Concept submarine with external rim-drive pumpjets


Research + illustration
Senior Member
31 October 2014
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This s one of my own thought exercises. Open to challenge and discussion :)

US Navy and Royal Navy nuclear-powered attack submarines (SSN(X) and SSN(R) respectively) will refocus on deep-water anti-submarine operations. While being hugely capable boats, this will take them away from the littorals where many of today’s submarine operations take place. They will be used less in inshore ISR (Intelligence Surveillance and Reconnaissance), Special Forces support and Land-Attack.

This concept could fill that void and provide a bridge to coming age of extra-large combat Unmanned Underwater Vehicles. In this role the Future Submarine will operate as a host platform for an array of unmanned vehicles of various sizes. The boats could also fulfill time-consuming officer training and system testing duties which also detract from SSNs’ operational capacity.

At the same time the Future Submarine must have smaller crews, partly due to recruitment and retention challenges.

Full write-up

Quick notes:
a) twin rim-drive pump jets
b) SDV hangar in tail. Can also carry large UUVs
c) Optional AIP (Air independent Power) and VLS modules
D. Lithium-Ion batteries in hull-forming bundles
E. Minimum height sail with non-penetrating telescopic electro-optical periscope and EW masts folding into upper part of sail. Shorter non-penetrating telescopic masts (radar, surface comms etc) in sail.
F. Conformal bow sonar, possibly without access tunnel
G. Low frequency passive sonar along lower hull
H. Retractable towed arrays integrated into lower X-form runners
I. Torpedo warning sensors fore, beam and aft


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The idea of a SDV/UUV hangar in tail is an interesting one. Any idea if this has been explored elsewhere?
GTX said:
The idea of a SDV/UUV hangar in tail is an interesting one. Any idea if this has been explored elsewhere?

It was in one of the USN's Forward Pass Studies, at least.,6343.0.html
And also SMX-31 ( and HDS-500 ( but not on this scale.

In the 1960s the RN and RM considered using the aft torpedo tubes on A-Class subs for SDVs but project faltered due to costs (even though it was peanuts) and typical requirement rewriting
Nice work.

Bit concern about the possible "on-way" maintenance requirement for the Rim thruster as the concept seems make the propulsor motor no longer accessible from the hull. But we'll see if technology would allows for the "maintenance free" sealed propulsor concept. If this being the case the propulsor would be sealed, with only power and control cable protruding out. It will last as long as the submarine itself or be replaced entirely during overhaul which can be like every 5-10 years.

The concept of deploying the UUV also interesting, but my concern is mainly on retrieval. Like if the UUV has no tether cable, how we can guide it back to return to the sub.
Yes agreed exactly re rim-drive. The caveat is exact that. But *if* they can be maintenance free (and such configurations aren't new in themselves), then it massively frees space in the pressure hull.

Polish DPV firm Seacraft have immersed electric motors. See might be interesting tech for this. But my working assumption is maintenance free sealed units.

Re UUV recovery. Several ways, but aft-facing hangar right in stern is easier not harder. The gray block below the SDV is a cradle rack which extended out the back. An automated buoy winch which would raise the buoy cable for the UUV to attach to and ride down to dock, before being rolled back in. Same for SDVs. If sub is bottomed, then maybe even swim the UUV in, with or without divers.
One concern is that the cradle is cantilever, but hoping that it can take the weight.
I've updated the article ( with more info on launch/recovery.

Key to attached:
A) Outer streamlined doors.
C) Recovery buoy with hook.
D) Automated hatch and outer doors.
E) Vehicle securing trap on cradle runners.
F) Diver lurk.
G) Doors to diver lurk.
H) Three-person lock in / out trunk.
I) Mission space including main Special Forces accommodation.
J) Cradle.
K) Winch on cradle runners.
L) Larger diameter hatches for ease of mid-size UUV, Special Forces gear and casualty movement.


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