Tunnel boring machines

P. 1
Tunnel Boring Machines (TBM) are the epitome of pipejacking power, control and accuracy in an array of soil conditions.TBMs are suitable where manned entry is permissible. Akkerman TBMs can be used with any jacking pipe up to 14-feet (4.3 m) in diameter and a mu

P. 5
and blasting is restricted or forbidden and tunnel boring machines (TBMs) are too bulky. First, a horizontal pilot hole is drilled, with the aid of a directional drilling system if necessary. When the pilot bit breaks through, it is removed and replaced with a reaming head