Supporting Tunneling Projects? Here’s What You Need to Know About Shaft Sinking Through Rock Without Blasting

When it comes to tunneling projects—whether you’re installing a subway line under a city or running water mains across town—the main action often gets the spotlight. But before the tunnel boring machine even gets started, there’s a big job to do: shaft sinking.

And if that shaft hits hard rock, you’ve got a challenge on your hands.

At Rock Busters, we support tunneling projects and rock breaking contractors of all kinds across North America with non-blasting rock breaking solutions that keep your timeline moving, your budget intact, and your team safe.

Here’s how we help get your project through the the rough patches (literally).

TBMs, MTBMs & Shaft Sinking for Rock Breaking

There are a few different ways tunnels are built, depending on the size, location, and purpose:

Drill & Blast: A traditional method used in rural or mountain tunnels where blasting is permitted.

TBMs (Tunnel Boring Machines): Massive, house-sized machines that bore subway lines or tunnels under cities and rivers. These only move in straight lines—so they always require entry and exit shafts, plus additional access points called adits.

MTBMs (Micro Tunnel Boring Machines): Smaller machines (up to about 4 ft in diameter) used for water mains, utility tunnels, and storm sewer lines. Like TBMs, they also require shaft sinking.

Before boring begins, you have to dig the vertical entry and exit shafts. That’s where things get tricky—especially when you’re dealing with solid rock and tight urban environments where blasting is off the table.

What Are the Real Costs of Tunneling?

You know we’ve been there and done it, so we’ll help put it into perspective:

• Using an MTBM to bore a 4-foot-diameter tunnel costs about $3,000–$3,500 USD per foot.
• By comparison, if you can use open-cut trenching from the top down, you’re looking at only $300–$500 USD per foot.

When you hit rock during shaft sinking, the last thing you want is a blown timeline or permitting nightmare. That’s why controlled, non-explosive methods (done properly) matter.

How We Help: Non-Blasting Rock Breaking Solutions

When you’re digging down into solid rock, blasting can sometimes not be an option—especially in cities or near sensitive infrastructure. We provide alternative solutions that are safe, fast, and effective:

1. Excavator Splitters
   Hydraulic wedges that fracture rock from the inside out
   • Quiet, vibration-free, and easy to use in tight vertical shafts
   • Perfect for confined spaces like launch and exit shafts
2. Piston Splitters
   Ideal for dense or reinforced rock conditions
   • Provides higher force for larger rock sections
   • Great for precision in areas close to utilities or structures
3. Expansive Grout (Rock-X)
   A chemical demolition agent that quietly breaks rock when poured into shallow holes (as little as 3” deep, up to 20’ or more)
   • Works over time—great for sensitive sites where equipment vibration must be kept to a minimum

Why Contractors Call Rock Busters

We don’t bore tunnels—but we make sure your TBM or MTBM gets to do its job.

From shallow shafts to deep launch pits, our team can provide on-site support with the equipment, product, and expertise needed to break through rock without blasting.

Whether you’re working in a major city or a tight residential neighborhood, here are our top solutions:

• Avoid red tape and permitting delays
• Protect nearby infrastructure
• Keep your timeline on track
• Lower the risk of damaging TBMs or MTBM cutter heads before tunneling even starts

Are You Planning a Tunneling Project? Here’s How to Have a Plan for Rock:

If your geotech report suggests bedrock in the shaft zone, don’t wait until the machine stalls to take care of it. You should have a rock breaking plan ready—especially one that works without explosives.

At Rock Busters, we’re here to help you with a few solutions:

✅ We break rock efficiently
✅ We help stay compliant with city regulations
✅ We hit your project milestones
✅ Wee keep safety a top priority start to finish

Need Support with Shaft Sinking? Be Sure to Call Rock Busters First!

Whether you’re building a subway or laying new utilities, successful tunneling starts with solid shaft prep. If you hit rock, we’ve got your back—with the power, precision, and experience to keep things moving.

Contact Rock Busters today—and let’s break rock the smart way.