There have been growing threats of chemical and biological weapons such as the recent incident in the Syria civil war which saw chemical weapons used against rebel armies and civilians. As a result, the Chemical, Biological, Radioactive and Nuclear (CBRN) protection and detection system have been a critical area of emphasis for naval vessels in recent years to ensure crew survivability.

Chemical Warfare Agents (CWA) are broadly categorised into three categories of nerve, blister and blood. Together with CWA, Toxic Industrial Chemicals (TIC) such as Ammonia (NH3), Formaldehyde (CH2O), and Nitric Acid (HNO3) form the full range of compounds that an effective chemical detector requires to detect.

Biological agents can be widely categorised into bacterium, virus, protozoan, parasite, or fungus. One such example is the Anthrax, used in the 2001 United States bioterrorism attack. Effective bio aerosol sampling device is required for early detection and warning as nuclear arms race has been intensified at regions such as the Middle East and the Korean Peninsula. Terror groups have attempted to obtain radioactive material to build them into “dirty bomb”. These nuclear and radioactive threats require devices such as the low and high range Geiger Muller detectors to detect low and high exposure levels, 1 μR1/hr (10 nSv2/hr) to 1000 R/hr (10 Sv/hr) of gamma radiation. With the types of CBRN threats in mind, a shipboard collective protection (ColPro) system which includes real time chemical, biological and radioactive (CBR) detection system seamlessly integrated with the ship’s heating, ventilation, and air-conditioning (HVAC) system can be implemented.

The ColPro system provides a protected area within airtight boundaries referred to as a citadel, which is to be kept at an increased pressure over that of the exterior ambient conditions, preventing contaminants from entering the protected area. High-pressure booster fans, coupled with special Air Filtration Unit (a CBR filter), provide a continuous contaminant-free environment within the citadel.

Figure 1. Typical CBRN Detection System
(Source: Courtesy of Environics Design and System Architecture)

Figure 2. ST Marine’s recent naval and para-military vessels equipped with CBRN Protection and Detection System

Throughout the years, ST Marine has designed and applied CBRN protection and detection system on various military vessels.

One such example is the the design and built of the Al-Ofouq class patrol vessels (PVs) for the Royal Navy of Oman, where ST Marine designed and implemented a fully NATO3 standard compliant CBRN protection and detection system. The PVs are equipped with two main citadels, the forward and aft active citadels, of which two complete sets of 4C, B and R detectors are designed and installed at. There are two sub citadels located in between the two main citadels; these sub citadels are passive, meaning the level of pressurisation is lower than that of active citadels, and they aid in increasing the level of crew survivability at transitional area. These design features provided the PV a fully redundant ColPro system and greatly enhance its war fighting capabilities. Miss Tao Min Yin (Senior Engineer, EDC I – Marine Systems), who was an engineering on the design of the PV, shared that it gives her a great sense of achievement that we are able to design and provide a ColPro system which fulfils user’s operational requirements and meet international standards.

In recent years, ST Marine leveraged on its knowledge and design capabilities of the CBRN protection and detection system and extended the application of this knowledge to other paramilitary and government vessels. This capability is evident when the Singapore Civil Defence Force awarded the shipbuilding contract whereby ST Marine is responsible for the design and construction of the Heavy Fire Vessel, one of the world’s most advanced firefighting boat fitted with CBRN protection and detection system.

The latest design of the Vanguard 120 Frigate developed by ST Marine, is also equipped with the ColPro system, fully compliant with NATO AEP 54 and DNV GL Class notation on CBRN protection and detection.

ColPro System Realisation

With the combined CBRN protection and detection system, a ColPro system mentioned earlier is potentially realised. However, what was not mentioned and is important to the realisation of a fully functional ColPro system is the users’ concept of operations (CONOPS) which form one of the most important design considerations.

The CONOPS of the ColPro system is interlinked and interdependent with the CONOPS of the vessel. The main challenges lie not only in the design of the ColPro system but also in the design of the interfaces and integration of the ColPro system to other systems such as the propulsion system, ship control and monitoring system. The greatest challenge for any designer is the understanding of the shipboard operation requirements for the ColPro system design. ST Marine has collectively mastered this over the years, allowing it to provide a turnkey solution to customers. This also places ST Marine at the forefront of naval ship design and ColPro system design.


1R is the measurement of energy produced by Gamma or X-Ray radiation in a cubic centimeter of air
2nSv is a unit of radiation absorption
3NATO is an acronym for the North Atlantic Treaty Organisation, an alliance of 28 countries bordering the North Atlantic Ocean. It includes Canada, the United States, Turkey and most members of the European Union.
4C, B and R detectors refer to Chemical, Biological and Radioactive detectors