Electromagnetic Aircraft Launch System (EMALS)?

[stepwilk]

An ex-USN friend just asked me if the EMALS, currently entirely experimental but well beyond the blue-sky stage, is a viable replacement for the steam catapault, which is currently reaching the end of its lifespan aboard many CVs.

Is it woo-woo or the real deal? Opinions?

[VinRouge]

if someone can do this

YouTube - Homemade Gauss Gun (http://www.youtube.com/watch?v=UNMyfNq8onE)

YouTube - 8 KJ Hand-RailGun (http://www.youtube.com/watch?v=GdYxzn8B9z0&feature=related)

in their home, I am sure the USN can use it to launch ships.

[Solid Rust Twotter]

Suck all the fillings out of your teeth and deposit them in your underwear on launch. Going to be loads of fun....:}:ok:

[NWSRG]

It's really just a linear electric motor...and as such, can generate large and sustainable torque almost instantly...certainly viable for new CVNs...

[petit plateau]

Bull**** warning: this is all based on memory of chats with people designing electromagnetic stuff and I don't know much about project status and this is a rumour network.

There's a UK R&D programme and a US R&D programme.

The US R&D programme is well funded and the carrier development pathway pretty much demands it. They are not having huge success.

The UK R&D programme had its life support switched off (it was just on last I heard, but no news since then which is normally a bad sign) and the F-35 option for CTOL pretty much depends on it working (if you think about the attractiveness of bunging a boiler in a CV at short notice even if designed for/not with). The R&D programme was pretty successful.

The UK industrial group (Converteam et al) would like to move to the next stage of hefty sized trials because they had reason to think they solved some control problems plaguing the other lot. The MOD is convinced a catapult won't be needed (i.e. desperate to avoid a decent AWACS budget) and desisted.

Pretty normal for UK industrial strategy.

This issue affects the French as well for obvious reasons.

Hope this helps. If anyone who does know can tell that would be appreciated.

[GreenKnight121]

Well, since the EMALS is currently scheduled to be installed in all 4 catapult positions on CVN-78 Ford when it commissions in 2015, I think it is a bit more than experimental... at least in the eyes of the USN.

[TheInquisitor]

Hmm....very strong EM fields and modern electric jets...not a good combo methinks, even worse with weapons loaded, surely? Or am I not giving the R&D guys enough credit for already overcoming this obvious hurdle?

[0497]

bump.

Successful manned launch.

Navy Launches Pilot With an Electromagnetic Shove [Updated] | Danger Room | Wired.com (http://www.wired.com/dangerroom/2010/12/navy-launches-pilot-with-an-electromagnetic-shove/)

[draken55]

A more detailed article now on the AFM website.

EMALS first launch: key.Aero, Military Aviation (http://www.key.aero/view_news.asp?ID=2876&thisSection=military)

If the US Navy is so far down the development line for it's new CVN-21 carriers, why on earth would the UK even consider duplicating their efforts by designing a bespoke system for QE/POW? :uhoh:

[Not_a_boffin]

They wouldn't. But - a number of obstacles remain to be overcome, largely in how any UK system would be charged. On a CVN there's plenty of watts available from the kettle to charge up the 150MJ needed to get your aircraft off the deck.

The QEC is different, in that the main distribution grid also provides the propulsion, so managing the power demand through the control system will be the hard part. We can use the General Atomics linear motor bit as is, we'll just have to be a bit clever as to how the storage flywheels get charged and how the system is balanced. That's probably where Converteam as DA for the power system will come in...

The EMC issues have (obviously) been known about from day 1, which is why the 3/4 scale demonstrator at Lakehurst is busy checking the effects on Bugs now.

[draken55]

Not a boffin

Thanks for the very detailed explanation of the problems.

I was aware that the QEC was designed to be flexible and allow conversion to "cats and traps" in future should the need emerge. However, it's the implementation of this change now and not during a much later refit, that makes the UK's unique problem an issue to be resolved sooner.

Hopefully the EMAL cat will function as specified and any EMC issues will also be resolved within this new time frame.

[fleigle]

Here is the youtube video of a few launches.
Link c/o Flightaware.
YouTube - Navy launches first aircraft using EMALS (http://www.youtube.com/watch?v=euLsg_viWW0)
f

[ORAC]

Ares article with various links. Bug Zapper (http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3a27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3a6d9e65d5-5add-447a-9a6e-f091e645c472&plckScript=blogScript&plckElementId=blogDest)

The US Navy performed the first aircraft launch (http://www.navair.navy.mil/NewsReleases/index.cfm?fuseaction=home.view&id=4468)with the Electromagnetic Aircraft Launch System (EMALS) on Saturday, December 18. An F/A-18E Super Hornet was launched successfully from the ground-based prototype at the Navy's Lakehurst, NJ, test facility.

