Every torpedo tube is the portal between the dry storage of some useful payload, and the wet medium through which that payload will travel to its ultimate destination. It is also, and this is the more important bit, a fixed size, which constrains exactly what the Navy can put inside and launch from the tube. A new project by the Office of Naval Research seeks to find a way around that limitation.
Specifically, the Navy is looking for a way to use torpedo tubes to launched Unmanned Underwater Vehicles, or UUVs. The immediate answer at the heart of a Small Business Innovation Research request is a “UUV Sabot System,” or UUVSS. The ultimate design will be defined by constraints. First, there’s the dimensions of the torpedo tube: 21-inch diameter, 25-feet-long, and ending in an “ocean interface.” The sabot is to be a guide through that passage and transition, separating from the vehicle once the vehicle has left the tube.
The sabots can be either expendable or reusable, which will alter their function in a key way. ONR wants expendable sabots to eject from the torpedo tube alongside the underwater robot, and the reusable ones to remain in the tube through the launch and then be recovered internally. The sabot will have to accommodate sea drones that are 12-inches and 18-inches in diameter, and do so with launches at depths of up to 100 feet below the surface.
There’s more in the full list of project requirements, but what stands out is how this isn’t just a desire brought about by advances in robotics. It’s also a request that’s only possible because of progress in materials sciences. This isn’t just about launching robots from torpedo tubes, it’s also about building miniaturized pumps and inflatable sabots that make robot-launch-by-tube even possible, using new textile technologies and modeling of fluid interactions.
The project fits into a broader plan to find ways for submarines to serve as platforms and motherships for smaller robots. One proposal for a different project looked at ways to modify vertical launch tubes on Virginia-class submarines, converting another port for projectiles into a home for robots. The sabot system would allow torpedo tubes to function similarly, making a human-crewed submarine not just an asset unto itself, but a host for a whole array of maneuvering and scouting machines.