Cutting is the Key for the Perfect Trench

Published: 30/9, 2019

At a jobsite in Assamstadt, Germany, Schwarz GmbH used a Rockwheel cutting unit for the very first time. The Rockwheel D20 was perfect for their trench excavation and other supply lines.  

The project called for expanding a storage building for a woodworking company. Foreman Oswald Lienhardt decided to use a Rockwheel D20 for trenching on this project due to its 39-in (100-cm) width, which ensured accurate work to achieve the desired dimensions without any costly filling work. Machine operator Jochen Kalinkas ran the Rockwheel fast and accurately through the layered rock soil. 

Before using a Rockwheel, the company used a hydraulic hammer as well as a ripper tooth for excavation and trenching. Using these attachments for this kind of work creates a funnel shaped trench, which often leads to undesirable breakouts and significant filling work on the side walls.  

Instead of ripping or breaking the rock the Rockwheel cuts through the material and leaves an even sidewall structure, working up to five times faster than a ripper tooth or a hydraulic hammer. The low noise and low vibration level of the Rockwheel means it can be used in residential areas without causing significant nuisance for the neighborhood.  
The construction team found the precision and quality of the outcome particularly impressive.  

“With the Rockwheel I can mill off just 1 cm if the foreman asks me to do so,” says Kalinkas.  

Approximately 1,575 ft (480 m) of trenching was performed with the Rockwheel D20 in the layered clay rock soil. 

 “Another great advantage of the Rockwheel is the reusable excavated material”, says Lienhardt. “It is almost like gravel and can be used to back-fill the trench later.” 

When filling the trench, the homogeneity and the consistency of the material are the main factors, determined by the grain size and mixture. The Rockwheel leaves a consistently small-sized grain similar to gravel, which can be used directly for refilling the trench. When solidifying the soil the uniformity of the material plays an important role in preventing the emergence of bumps or sink holes on the surface once the ground settles.