It's an important milestone for a technology that is now critical to the future of both the US Navy and Royal Navy carrier forces. The US Navy's next carrier, CVN-78 Gerald R. Ford, is well past the stage where reversion to steam catapults would be economical, while the UK's switch to the catapult-arrest F-35C version of the Joint Strike Fighter depends on EMALS, because the turbine-electric Queen Elizabeth-class carriers do not have any steam generating capability.

We reported in June's DTI (http://www.aviationweek.com/aw/generic/story_generic.jsp?) that EMALS seemed to have put most of its problems behind it, with the first successful no-load tests in April. Program people said at the Navy League show in May that the first live launch would take place around year-end, and - encouragingly - it did.

The schedule is still quite tight, because components for the Ford's catapults are due to arrive at the Newport News shipyard in May 2011. Some of the most time-critical components - the 80,000 pound power units - are scheduled to reach the yard the day before they are hoisted aboard the ship.

EMALS will allow Ford to launch both heavier and lighter aircraft - it is not only more powerful than steam catapults, but can also be "dialed down" to launch lighter, more lightly-built aircraft such as future UAVs. However, the strategic usefulness of this capability will be limited for some time, because there are no plans to retrofit EMALS to existing carriers.

General Atomics is the prime contractor for EMALS. In the long term, the dream is to use solid-state energy storage (http://www.dtic.mil/descriptivesum/Y2010/Navy/0604512N.pdf)(the same technology behind the Navy's railgun) but the current system uses 12 power units (six for each pair of catapults) with flywheels and motor-generators. The power units spin up to high speed and then convert to generators to energize the linear motor.

The UK has its own subscale EMALS demonstration program (http://www.dtic.mil/descriptivesum/Y2010/Navy/0604512N.pdf)run by Converteam, which provides the primary electric generators (http://www.converteam.com/.../Queen_Elizabeth_Class_Aircraft_Carriers_datasheet__GB.7008.g b.05.09.02_.pdf)for the carrier. (A contract issued to Converteam this summer was an early clue (http://www.aviationweek.com/aw/blogs/defense/index.jsp?plckController=Blog&plckBlogPage=BlogViewPost&newspaperUserId=27ec4a53-dcc8-42d0-bd3a-01329aef79a7&plckPostId=Blog%3A27ec4a53-dcc8-42d0-bd3a-01329aef79a7Post%3A096beaa2-4af3-46bd-aeaa-e6f4fcda3e5e&plckScript=blogScript&plckElementId=blogDest) that the UK was about to dump the F-35B.) The RN is likely to go with General Atomics hardware for the catapults, but Converteam could be involved in developing a different power supply system.

This is not actually the first aircraft launch system to use electric power or flywheels. The US Navy's second and third carriers - Lexington and Saratoga - used steam turbine/electric propulsion and were equipped with flywheel catapults, spun up by electric motors. The catapults, installed on the hangar deck, were rarely used and eventually removed - for everything you ever wanted to know about catapults, read here (http://www.americanheritage.com/articles/magazine/it/2006/4/2006_4_26.shtml).

[LurkerBelow]

The use of linear motor catapults has been around since the 1950s.
I recall reading about something like this in one of my Dad's magazines
(he had a vast collection of Popular Mechanics and the like).
Various things that I recall was the energy requirement was met by
a motor / generator set with a very large flywheel. Heating of coils
and the expansion of the track were major issues.
As with a lot of such articles, you never found out why the
technology was never adopted although in this case I could
imagine the problems (think large copper coils in a marine
environment, big heavy rotating mass in a ship)
Completely different proposition today with power electronics and the like.
However, the steam catapult is a very interesting piece of
machinery and has a lot of cunning design features

[Pontius Navigator]

The QEC is different, in that the main distribution grid also provides the propulsion, so managing the power demand through the control system will be the hard part.

"Right ho Caruthers, 30 kts across the deck, ready to charge EMALS."

"Aye, aye Sir."

"Whooa, why have we stopped?"

"All the power went to the EMALS Sir."

:)

[draken55]

Cancel launch! Bombheads to waist cat - Please:{

http://i1084.photobucket.com/albums/j420/draken55/AirBritain20.jpg

[Not_a_boffin]

PN

Yep, that's pretty much it, see T45 for less severe example of power system imbalance....

[Tourist]

Plus issues with precession must surely make hard work for the bearings and/or move the ship funny in a big sea?

[Pontius Navigator]

Ouch, and I was joking.

[Not_a_boffin]

If you were joking, you'd have said something like "a seal walks into a club...."

[GreenKnight121]

In 2005 EMALS was expected to require around 6.5 MW to recharge the high-power energy storage system that actually provides the 300MW launch surge.

While that may have changed some, I don't expect it to have changed a lot.


