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Author Topic: Fredrik Granholm's incredibly detailed AIP submarine concept  (Read 1255 times)

Offline covert_shores

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I've been working with retired Swedish submarine officer Fredrik Granholm to publish an article on his 'Porpoise' 1000 ton submarine concept. He's a former officer on HMS Gotland and other boats, a semi-official Swedish Navy submarine historian, engineer and skilled draftsman.So his boat's design is incredibly detailed and well thought through. 3000+ word write up at http://www.hisutton.com/Porpoise_1000.html

Any feedback I can share with him would be very cool. :)

Teasers:





« Last Edit: May 14, 2017, 01:37:05 pm by covert_shores »
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Offline cluttonfred

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #1 on: May 14, 2017, 11:48:16 pm »
Your teaser images are not loading for me, just broken image icons.
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Offline dan_inbox

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #2 on: May 15, 2017, 12:07:46 am »
they load fine here.

Offline minmachine

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #3 on: May 15, 2017, 02:33:01 pm »
Teaser image didn't save for me at first but try this method:
Click on image, then long press on image but instead of choosing save image choose view image, it will take you to teaser image's orignal site and then you can long press and save image.

Offline lastdingo

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #4 on: May 15, 2017, 04:11:48 pm »
(1) two torpedo tubes is awfully few for a sub of this size, regardless of that huge extra tube. This is particularly true if one is occupied by a set of 4 IDAS
(2) flat front and rear walls - is this a thing with submarines? I thought they would need to be near-hemispherical
(3) I don't quite see why the hatches need to be pressurised to the outer skin.
(4) no source of powering the rotation of the fore hydroplanes
(5) tethered floating antennas/sensors seem absent
(6) left and right computer workstation appear to require gymnastics
(7) why would one store the heavy torpedoes above the lightweight command centre? Seems like a poor idea from a roll stability point of view


Offline covert_shores

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #5 on: May 16, 2017, 04:38:48 am »
Thanks for your feedback. I am not the designer but quick answers.

1. 4 tubes plus the FPL which can take a liner for another 4. Some could be loaded with tandem 400mm torpedoes.

2. Flat isn't that unusual these days. Strongly built etc.

3. Outer hull (casing) isn't pressurized, it's mostly free-flooding

4. Just not visible for to location of cross-section

5. See buoyant antenna. Wrote up briefly discusses sensors.

6. ???

7. Torpedoes are close to neutrally buoyant. Location is optimized for diver ops from FPL. Divers can use pure-Oxygen rebreathers more safely if they are less than 7m from surface.
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Offline lastdingo

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #6 on: May 16, 2017, 02:58:06 pm »
Look at the computer workstations. Two of them cannot be reached without climbing over seats.

The outer hull is not pressurised on many sub designs, but the hatches clearly have pressurised cylindrical access to the pressurised inner hull.
This seems wasteful in terms of weight, cost and adds unnecessary potential points of failure.

Offline Volkodav

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #7 on: May 16, 2017, 10:07:30 pm »
Nice, can definitely see a lot of Kockums in there, many of those features have been in service with Sweden and Aust for a couple of decades, while features such as the large centre tube/lockout chamber have been around as concepts at least since the 2000s when I first saw them in tech briefings when I worked in submarine sustainment.

Offline covert_shores

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #8 on: May 18, 2017, 10:26:22 am »
Look at the computer workstations. Two of them cannot be reached without climbing over seats.

The outer hull is not pressurised on many sub designs, but the hatches clearly have pressurised cylindrical access to the pressurised inner hull.
This seems wasteful in terms of weight, cost and adds unnecessary potential points of failure.
do you mean the access hatches going up to the deck? That's how you get in and out. There is one for each watertight compartment in case the center hatches are closed like in an emergency. The third hatch is through the escape capsule. And there is is a forth access portal over the engineering space but I think that's just got maintenance access. Normally it's sealed.

Maybe the seats swivel ;)

Ps. I don't think the outer hull (called a casing in this example) is pressurized on *any* sub designs except some sections of ballast (/regulation?) tanks.
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Offline covert_shores

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #9 on: May 18, 2017, 02:10:08 pm »
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Offline Foo Fighter

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #10 on: May 21, 2017, 02:03:35 am »
The first series of images is of too poor a quality to be of any real use at this end.  Do you have the abilioty to post the originals for download?  It would be easier to make some kind of sense of them then.

Offline covert_shores

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #11 on: May 22, 2017, 03:37:17 am »
High res at the link in the first post. http://www.hisutton.com/Porpoise_1000.html
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Offline Foo Fighter

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #12 on: May 22, 2017, 10:31:37 am »
Sorry, I really have to check properly.  Do you have any further information views of the Type XXIX H?

Offline covert_shores

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Re: Fredrik Granholm's incredibly detailed AIP submarine concept
« Reply #13 on: May 23, 2017, 12:52:17 pm »
Sorry, I really have to check properly.  Do you have any further information views of the Type XXIX H?
Article pending. :)
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