Abeking & Rasmussen SWATH patrol ship concept

[Triton]

Model of Aurbeking & Rasmussen SWATH patrol ship concept on display at Euronaval 2012.

Source:
http://www.defence24.pl/euronaval-2012-czy-powstanie-okret-swat-dlugosci-70-metrow/

Via Google Translate:

The aim is not only Euronaval displaying ready-made systems as well as conceptual designs as evidenced by the issuance by the German company Abeking & Rasmussen patrol ship model SWAT and the hull length of 70 m

In contrast to well-known to us a series of five double-hulled patrol ships for Latvia the new unit is to be more than ten times the displacement (over 2,000 tons) and the ability to take on board a brand new weapon.

First of all, it was assumed that the new ship will be equipped with a helicopter landing pad weighing up to 12 tonnes, and Unmanned Aerial Systems for vertical take-off. Abandoned hangar building at the landing, and the aircraft after landing to be immediately lowered the elevator to the service zone located below the deck. Zone at the aerodrome is also prepared to use the boat ? inspection, to be dropped from the aft deck.

All equipment on board is to have a modular structure. On the bow prepared a place for the two containers required for the particular task at a time and one equipment module "artillery". Similarly, you can easily assemble the upper deck equipment, both in relation to weapons systems and surveillance systems technology.

This is of course only a draft, and so far he loses supporters in Germany with standard single-hull vessels. However, the improved maritime SWAT units offer hope that soon this class and size of the double-hulled ships will be introduced to a more open innovation naval forces.

 

[Jemiba]

Is this necking a new hydrodynamic refinement for those hulls ? Still yet, I've only
seen contrary form, where the hull is thickened, giving it a kind of bottle shape.

 

[TomS]

You mean the pinched section of the underbodies? It's been used in some SWATH designs for a long time (it's used in Sea Shadow, for example). I think it's a form of area-ruling, though my knowledge of hydrodynamics isn't good enough to explain exactly why it's used

 

[Jemiba]

Thanks, you may be right. It's hard to see on photos of the real Sea Shadow, but several modellers
seem to have better information (like this one http://thegreatcanadianmodelbuilderswebpage.blogspot.com/2010/07/sea-shadow.html )
and , yes, the diameter of the hulls actually is reduced somewhat, before it becomes bigger again.
I thought, that one of the drawbacks of the SWATH concept are the cramped hulls, so making
them even narrower seemed counter productive to me. ???

 

[RP1]

Re: Abeking & Rasmussen SWATH patrol ship concept: Hull Shape


Hi,


"I think it's a form of area-ruling"


Pretty much; From the Froude number you can select the required Cp for minimum resistance. This defines a shape that varies from dog-bone (fat ends) through parallel to fat middle.


- RP1