Terratec can offer the most versatile hard rock machine available – whether it be new or used. A custom designed machine for specific tunnelling requirements can be supplied for the project in question. High performance is available and by selecting the optional variable hydrostatic transmission cautious advance is still achievable in the most difficult ground conditions. The full breasted, back mounted cutters, afford the operators absolute safety, together with rapid cutter replacement facilities. If a re-manufactured machine is an option, Terratec has set standards that provide the Customer with the requirements of “a brand new machine”. Our dedicated personnel ensure that the equipment delivered to the Customer is of high standard and full reliability. Performance Terratec has developed internal software tools for predicting rock cutting performance. One example is the Rock Cutting Nomograph. The Nomograph is used as follows: 1. Select cutterhead rpm and draw a horizontal line across until it intersects the required cutterhead power; 2. Continue the line vertically upwards from this point until it intersects the required cutterhead diameter; 3. Continue the line horizontally across to the line which most closely represents the local rock strength; 4. Continue the line vertically down until it intersects the selected cutterhead rpm; 5. Finally, continue the line horizontally across to read off the predicted machine excavation rate. Used Equipment Terratec uses a large database of used equipment to locate and purchase these machines so they can be overhauled to meet the specific needs of the customers. Terratec refurbishes and modifies used TBMs to suit all project requirements and gives a full 'as new' warranty on the machine. Terratec can supply hard rock TBMs ranging from 2.60m diameter to 12.50m diameter as well as specialist rock TBMs. Similarly, Terratec designs the corresponding back-up systems essential for the overall performance of the machine.