WECDIS & Combat System Interface Unit (WIU CSIU) · Defence Equipment and Support

The National Armaments Director Group, part of the Ministry of Defence, intends to award a contract for the design, manufacture, installation and assurance of a replacement Warship Electronic Chart Display and Information (WECDIS) Interface Unit (WIU) and Combat System Interface Unit (CSIU) (together the Interfaces) to OSI Maritime Ltd (OSI). The contract will be for a term of two years and have an estimated value of £15m (inc VAT).

It is considered that this contract can be awarded under Section 41 of the Procurement Act 2023 because the direct award justification specified in paragraph 6 of Schedule 5 (single supplier - technical reasons) applies.

This is because the WIU and CSIU are required to interface with an upgraded WECDIS being procured from OSI (and which was the subject of a separate transparency notice 2025/S 000-074667 published on 18 November 2025 and both Interfaces need to be integrated into the wider architecture of systems currently installed on Royal Navy platforms, all of which are supplied, supported and assured by OSI.

These include the Electronic Chart Precise Integrated Navigation System (EPCIS) and Warship Automatic Identification System (WAIS). Only OSI has the necessary intellectual property rights, technical drawings and expertise to design, manufacture, install and assure replacement Interfaces which are compatible with existing Royal Navy architecture. There are no reasonable alternatives.

The current CSIU/WIU supplier has been approached to ensure continuity of supply, but the equipment support package which includes an update to the WIU/CSIU component, does not offer value for money and will therefore not be progressed. The Authority considered alternative procurement approaches prior to selecting the proposed route to market.

Following assessment of the available options, OSI Maritime Ltd was identified as the only viable supplier capable of delivering the requirement whilst maintaining compatibility with the existing ECPINS, WECDIS and WAIS architecture and meeting the Authority's technical, operational and safety requirements.