The TERRA-HAMMER T 055 SK is an extremely popular and powerful machine with a length of 1.04 m (3.4 ft). It is suitable for most trenchless applications.
A Trenchless contractor in the Netherlands required the length of this underground piercing tool (mole) to be reduced to 0.90 m (3 ft) without any reduction of power. The request was based on the fact that in the Netherlands most of the sidewalk flagstones are 0.30 m x 0.30 m (1 ft x 1 ft) .
Using a 0.90 m (3 ft) long piercing tool the contractor would only need to remove three flagstones. Whereas using a longer piercing tool four flagstones are needed to be removed, requiring a longer and more expensive starting pit of 1.20 m (4 ft).
The Swiss engineers of TERRA AG successfully designed a very short new (B-36) end cone. This makes the T 055 SK "mini" only 0.90 m (3 ft) long. All other components of the piercing tool such as the main piston (striker) and the machine body remain the same. Thus the machine retains its full power.
The machine is also exceptionally handy where the exit pit is too small to take the piercing tool out as the reverse speed has also been doubled, allowing the machine to be reversed back to the entry pit to achieve faster lateral connections.
The reverse is controlled by a simple ¼ turn of the air hose, which is locked during operation by means of the patented S version pneumatic lock – an innovative TERRA invention. Being a version K, the Machine is able to be opened without heat for servicing, and as with all TERRA moles there is a 3 year warranty for the main piston - still unique worldwide.