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Silver
12th January 2003, 16:05
Have Hovercraft ever being considered for the Naval Service ?

They would provide the NS with a "quick-response" capability for SAR and other missions.

Goldie fish
12th January 2003, 18:01
Hovercraft are unsuitable in the type of seas and winds we experience around the coast. Their direction of travel is severely restricted by the prevailing wind,and the aircraft engines now used on most larger types are extremely expensive to run and maintain.
They are used by the USMC for beach landings or for estuary work,but they do not preform well in all but flat calm open seas. The hovercraft that used to do the channel run was parked up more often than it was running.
However similar "surface effect ships" which use the principles of hovercraft,but with a boat hull instead of a skirt have been more successful in rough weather but are still in the development stage.
I believe the Airport Fire service in shannon had a hovercraft,but that was useful for crossing the mud flats..
There used to be a place in cork that made hovercraft years ago..naturally they are gone now..
Another disadvantage that a hovercraft has over a conventuinal hull is its inability to loiter. The air must remain trapped under the skirt,therefor the engine must remain running. If it stops,it sinks!
http://www.griffonhovercraft.com/images/375/Shannonairport.jpg
The Shannon Airport Police and Fire service Hovercraft.



Aer Rianta, the owners and operators of most of Ireland's airports, selected the 375TD after a long evaluation of all other hovercraft of this size on the market. This craft will operate over the large expanses of mud and sand which surround the airport at low tide, and provide rescue services to areas which no other vehicle/vessel can reach. Powered by a 83 kW/111hp Land Rover diesel engine, the 375TD is capable of cruising at speeds of 25-30 knots (29-35 mph or 46-56 kms/hr) over many types of surfaces. This particular craft is equipped with two 30 man liferafts and a waterproof VHF/UHF radio/intercom incorporating five helmets. These radios enable the crew to tune into Air Traffic Control frequencies as well as the Fire Service channels. The two liferafts are mechanically jettisoned by the driver and this small hovercraft is therefore capable of rescuing some 65 people. Twelve firemen are being trained to operate and maintain this craft.

http://www.islandengineering.com/images/ses_mu3.jpg
Surface Effect ship.
Norwegian 'Oksoy' Class MCMV (Mine Counter Measures Vessel)

hptmurphy
12th January 2003, 23:02
'scuse me can we have adisscussion on the RNs new River class OPV seing as the KIWIS have decided to buy some.

Goldie fish
13th January 2003, 03:08
Fair enough boss..Where did ye hear about the Kiwis?

Come-quickly
13th January 2003, 14:18
What do you know about the Swedish navy's C-90 combat boat, I just read that they are being adapted for peace keeping/enforcement missions?

Goldie fish
13th January 2003, 15:51
er....Nothing..I suggest you look up www.google.ie!

Come-quickly
13th January 2003, 18:17
This is from:http://www.student.nada.kth.se/~d94-pek/sboat2.html
Combat Boat 90H
There is also a page with a background.

Combat Boat 90Helge is a fast 'assault' boat for amphibious landings in the Swedish archipelago. It's made entirely out of aluminium and the price in 1991 was 5.5 million Swedish crowns each. They are used in the Coast Artillery Amphibious Battalions. One of the most spectacular stunts it can pull of is a complete stop from full speed (30-40knots depending on the boat) in less than two and a half boat lenghts (37m). There are versions with a command center in place of the troop transport, and one boat has been converted into a police boat with 2 beds and a small pentry.



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Lenght : 15.9 m
Width : 3.8 m

Deplacement : 15.2 metric tons fully loaded.

Top speed : 30+ knots fully loaded.

Engines : Two Scania-Vabis DSI14 diesel engines (V8, 14 litres, turbo and intercooler) with a total capacity of 1250hp. It is supposedly possible to change both engines in under 4 hours in an emergency.

Propulsion : Two Alumina waterjets, FF450

Construction material : Aluminium SS 144140

Crew : 3, one PB (sergeant) commander/navigator, one PB second in commander/driver and one GB (furir) machine chief/gunner.

Maximum cargo : 4 tons or 21 men (half a platoon)

Primary Armament : Has changed a bit over time, has been a 30mm automatic cannon in the bow and a 12.7mm machinegun in a ring-mount behind the bridge, two 12.7mm machineguns in the bow and one behind the bridge, the current main armament is as far as I know just the 12.7mm behind the bridge.

Secondary Armament : Minerails with room for 6 mines, and capability for firing the Rb 17 (modified Hellfire) ASM from the stern (from the normal portable Rb 17 launcher).

Navigational system: The CB90H is equipped with an integrated computerized navigational system. The driver and navigator each has a CRT display with radar information superimposed on a digital chart. The navigator can enter waypoints and range circles and the driver-side CRT is instantly updated. This system allows the boats to navigate in zero-visibility at full speed through very tight passages (of which the Swedish archipelago are full).

The computer used is a suspension-mounted Compaq PC with a navigational program from Navi-Sailor and digital charts. A Trimbel 8-channel differential GPS is connected to the computer to provide position updates.
The radar is a Racal-Decca Bridge Master II.

Misc : The CB90H has been tested with a turret containing optical equipment fitted on the machinegun-mount behind the bridge. The system was a Saab Intruments SEOS (Stabilized Electro-Optical System) containing a Thermal Imager, TV camera and a laser rangefinder. It could be upgraded with a laser designator for guiding the Rb 17. Robotsystem 70 with RBS 90 (AAM) has been tested with the CB90. Thanks to low vibrations due to the waterjet propulsion, the system could be fired while underway although with a slight degradation in accuracy.

A improved version of the CB90H called the Enforcer has been built and is undergoing testing, it is equipped with new Volvo Penta TAMD163 P 770 hp engines and is likely to have a 40+ knot top speed.


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Amphibious landings yes, but this seems a little bit over the top.

Drawing of the unarmed export version.(CB90E)

CB90H from the front.

CB90H performing a full stop from high speed.



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Related Interest:
A drawing of YS2000.

Swedish military equipment.

Any further info would be much appriciated, send a mail to d94-pek@nada.kth.se
http://www.student.nada.kth.se/~d94-pek/bilder/SBOAT1.gif http://www.student.nada.kth.se/~d94-pek/bilder/SBOAT2.gif

Goldie fish
14th January 2003, 02:38
Nice,but I dont know how that hull shape would handle in the shannon estuary or Cork harbour in november.....not quite a planing craft..
They Remind me in some ways of the River patrol boats used by the US in the Mekong Delta in Vietnam..similar propulsion system,crew etc..apocalypse now boats..only they were grp..
Where would you be going with that many troops tho? Not much point carrying 2 sections...either 3 or one ..otherwise youll be making a second trip half full..

Would make a Nice launch for the officers from the Base tho...Get them to cobh in time for a few pints in the Comm before the train!
:D