel trencher, such as the Wizz Wheel 75, keeps cutting through basalt-hard or rocky ground over distance where a standard chain would slow right down — a common requirement on long rural fibre runs through variable ground.
How do you keep reinstatement cost down on a fibre trenching job?
By cutting no wider than the design requires — a narrower original cut means less spoil to handle and less footpath, berm or sealed-road surface to make good afterwards.
Ready to Put a Trencher to Work?
Talk to the TrenchWorks team about your project, or request a quote for the right machine for the job.