From hydrodynamic modelling to escape and safety systems, this article will give an overview of the types of testing we undertake to ensure a submarine is safe and contractually compliant throughout its lifecycle. Read on to dive deeper into which elements we test, how and why…
Hullform Design
The hullform design is tested through a mix of physical and computational model techniques – hydrodynamic modelling. This is important to ensure that the submarine will be safe and meet its stated performance characteristics like speed, manoeuvring, control and stealth. Early testing can include experimentation and proof of concept work which feeds into the design process. This leads to early design testing and iterations, to ensure that the final design is as good as it can be to meet the customers’ requirements.
Safe operating envelope (SOE)
Establishing a SOE is a vital part of the submarine development process. It defines what depths, pitch angles and speeds are safe in a given set of circumstances, allowing the submarine operator to remain safe, whilst maximising operating parameters. Early SOEs are established via physical scale models of the submarine and evidence from previous full-scale submarine trials. This is used to confirm computational predictions before the final SOE is determined. Engineers carry out a mix of tests, from proving specific components like the propulsor, to testing the whole submarine model.
Survivability and structure
Survivability looks at the submarine design using sophisticated digital models, to understand what would happen were the submarine to collide or be impacted by an explosion. Design tools allow the assessment of ship design vulnerabilities; however, as is always the case with modelling, it is critical that the limits of what these tools can provide is understood and physical testing is undertaken if needed. The results of this modelling inform the types of material used in the structure, which are then tested later for further assurance.
Environmental and shock testing
Shock testing the durability of a submarine’s individual components ensures they meet the durability standards required of a military vessel. Parts are individually tested to ensure that equipment and onboard weapons can withstand shocks caused by explosions, running aground at speed, or a collision. In a similar fashion, accelerated ‘ageing’ using vibration-inducing equipment is used to test the safety and longevity of energetic materials.
Atmospheres
Nuclear submarine atmospheres (the air that the crew breathes) need to be maintained to acceptable and safe levels for sustainment of life for many months at a time. If the atmosphere cannot be kept within tolerable limits, the submarine would be forced to change the atmosphere in the submarine or, in extremis, return to port for maintenance. Every substance, liquid and material on the submarine can create potential contaminants of the atmosphere which can be harmful to humans, so atmosphere T&E is essential to ensure the health of the crew.
Escape and safety systems
Reducing the risk to life of the ship’s crew in the event of a serious incident is critical, and is the focus of Submarine Escape, Rescue, Abandonment and Survival (SMERAS). Lifesaving equipment is tested in various temperatures, pressures and flood rates. This includes escape suits for crew members, mini submersible rescue craft that can dock with a distressed submarine, and life rafts for surface ships. Tests are undertaken against a stringent set of regulations and processes, incorporating human factors and the participation of submariners.
In conclusion, the multifaceted approach to underwater T&E emphasises its crucial role in enhancing the operational readiness of submarines, providing indispensable insights that guide both their design and deployment. This continuous process not only ensures that each submarine meets stringent safety and performance standards, but also supports the ongoing refinement and adaptation of these complex systems to emerging threats and technological advances.