KBS Maritime have a requirement for penstock replacements at B Lock within Portsmouth Naval Base. The project consists of 10 in number replacement penstocks in 6 chambers overall. The penstock system controls sea water via a culvert system between the harbour, the basin and the dry docks. These include levelling penstocks of circa 8 metres deep to drainage penstocks circa 18 metres deep. The replacement programme will replace the current cast irons doors with new with specification to be agreed along with the associated shafts, wedges, door nut, brackets, platforms, ladders and actuation and road plates. This project is due to commence in Q4 2026 with all to be replaced by Feb 2030. Contractors must be able to demonstrate design, manufacture and installation of penstock replacements in a marine environment including all site management under CDM regulations and competency of Health and Safety compliance and safe practices. Contractors must also possess at least five years' experience working within a marine environment. Contractors who do not provide suitable and sufficient evidence of this will not be considered