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Heavy duty digging bar and chain with replaceable sprocket tip
High-performance easy start professional engine
Puncture-proof quick removal wheels


The TerraTrencher™ provides quick, easy, versatile trench digging when and where you need it.

Able to be used either freehand or with a Wheel Support accessory, it digs rapidly with little turf or ground disturbance. This allows rapid back-filling and quick site cleanup, increasing your productivity and profit on every job.


We invented portable trenching!


TerraTrencher 500

TerraTrencher 800


Highly Recommended
I was told about the TerraTrencher by one of my electrical contractors. He was using his to cut 600 mm deep trenches to bury electrical cables.
I saw him operating on one of my building projects and was highly impressed. The speed firstly, and the fact that he was cutting such a tiny slot. In the past this would have been done with a digger, 300 mm wide, then back filled.
For some years I have been trying to solve a ground water problem that I have in a very large lawn and was recommended to use a product called Mega Flow Drainage.
This is a very rigid plastic reinforced drain. It goes into a narrow 300mm deep trench, on edge, so it was obvious I needed a TerraTrencher.
Well, we got 500 meters trenched in no time at all.
I can highly recommend the TerraTrencher to anybody doing this sort of work.

Kip KempthorneSt Heliers

Magnificent little machines!
We are so grateful for the two machines we purchased from you five years ago, they are incredible.
As you know we install a tremendous amount of irrigation pipework. The Terratrenchers are so efficient and do such a nice neat job I don’t know what I’d do without them, and your backup service is fantastic. It’s always a pleasure working with you, congratulations on inventing such a magnificent little machine!

Wayne GilinskyWaiheke Island

About Us


The TerraTrencher, originally called a Terrasaw, was invented and developed in Northland, New Zealand by Keith Fergusson. As the world’s first portable powered mini trencher it created a whole new category of digging tool, with unique capabilities. After years of development to meet the extreme demands of commercial trenching, it has become the niche “go-to” tool for an ever-growing range of professional and private users.

TerraTrencher products are manufactured and supplied by Terrasaw Industries Ltd, with our headquarters in East Tamaki, Auckland, NZ.

We are proudly New Zealand owned and operated and have a network of participating Stihl shop dealers throughout Australasia and in several other regions.

TerraTrencher Australia’s Head Office is located in Brisbane and has dealers in all the major centres.


Where are you located?

TerraTrencher products are manufactured and supplied by Terrasaw Industries Ltd. Both Terrasaw Industries Ltd and TerraTrencher Global Ltd (our international arm) are New Zealand owned and operated and located in East Tamaki, Auckland, New Zealand.

TerraTrencher Australia’s Head Office is located in Brisbane and has dealers in all the major centres. We have a network of participating Stihl shop dealers throughout Australasia and in several other regions.

Can I hire a TerraTrencher?

Yes, customers in the greater Auckland area can hire a machine direct from us (booking is required).

How deep and wide does it trench?

The TT500 model can cut a neat trench up to 500mm (20 inches) deep by 38-40mm (1 ½ inches) wide and the TT800 model can cut a trench at least 670mm (26 inches) deep by 38-40mm wide.

Can I buy parts to convert my existing chainsaw?

All fitted TerraTrencher models are dedicated trenchers, built for professional trenching. Typically each model is sold as a complete unit with a power head specifically matched to the trencher for its torque, power and its superior air filtration system, which we further enhance with our custom filter kits.

However, if a customer already has (or intends to purchase locally) a compatible Stihl power head from the MS 4, 5 or 6 professional series it is possible to directly supply a conversion kit with detailed instructions. Contact us to confirm suitability.

What are customers using this trencher for?


  • fibre cable
  • data & telecoms cable
  • household mains electrical cable
  • low-voltage water feature and garden lighting cable
  • gate control cable
  • dog perimeter fence cable
  • robotic mower control cable
  • farm under-gate electric fence cable.
  • household water pressure lines
  • gas lines
  • farm water reticulation lines
  • trough connection lines
  • irrigation feeder and drip lines
  • sewerage soaker lines
  • sewer and household rainwater pipe


  • septic/water treatment tank installation
  • undercutting and transplanting shrubs and trees, especially fibrous root varieties like palms.
  • horticultural root pruning in tight spaces
  • installation of root barriers
  • cutting footings and foundations
  • cutting slit/French surface drains
  • garden edging
  • commercial fencing
  • predator-proof fencing
  • land slip remediation

even ice fishing!

How does the price compare to other trenching machines?

