Heavy Air Landing Seabase Ship


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11 March 2006
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There were a number of interesting concepts put forward early this decade creating a major sea bases from carrier-like modules. I also came across this HALSS - anyone know if this is a project or programme?


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Looks similar to the Short Take-off and Landing Floating Airport (STOLPORT) developed by Seaforth Maritime Ltd. of Aberdeen in the 1970s/80s. It was to be moored in the North Sea and handle DASH-7s carrying personnel to/from Aberdeen for onward transfer to production platforms. "Sunk" by Bristow's Tiger and British Airways' Chinook, if I recall.

Or even earlier, the Habakkuk.

You could almost write a book on Sea Basing, it has been going on for so long. A **lot** of designs have been proposed, using everything from off-the-shelf merchantment to spar bouys and ships that up-end themselves. Several different configurations have been proposed that use a series of Semisubmersible units (twin hulled vessels used for some offshore oil fields) that are connected together to allow operation of a/c up to C-17 size.

Sea Basing itself is a fundamental part of the USNs "Sea Power 21" concept. It is such a wide subject that a large number of designs and technologies are being considered (and some actually developed and used), in order to get some idea of the nature of the possible solution space.

Google for "Sea Basing" and you will find many design concepts.

Sea-basing is prehaps not specific enough, I have plenty on that. My focus is around the concepts for MOB (mobile offshore base) and HALSS. These concepts represent some real challenges to naval architects - if not offshore exploration design teams, as it was these firms that also received funding to do some preliminary design work.

Internet, will only take you so far, and most of my key information in these concepts is not internet sourced...so its about opening up an issue to see if anyone can help...prehaps out of the industry or access to other journels I have not seen.

Most interesting part of the MOB is the way modules are put together, and the means to keep these modules level enough for aircraft operations.

I have attached a quick review of some of the MOB's being considered at the preliminary design phase.


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There is no reason why these designs should not have a Ski-jump!
After all like with the Harrier, it would afford the likes of the C-130's (shown in the HALSS artist impression) better payload/range/take off performance, which will be critical.
After all I think there would be no problem with the venerable Hercules to handle ski-jumps!

Indeed the Sea Basing effort has been going on for a long time. Even the Army has become involved in Sea Basing. It has been working for a couple years now on a concept called Afloat Forward Staging Base. The intent is to take container ships and build flight decks on them to allow for a very good sized flight deck for rotorcraft to fly off of. Of course since they are not gray hulls there is concern with how to protect them. The effort is moving forward slowly.
MOBS article here http://www.history.navy.mil/nan/backissues/1970s/1972/oct72.pdf found here http://www.history.navy.mil/nan/backissues/newbackissues.htm
Now that *is* interesting - that's much older than I thought!
Please see the following global security pages -

As well as the following PDF
http://www.popularmechanics.com/technology/military_law/1281531.html ( for good measure)
Link on Seabasing concept (6 MB .pdf file)

And another...

Here are a couple of pics of possible Maritime Prepositioning Force ships that can be included in the sea basing concept. Got the pics from here I think http://peoships.crane.navy.mil/pms325/mpff.htm


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Artist's view (top) of one of the five semi-submersible base units--each 1000 feet (305 m) long--that would be assembled to form the Mobile Offshore Base (MOB) in this McDermott (Babcock & Wilcox) concept. The assembled MOB could provide an operating and support base for aircraft when land bases are not available. However, in many respects, the Sea Base concept has overtaken the MOB.

Artist's view (bottom) of the assembled MOB. The shortcomings of the MOB include its lack of mobility and the time required to deploy and assemble.

Source: The Naval Institute Guide to the Ships and Aircraft of the U.S. fleet by Norman Polmar, US Naval Institute, 2005.


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Given current events, the MOB might be yet another concept making a comeback.
Sea-going base concept press photo circa 1968 found on eBay.



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