Following on from this week's long read on AFV modularity, a short post on another modular approach at a lower scale, but with nonetheless interesting implications and options - Moog's RIwP modular turret.
RIwP (pronounced "rip" without the w) is a neat concept - a modular weapon station that is completely agnostic to what weapons and optics are fitted to it, as well as to what platform it is fitted. That doesn't immediately sound too exciting and at risk of being a marketing spin on just having options on the order form, but the key with RIwP is that the modular elements are quite tightly defined and so could be rapidly hot swapped in the field to responsively refit vehicles with weapon and sensor systems on a mission to mission basis, or where that might be a bit aspirational, offer a path to rapid upgrade and capability evolution at very minimal cost and complexity versus buying new turrets.
The core of it is the RIwP Common Cupola to which you then plug the major mission oriented components. The cupola does not penetrate the deck, reloadable from under armour and is reasonably space efficient with a 1 m ring diameter - in the Stryker application configured for MCWS it has allowed all roof hatches to remain accessible.
Weapons wise its normally a gun in the centre (plus coax if desired) with anti-tank guided missiles, anti-aircraft missiles, guided and unguided rockets and other launchers including tube launched UAS like the Coyote variously fitted to the sides. There have been some interesting configurations with a missile pod in the centre too, and we've seen directed energy weapons both in the centre station and as side mounts. Its fairly open to any reasonable combination.
The sensor suite can be swapped out too, generally for differing capabilities of sensor head at the front right of the turret, but other sensors can be fitted including hunter/killer configured dual sight heads when moving into larger weapon calibre configurations.
Survivability wise it is a STANAG 4569 Level 3 (7.62×51mm AP direct fire and 155 mm High Explosive at 60 m for fragmentation/blast). Its a relatively small and unmanned turret, so protection is relatively arbitrary - optics, exposed weapons and ammunition feeds will get damaged regardless of the turret's protection, so this is a perfectly good level to sit at.
Whilst the preferred platform is realistically a 6x6 AFV and upwards (and tracked equivalents of course), it can go on lighter vehicles, having been trialled down to an Oshkosh M-ATV. At lighter weights there will be limits on weapon fits and issues around roof reinforcement and rollover stability that would need to be considered and mitigated. They've actually tried it in quite a vast range of configuration and platform combinations, its at Technology Readiness Level 9 and has secured a few (mainly air defence) US contracts including Army CUAS, IM-SHORAD, Marine Air Defence Integrated System (MADIS) Increment 0.1 and Containerised Weapon Station - Heavy (CWS-H). It's also competing for the Stryker Medium Calibre Weapon System (MCWS) Enhancement programme.
Back to the modularity - the sales pitch is you could hot swap in the field. Its a few minutes to remove and fit an alternate pod on the sides, and not much different to replace the sight heads. The broad theory was in an Army like the US Army with huge scale of resources, there is plenty of room for the many 'idle' (in an operational sense) solider at a base location to be leveraged to fit and adjust RIwPs for vehicles coming and going.
Realistically that wouldn't work with more resource constrained armies, and there is a reasonable argument that the real world appetite is unlikely to be there for this kind of approach, not least the carriage of many weapon systems and associated munitions that may or may not be needed or used.
More compelling to me is the far more real application for very easy 'plug and play' upgrades and the implications thereof. Just like my arguments for whole vehicle modularity on Boxer, RIwP would allow a force to procure the basic configuration they need cheaply and rapidly to start, and then very cheaply spiral in new and more specialist capabilities over time. If a force decides it needs an anti-air capability it will often procure all new platforms in most cases (ideally of the same base platform as something else they have, but UK and others are a prime example of tending to buy myriad bespoke fleets for each requirement).
With something like the RIwP approach, you instead buy a new weapon system that conforms to the RIwP requirements for electronic architecture and interfaces (which are GVA based) and has the straightforward RIwP mounting element on the side and then its available as an option to be fitted to any of the turrets you already have, you don't even need any new vehicles necessarily, or if you do its more of the same, not something new. As with the Boxer discussion, it opens you as a user to a lot more innovation from industry, and gives you a lot more agility and vastly lower risk and resource cost to obtain capabilities.
An interesting capability in all that espouses that same modular approach as Boxer does on a whole vehicle level, giving quite a lot of potential flexibility at an operational level (which like Boxer would probably not be realistically used much) but also opens a door to fast and cheap capability development and acquisition (which like Boxer would be hugely valuable and absolutely is a big benefit over other approaches).