Silent TunnelBuster

1. It digs into the ground followed by a tube supplying it with power and digging materials (water and ecobust powder - see link)

2. It digs into the concrete walls of tunnels and inserts the eoobust powder to silently demolish the tunnel.

So how does it work:

For digging, it uses a waterjet head advancing while sucking out the dirty water with an internal tube. Every now and then when reaching somewhere that is difficult to advance, ecobust liquid is inserted and after waiting the 20 minutes or hour for it to break up the area, the TunnelBuster continues on its journey.

When the TunnelBuster reaches actual tunnel walls it then begins traversing the wall and inserting drill holes with ecobust liquid.