Wave piercing bow designs seem to be all the rage these days but this video released a few days ago by Damen Shipyards demonstrates a simple truth.
www.youtube.com/watch?v=4A-U5GQQ1hk
Small ships bob up and down in big waves.
This cannot be good for endurance and ultimately, effectiveness in choppy conditions.
It is a vast simplification but…
big = stable = flexible = effective
And before anyone mentions it
www.youtube.com/watch?v=a09ujXkis6I
www.youtube.com/watch?v=JXiPM0j2VBg
www.youtube.com/watch?v=K9x4-HIuylw
www.youtube.com/watch?v=w2gmOBk7RPU
www.youtube.com/watch?v=6Emzr1FHF0Q
www.youtube.com/watch?v=4IPk0OjiS_M
www.youtube.com/watch?v=F-oCDOaBhGk
But for a bankruptcy, there may have been more T-AGOS-23 (USNS Impeccable):
http://www.navsource.org/archives/09/66/6623.htm
Disappointing that your videos did not include British naval use of SWATH: https://www.youtube.com/watch?v=a09ujXkis6I
Anixtu, that is because I didn’t know :)
Am going to update the post right now !
OK, the sofas on the patrol boat still had their palastic covers on
… But what is the huge empty deck for?
I’m sure I’ve seen a VSV wavepiercer hiding behind an MOD shed somewhere? http://www.boatdesign.net/forums/attachments/boat-design/7977d1151586435-concept-50-foot-deplacement-vsv_mkiii.jpg
Is that called the FIC (functionally)?
Or has the manufacturer already changed (looks much better now, but could be the picture angle)?
http://www.dailymail.co.uk/news/article-465664/Marines-unveil-stealth-boat-latest-weapon-war-terror.html
ACC – quite a different beast. The wavepiercer was shown on local TV news down in the South when it was a prototype without a customer (the RM must have been watching because they bought it and it vanished from public sight). If I remember the description right it had two very big Penta engines, went at racing powerboat speeds but through waves not over them, and as a result needed an extremely thick armoured glass cockpit screen to take the impacts without shattering. I also seem to recall it bellowing like a very angry bull – with the booming engine noise, the explosion of spray around each punch through the waves, and a speed that would embarrass most racing craft, I doubt this would be called stealthy.
There was, in the 80s, an idea in powerboat racing circles that punching through waves would waste less energy than bouncing off the tops. The design they considered I suppose you’d call SWASH? As in a knife-blade like hull between a single submerged machinery hull and an above surface crew hull. As far as I recall it was really effective providing the wave height didn’t exceed the height of the narrow knife-blade bit. But once the waves were too big the crew hull became a sledgehammer trying to break waves and it a) slowed down a lot, and b) risked breaking up. I guess the VSV was the refined technical solution that actually worked even in heavy seas.
TD
I have been banging on about this for ever.
A lot of ‘Patrol work gets carried on in coastal waters that are open to the ocean on one side and can get very rough indeed.
Th Irish recognised this with the increased size of their patrol boats, and years ago restricted their aviation ship to the Irish sea coz it ‘bobbed about’ to much. Instead their wish list of an Absalon style vessel is born in part from their experiences on the western coasts.
This wanting 1500 ton or less patrol ships is to my mind (unless your operating in very enclosed waters) born of not understanding that point.
Big Dutch patrol ships all round?
Chris
Just out of interest. The VSV which was supposed to be replaced or maybe just supplemented by the Project Belle FIC is still around as it can be seen on the latest 2014 Google Earth imagery sitting in the car park at the south western end of Hamworthy Camp.
BMT Nigel Gee designed the Fast Sea Frame on which Sea Fighter is built:
http://science.howstuffworks.com/sea-fighter.htm
Very similar to DK Brown’s SWATH thoughts, albeit without a lift to hangar their organic helicopters.
Daniele – clearly they move it about a bit then: http://binged.it/1zUa8KE
Ah! Well spotted. Funny place to leave it?
Probably makes it easier for the scrap wagon to pick it up!
I thought they planned to stick an 8×8 chassis underneath it and sell it to the USMC…
The USN had a private company design this SWATH ship ,the Sustina . It had a centre section that could lower itself then deploy a ramp to off load its cargo. It would do this after beaching itself and the strengthening for this was enhanced to give it an ice breaking ability for northern waters. The vessel was built and tested but rejected in the end by the USN and sold as a ferry to the Alaskan government to run between islands without docking facilities for conventional ferries. Think of it as a latter day LST.
http://gcaptain.com/wp-content/uploads/2012/09/Screen-shot-2012-09-25-at-12.08.07-PM-635×419.png
@ACC – USN SEALS keep buying these:
http://foxtrotalpha.jalopnik.com/unmasking-the-columbia-rivers-mysterious-stealth-boats-1583093889
I’m sure it’s just a fluke. :D
Kent, misread which Columbia, and thought the SEALs would finally replay the “Mission in Columbia” using some proper kit:
http://foxtrotalpha.jalopnik.com/the-patria-nemo-mortar-boat-is-small-and-fast-with-a-hu-1666492358
@ Monkey – Google “buyexploreryachts.com” and go to “Brokerage”…it’s for sale, poa… :-)
GNB
“Small ships bob up and down in big waves.
This cannot be good for endurance and ultimately, effectiveness in choppy conditions.
It is a vast simplification but…
big = stable = flexible = effective”
Does this mean:
a) We can finally shut down any nonsense talk about replacing frigates with patrol boats, corvettes and coracles, and,
b) Stop all whinging about the size of the carriers?
Hallelujah!!!!