This tender provides the outline specification for UKRI to contract with a single supplier to supply between six- and eleven-disc chopper drive systems to be purchased within the first year of the call-off contract. Future systems procured under this contract would be based upon this specification, but adjusted to meet the specific project requirements, to be agreed at the project’s preliminary design review. The total volume purchased throughout the duration of the contract is likely to be in the region of 20 systems, but this figure cannot be guaranteed.