US Navy's Electro-Magnetic Catapult..

[Silversmok3]

Link here;http://www.globalsecurity.org/military/systems/ship/systems/emals.htm

Its a magnetic launch system that replaces the steam catapult that's been used since WWII ...

I wonder what it feels like to get shot off the ship with one of these magnetic cats.Its being built into the USS Gerald R. Ford,which is slated to have her keel laid late in '09.Should be interesting...

 

[clint g]

one step closer to rail guns

 

[Forbin]

I wonder what it feels like to get shot off the ship with one of these magnetic cats.

Would it feel any different?

 

[John Picard]

one step closer to rail guns

Do some checking. The rail gun does exist and has been demonstrated. There is video on the web from the company that has been working with DARPA to develop it -- and it is bad ass

 

[Alpha_Geek]

I'd have to wager that the mag cat is engineered to perform as similar to the steam cat as possible to reduce any training time for flight and deck crews.

I don't think I'd be carrying my credit cards on the deck.

 

[Chaos Descending]

I'd have to wager that the mag cat is engineered to perform as similar to the steam cat as possible to reduce any training time for flight and deck crews.

I don't think I'd be carrying my credit cards on the deck.

I wouldn't think so anyway.

They'd be a FOD hazard.

 

[SeerSGB]

I'd have to wager that the mag cat is engineered to perform as similar to the steam cat as possible to reduce any training time for flight and deck crews.

I don't think I'd be carrying my credit cards on the deck.

I wouldn't think so anyway.

They'd be a FOD hazard.

True, but are they going to use to jimmy open the cockpit when they lock the keys in inside?

I wonder though, about the EM-Cats: What about avionics and shipboard electronics? Would repeated use "leak" EM into the ship's hull or just foul up shit in general?

 

[Forbin]

Yes, of course, the Navy has committed to a device that they didn't know ruins multi-million dollar aircraft electronic suites. I'm sure they've had absolutely no one checking into that throughout the years-long development and testing process.

 

[USS KG5]

I wonder though, about the EM-Cats: What about avionics and shipboard electronics? Would repeated use "leak" EM into the ship's hull or just foul up shit in general?

One would assume that the equipment would be fairly well shielded against EMP anyhow, but "systems integration" in the design of the carrier would deal with most such conflicts.

Lets face it, it is unlikely that the engineers designing the carrier have not looked very carefully into the issues of using a magnetic catapult.

 

[Timo]

Yes, of course, the Navy has committed to a device that they didn't know ruins multi-million dollar aircraft electronic suites. I'm sure they've had absolutely no one checking into that throughout the years-long development and testing process.

Well, integration is a difficult business. Plenty of embarrassing screw-ups there, such as the self-defense ECM on the B-1B that was extremely good at jamming itself. Such things take a lot of realistic prototyping if early problems are to be avoided: doable with things like backpack radios, tanks or small fighters, but rather expensive with big bombers, and it's something you just have to skip when building a big seagoing vessel. Plenty of horror stories about major fire control systems that just plain didn't agree with their platforms, for example. I do hope there won't be big surprises ahead with these neo-rubberbands.

Timo Saloniemi

 

[Dale]

They've been using sush systems to launch roller coasters for years... and they're just now installing it on aircraft carriers?

 

[Timo]

The little difference being that an aircraft carrier isn't hooked up to a power grid usually. Devising an electric system that spares enough oomph from the frankly not all that powerful reactors of the ship to the catapult that has to haul much bigger loads than the amusement park ones is not trivial - the Nimitz wasn't really designed with electric power to spare.

Steam to spare, OTOH... That goes without saying on any steam turbine vessel like that. So why fix what ain't broke?

Timo Saloniemi

 

[Dale]

The little difference being that an aircraft carrier isn't hooked up to a power grid usually. Devising an electric system that spares enough oomph from the frankly not all that powerful reactors of the ship to the catapult that has to haul much bigger loads than the amusement park ones is not trivial - the Nimitz wasn't really designed with electric power to spare.

