MOTHERSHIPS FOR UNMANNED MINE WARFARE—WHY DEDICATED DESIGN IS ESSENTIAL TO SUCCESS

SEA NAVAL SOLUTIONS (SNS): A BELGIAN CONSORTIUM FOR NEXT-GENERATION MINE WARFARE
November 30, 2018
LAUNCH AND RECOVERY OF UNMANNED VEHICLES USING A FLOATING-CRADLE: A SOLUTION THAT TRULY MEETS NAVIES’ MINE WARFARE (MW) NEEDS
December 11, 2018

MOTHERSHIPS FOR UNMANNED MINE WARFARE—WHY DEDICATED DESIGN IS ESSENTIAL TO SUCCESS

Today, mine countermeasures (MCM) are in clear transition to an unmanned future. Leading navies are moving towards “toolboxes”, bringing together sets of high-tech assets to counter ever-more sophisticated mines. While such toolboxes can be controlled from land, full, at-sea operation requires a mothership to act as the system’s lynchpin. Its purpose is to configure, dispatch, and recover unmanned vehicles— but doing this safely and securely, in agitated seas, is singularly challenging. The consequences of error are stark—failed missions and the loss of expensive equipment or life. Like all elements in such a “system of systems”, the design of the mothership is a critical part of the whole: it must be carefully thought through if the major MCM investments contemplated by navies are to yield the desired returns.

 

Key considerations—capability and flexibility

Payload is key: the mothership must be capable of handling the entire toolbox in expert fashion. With assets of the order of tens of tonnes, safe and secure operation in challenging sea states requires a bespoke, highly-tailored platform. This is essential to offer the stability needed, as well as the flexibility to handle a reconfigured or upgraded toolbox—an important consideration given unmanned vehicles’ rapid development. Added to this are numerous more detailed considerations such as propulsion, all of which require rigorous thinking. For example, a dedicated, all-electric design allows the mothership’s motive power to be separated from its diesel source. This means better shock resistance and mastery of noise—all vital for signature control, a central concern in MW.

 

Manoeuvrability—an essential design feature

To handle the toolbox’s assets correctly, the mothership must be carefully designed to maintain the position of its stern—controlling roll, and minimising and absorbing shocks. Failure to meet any one of these requirements may place personnel or high-value equipment at risk. Success calls for a specifically designed propulsion system, such as a combination of vertical-axis propulsion, instantaneous 360° power redirection, and built-in anti-roll features.

 

The seamless handling of unmanned assets

The mothership must also work perfectly with the system’s launch and recovery system (LARS). Conventional ramps and davits rapidly flounder in agitated seas, something that can be overcome by a floating cradle design. While such a cradle recovers and protects the unmanned vehicles, the mothership must hoist them onto deck safely, and secure them—all with a minimum of personnel. To control risks to both people and equipment, this should be effected in seconds from the ship’s interior. But handling goes beyond the LARS: the mothership must also have facilities to reconfigure toolbox assets safely on board. Success here means avoiding conventional approaches, such as overhead cranes or manual handling equipment, and designing specialised hangars, rail systems, and re-rolling equipment. This vision of quiet efficiency is in stark contrast to an image of hordes of personnel struggling with conventional handling equipment on a poorly adapted vessel.

 

Expertise and experience: the keys to good design

The mothership’s designer must bring all these elements together into a seamless whole. And the raft of considerations involved mean that attempting to modify ships designed for other purposes is simply not an option. Partners of choice must have deep and broad design expertise, and strong experience of both military and hydrographic projects. What’s more, specialist MW aspects, such as frigate-level signature control and levels of shock withstanding, are likely to require close and ongoing partnership with relevant defence ministries and agencies.