A TerraTrencher costs much less than conventional diggers but it is hard to compare, being a uniquely portable trenching unit. There is no other trencher available that can perform as well as a TerraTrencher. This patented unit is an engineered design and built to be a professional contractors “Trencher of Choice.” Beware of cheap unsafe copies! If you look at either the capital or hire costs of conventional trenching, including the additional cost of trailers, special transporters, much larger cost of turf re-instatement and the total labour time involved, a TerraTrencher will typically save you significant money.

Can I trench through tree roots?

Yes! The self-sharpening digging teeth enable cutting through tree roots up to 30mm (1 inch) in diameter. In fact some contractors use our equipment for root pruning, root barrier installation, and to undercut and transplant trees.

How long does a digging chain last?

That really depends on the type of soil. In good loamy or organic soils you can expect to trench for anywhere between 800-1000 metres (3,300 feet) or more per chain. If you are trenching in hard clay, sandstone or rocky conditions you can expect somewhat less distance.

What happens if it hits a rock?

Even in friable soils it is common to unexpectedly strike a rock or other solid object. If the rock is approximately the size of the trench the TerraTrencher teeth will wrench it free and remove it. If the rock/solid object is solidly in place the operator feels the obstruction, rises over it and continues trenching. The obstruction is later removed with a pick, crowbar or similar.

Does the trencher have safety features?

Yes, the TerraTrencher has multiple primary and secondary safety features. These include good ergonomics/weight distribution, an ideally geared/manageable digging chain speed, a durable dirt guard that can handle rocks and a strong drive chain guard. It also has replaceable shear bolts to protect the equipment in the event of an immovable object strike and electrical isolation on the wheel support control handle. The Owner’s manual has full safety instructions which are summarised on the side panel of the chain guard. Importantly, it also retains the safety features designed into one of world’s best chainsaw powerheads, including a chain brake for kick-back protection, anti-vibration engine mountings and a chain catcher.

Can I trench across a gravel farm raceway?

Yes, in fact undergrounding water pipes or electric fence cable across a race or a gateway is perfectly suited to a TerraTrencher used freehand. It’s one of the reasons that the trencher was invented. If the rock/gravel is compacted, use a pointed crowbar dropped every 50mm (2 inches) to loosen the surface. This makes trenching easier and extends the life of your chain. Remember, the TerraTrencher is primarily designed to dig soil, not compacted rocks or stones. If you routinely trench in abrasive pumice or rocky soils, you might benefit from our hard faced chains. See “Useful Info/Chain Guide”, and “Spare Parts/Digging Chains”.

Is the TerraTrencher able to do wider trenches?

Yes, you can lay wide pipe (e.g. for sewer or rainwater lines) by doing 2 parallel cuts at appropriate width and removing the centre. This technique can also be used to quickly carve out building footings/foundations.

What about cutting tight bends?

Yes, you can trench around a 200 litre (44 gallon) drum! You can even cut 90° junctions to suit irrigation “Tees” etc. Try doing that with any other trencher!

The easy ability to cut tight or gentle curves can often reduce the need for pipe elbows or joiners, reducing cost and installation time.

What is the advantage of the wheel support kit?

The wheel support has several advantages when cutting longer trenches. It supports the weight of the unit, reducing user fatigue – the remote throttle control allows easy operation from a standing position. The wide back strap allows the operator to use their body weight to keep the trencher moving at optimum speed with minimal effort. For those needing deep trenches it permits steep digging angles to fully vertical, and has a rotary depth adjuster for easy maintenance of a constant depth. With its quick-release handle you can go back to versatile freehand digging in seconds.

Does this trencher have any environmental benefits?

Yes, several. It uses much smaller engines than conventional trenchers and requires no trailer or special/heavy vehicle to transport it. As a result, fossil fuel emissions are significantly reduced.

Because it cuts such a slim trench the ground/soil structure disturbance is kept to a minimum. Not only is this very pleasing to property owners, it reduces topsoil erosion, vegetation loss and the impact on soil fauna and flora. With so little turf disturbance, re-instatement – even of manicured lawns – is rapid. (See “Videos”).

This product is almost completely recyclable. At our head office we are happy to receive TerraTrencher material for recycling or disposal.

Are there special techniques for using this kind of equipment?

Yes, being the inventor of this category of digging tool we also developed a comprehensive 20 page manual that include lots of tips to help you to be a highly efficient and profitable operator.

Where can I get training?

Individual and group or corporate training is available by arrangement.