The Wärtsilä Sternguard In-Water Serviceable Seal (IWSS) is a fully underwater serviceable seal. This provides segments including commercial, cruise & ferry, merchant and in-land waterway vessels with opportunities to reduce down-time as there is no requirements for dry-docking, habitat usage and shaft withdrawal. This reduces costs as there is no requirement to drain the stern tube oil or aid and transfer vessels to a dry dock slot. In addition, there is no need to unload cargo for an underwater overhaul. The pressure springs ensure a continuous pressure between the lapped surfaces and enables axial movement of the static section. A sealing device exists inside the static section, which prevents lubricant leakage during axial movement. This seal is available partially split for installations with shaft removals in dry dock, but also fully split for in-water overhauls or dry dock installations. The Sternguard IWSS has been designed to provide a reliable and faster service as well as improved operational performance. Environmentally Acceptable Lubricants (EALs) and mineral oil lubricant are accepted and the seal is compliant with the 2013 US EPA Vessel General Permit rules.*
