Walking excavators, also known as spider excavators or spider diggers, are some of the most capable machines for excavation on the planet. Designed to climb, crawl, and stabilise themselves on terrain that would stop standard tracked diggers in their tracks, these machines are built for the jobs others turn down.
In New Zealand, where we have steep hillsides, narrow valleys, waterlogged ground, and regular slips, walking excavators are becoming a vital tool for safe, efficient earthworks. And with more extreme weather events each year, the need for true hard-access machinery has never been greater.
This guide breaks down what walking excavators are, how they work, where they can operate, and why they’re ideal for New Zealand conditions.
A spider excavator is a highly specialised excavator machine built with independent hydraulic legs instead of fixed tracks. These legs can extend, retract, and pivot individually, allowing the machine to “walk” over obstacles, climb steep slopes, and stabilise itself like a four-legged creature, hence the name spider excavator.
Unlike a standard excavator that needs a flat, stable surface, a walking excavator can set itself up on almost any terrain. It can raise or lower its chassis, anchor its legs into the ground, and even distribute its weight so lightly that it can work in boggy or soft environments without sinking.
The Menzi Muck, the world’s top walking excavator platform, is the machine used by Tough Terrain. It’s the global benchmark for stability, flexibility, and extreme-access capability. And we’re the only operator in New Zealand with this level of spider excavator technology.
These machines look unusual for a reason; every part is built for terrain that doesn’t play nice. Here’s how our spider excavators do what a standard excavator can’t:
The result is a machine that can walk into gullies, climb out of slips, stand on hillsides, and work in riverbeds, safely and efficiently.
Walking excavators are made for terrain that stops other machines in their tracks.
A spider excavator can climb slopes that would cause a tracked excavator to slide or overturn. It can anchor itself using its legs, allowing safe excavation on hillsides, slip zones, and unstable cut faces, a major advantage for New Zealand’s steep terrain.
Because the machine can “spread” its weight across multiple legs, its ground pressure is extremely low. This feature makes spider excavators ideal for:
Walking excavators outperform traditional excavators in shallow water. They can wade into streams or rivers up to ~2 metres deep, making them perfect for:
This water capability is one of the reasons Tough Terrain is heavily involved in waterway restoration and flood response work across the country.
Because a spider excavator can effectively walk into position, it eliminates the need for temporary access tracks, road cut-ins, or helicopter lifts. This design makes them ideal for:
If a standard digger can’t reach the site, a walking excavator probably can.
New Zealand’s terrain is rough, with steep hillsides, soft ground, narrow gullies and plenty of storm damage. Most of the places where work is actually needed are also the hardest places to reach.
Spider excavators are built for these conditions. They stabilise on steep slopes, climb angles that would flip a tracked excavator, and work safely in wet, unstable or waterlogged ground. Because they can walk, wade and anchor into the terrain, they handle slip clean-ups, storm response and precision digging without putting operators at risk. They also cut down costs. With a spider excavator, you don’t need access tracks, cranes, helicopters or multiple machines to get one job done. One machine gets in, does the work and gets out again.
Before contacting a contractor, homeowners or project managers should consider:
A reputable operator will guide you through these and provide a clear costed plan.
Spider excavators are rare globally, and in New Zealand, Tough Terrain is the only company with this level of Menzi Muck capability. We’ve built our entire business around extreme-access earthmoving, using spider technology every day on steep banks, slips, watercourses, and storm-damaged sites.
If your project involves steep, wet, or hard-to-reach terrain, a spider excavator is the safest, most efficient tool for the job, and Tough Terrain is New Zealand’s specialist. Get in touch with the team today.