An apparatus for use in providing an intervention workover control system for an underwater well, comprising a first structure for connecting to a hydraulic flying lead, a first support for supporting at least one electrical flying lead, a second support for supporting the hydraulic flying lead, a second structure, a third structure, and a third support for supporting the at least one electrical flying lead, the second and third structures can be connected to respective ones of opposite sides of the first structure. The structures are configured to provide an intervention workover control system of a first configuration, wherein the first structure is usable with the second and third structures connected to the first structure, and to provide an intervention workover control system of a second configuration, wherein the first structure is usable without the second and third structures connected to the first structure.