Steam to spare, OTOH... That goes without saying on any steam turbine vessel like that. So why fix what ain't broke?

Timo Saloniemi

Point taken, though I am surprised to learn that such a system would tax the nuclear reactor on an aircraft carrier.

 

[Timo]

Not really the reactor, but the power chain past the turbines. So far, there has been no real reason to convert any appreciable fraction of the ship's power into electricity; it would have gone directly into propeller rotation through the geared steam turbines. There wouldn't exist massive spare capacity for new electricity hogs, then - although once one finally decides on EM catapults, those can no doubt easily be accommodated.

The modern trend is to instead create powerplants (nuclear, gas turbine, diesel, whatever) that primarily produce electricity, which then gets applied on stuff which almost incidentally also includes the drive engines. Still, even the new Ford class CVN is supposed to retain direct nuclear-mechanical propulsion, although it will dedicate more capacity to onboard electric systems such as the catapults and possible EM weapons and railguns (although none of the latter are officially projected for the class).

Timo Saloniemi

 

[John Picard]

The little difference being that an aircraft carrier isn't hooked up to a power grid usually. Devising an electric system that spares enough oomph from the frankly not all that powerful reactors of the ship to the catapult that has to haul much bigger loads than the amusement park ones is not trivial - the Nimitz wasn't really designed with electric power to spare.

Steam to spare, OTOH... That goes without saying on any steam turbine vessel like that. So why fix what ain't broke?

Timo Saloniemi

Those reactors put out quite a bit of power. The "trick" is that the catapult has to be able to launch a 20-ton(?) aircraft from zero to 200knots in two seconds. Also, the steam driven system requires a lot of maintenance during a deployment (plus it's hotter than hell up there when the ship is in the IO) whereas the EM should reduce down time.

Also, everyone here is concerned what an EM pulse would do to the system. Hell, the birds won't launch, let alone much of anything else working

 

[Alpha_Geek]

Meh, run the mag cat controller on tubes, it'll work just fine.

An EM pulse will damage some semiconductors such as diodes, transistors, and chips (it causes the boundary of the internal layers to go a bit wonky), but other electrical systems will work fine after the pulse is over.

AG

 

[John Picard]

^^ I'm betting they're smart enough to shield the entire system.

 

[USS KG5]

^^ I'm betting they're smart enough to shield the entire system.

One would imagine EM shielding is in place anyhow - the carriers have a full NBC suite do they not?

 

[Forbin]

Yes, of course, the Navy has committed to a device that they didn't know ruins multi-million dollar aircraft electronic suites. I'm sure they've had absolutely no one checking into that throughout the years-long development and testing process.

Well, integration is a difficult business. Plenty of embarrassing screw-ups there, such as the self-defense ECM on the B-1B that was extremely good at jamming itself. Such things take a lot of realistic prototyping if early problems are to be avoided: doable with things like backpack radios, tanks or small fighters, but rather expensive with big bombers, and it's something you just have to skip when building a big seagoing vessel. Plenty of horror stories about major fire control systems that just plain didn't agree with their platforms, for example. I do hope there won't be big surprises ahead with these neo-rubberbands.

Timo Saloniemi

True dat. We built an EW suite for the F/A-18 that was stressed to take plenty of Gs beyond what the aircraft normally encountered, but it failed every time it went thru an actual catapult launch. We eventually discovered that the bulkhead it was mounted to also mounted the nosewheel brace strut on its opposite face. When the cat yanked the nosewheel on launch, the force on that point of that bulkhead was something like 90 Gs. Back to drawing board!

 

[Alpha_Geek]

Yeah, I was mostly being silly about EM and the mag cat.

That being said, the SIGINT people were amazed when they cracked open that MIG-25 that defected to Japan and discovered a radar set built out of "acorn" tubes.