In one of our previous blogs, we mentioned that Survival Load is an important Operational Requirement for naval defense systems. Now it’s time to dive deeper into these requirements. What is Survival Load, why is it so important for naval defense systems and how are elongation and stretching connected to it?
By understanding more about these concepts, you’ll have more grip on your sonar cable design as an engineer. An important asset if you have to validate your naval defense system to the customer.
Survival Load: making sure your naval defense system stays operative
As an engineer, your main goal is to ensure that the naval defense system you deliver works at all times. Even more than with other underwater systems, downtime must be completely ruled out.
This makes the Survival Load absolutely crucial. The Survival Load covers exceptional conditions and is about surviving under certain circumstances. What conditions can the cable withstand without failing?
Especially during the aforementioned defense missions, conditions sometimes occur that are not standard for cables. For example, the naval sonar cables must be prepared for heavy wave action and storms, as missions will continue despite rough weather.
Defense ships are also often stationary during missions, which causes the cable to sag. The cable sinks deeper than its usual depth. In deeper waters, the pressure is higher, which causes the load to become higher. Once the boat departs afterward, the cable is subjected to a higher tractive force. The sinking and pulling of the cable must be included in the Survival Load. After all, the sonar cable must not fail during the mission.
Submarines, in turn, often "lay down" close to the seabed to not draw attention during the mission. This can cause the sonar cable to scrape across the seabed.
In short, a Survival Load that is prepared for various exceptional circumstances is often a requirement for naval defense systems.
Stretching of sonar cables
An important aspect to consider in exceptional situations is cable stretching. However, stretching is taken into account by default in the cable design.
Our cable designers take into account how far material can stretch without permanent deformation. Load on the cable will cause it to stretch, but once the load is gone, the material will bounce back to its original position. However, the material deforms plastically if the load is too high and cannot spring back to its old position.
The danger of permanent deformation is already partly eliminated by using a helix structure in sonar cables (which makes the cable more flexible), but this absorbs the stretch only up to 0.6%. This means that in the cable design the maximum stretch can be extended to 0.6% without permanently deforming the individual components.
Strategic Partner: covering the right Survival Load
Whether it is the stretching capabilities of a cable or other exceptional circumstances in which the cable is going to be used, defense engineers usually know what their cable needs to be able to do and what is required. However, there may be special cases for which there is not yet a specific solution.
These exceptional cases drive our cable designers to develop new solutions. Especially with new orders or new issues, you encounter in the field, our specialists are happy to think along with you! They can help you select the right materials, and even conduct tests to prepare the cable for various conditions.
So, what is your challenge?
Schedule your Feasibility Check for advice
The challenges you encounter in projects can vary greatly. After all, you can't always influence the customer's requests and what specifications they want to be incorporated.
As mentioned earlier, our experts are happy to think along with you about all kinds of different challenges. But is your customer's request feasible? Or is there perhaps a smarter solution that costs less money and/or effort?
In a Feasibility Check, you discuss these questions with a cable specialist. Schedule your Feasibility Check here:
With all other questions about your cabling needs, you can contact my colleagues or me here. Our cable experts are always happy to help, advise or guide you in all your cable requirements.