CVF has a significant surplus of generating capacity as designed (two MT30 GTs @ 36MW each & two 9MW and two 11MW diesel generator sets), totaling 112MW... the propeller shaft motors at full speed will only draw off 80MW of that.

It also had "space & weight" reserved for either 1 or 2 more MT30s, but this feature was last mentioned some years ago, and it is not clear if they can still be fitted.

[Jetex_Jim]

Put steam cats on it and a hydrogen peroxide plant. It worked for the V1 and the first steam cats were copied from V1 launch technology.

[Not_a_boffin]

GK - I don't think it's changed either. The difficulty is "balancing" the grid while the two 6.5MW loads drop in and out and the propulsive load fluctuates, which means designing the control system software to accommodate this from the off. Perfectly feasible - just a risk to be borne in mind.....

What isn't feasible, is adding more DG or GT. The ship just doesn't have room in the relevant compartments, but unless you're changing the propulsion motors and upping the speed, shouldn't need any more anyway.

[LowObservable]

Draken -

Now that is a scary photo... particularly if something goes wrong and you have to consider the consequences of jettisoning umpteen bangy things in front of the big grey floaty thing that doesn't stop or turn very quickly.

[Tourist]

LO

Luckily, the bangy things have a wonderful property when immersed in water called "sinking" which fortuitously solves the problem for the grey floaty thing.....:rolleyes:

[GreenKnight121]

U.S. Navy Resumes EMALS Tests - Defense News (http://www.defensenews.com/story.php?i=6913462&c=AME&s=SEA)

U.S. Navy Resumes EMALS Tests

Flight tests of the U.S. Navy's new electromagnetic aircraft launch system (EMALS) resumed in late May after a five-month hiatus, and two more aircraft types have now passed their initial launch tests.

The program's maiden launches were accomplished in mid-December when an F/A-18E Super Hornet strike fighter from Air Test and Evaluation Squadron 23 (VX-23) made four takeoffs from the Navy's catapult test center at Lakehurst, N.J. But the tests revealed the need to fine-tune the software that controls the system's motors and better control the miniscule timing gaps between when the motors are energized and turned off.

"The linear motors fire sequentially as you go down the catapult track," said Capt. James Donnelly, the Navy's program manager for EMALS. "Only three are energized at a time. They turn on, turn off. As each one energizes, a force is exerted on the aircraft, and the timing needed to be fine-tuned."

Flight tests with the F/A-18E resumed May 25, and "the launches validated the software changes," Donnelly said.

The Super Hornet made 14 launches using the revamped software, followed by 12 launches on June 1 and 2 with a T-45C Goshawk training jet from VX-23.
A C-2A Carrier Onboard Delivery aircraft from VX-20 made a further series of 12 launches on June 8 and 9.

The Super Hornet will return in July to Lakehurst for another series of launches using a variety of stores, or weapons, mounted under the wings and on the aircraft. Later in the summer, an E-2D Advanced Hawkeye airborne command-and-control aircraft will begin launch tests, Donnelly said.

The multiple launches are used to test a variety of weights on the aircraft, he said, and to validate the EMALS system and improve reliability. The aircraft are also tested at various launch speeds.

Reliability of the EMALS system is "improving," Donnelly said.

"We have more and more launches without any [warning] lights that come on, anything we annotate in launch logs," he said during a June 23 interview.

"A lot of corrections" were made during the early stages of the program's flight testing, Donnelly said.

"We're doing much less of that. We had very few issues in the May and June launches."

The EMALS, under development by prime contractor General Atomics and the Navy, is intended for installation on board the new Gerald R. Ford CVN 78-class aircraft carriers, where they will replace traditional steam catapults. The launch tests are done at Lakehurst using a mixed Navy-General Atomics team.

Despite the five-month pause in the test schedule, production and delivery of EMALS components is proceeding for the Gerald R. Ford, nder construction at Huntington Ingalls Industries' Newport News, Va., shipyard.

"No impact to the ship [construction] schedule," Donnelly said. "We're meeting our required in-yard dates. We started deliveries in May, and we're delivering a lot of equipment this month, including most of the motor generators - the components that many folks were most concerned about schedule-wise."

Asked about the program's budget performance, Donnelly noted that production elements are being procured under a fixed-price contract - "no ups and extras there," he said - but he declined to provide test budget figures.

"We're constantly looking at the testing budget, so that's under discussion," he said.
"The bottom line is, we'll continue testing," he said. "Our focus is to ensure the catapult is as reliable as possible as when we deliver and the ship gets underway with sailors aboard."

[Halton Brat]

The naval version of the Wiggins Aerodyne naturally pre-dated the development of the Steam Catapult for Carrier operations (in fact, it also pre-dated the Carrier, which somewhat hindered the development of the aircraft).

When Carrier ops finally started, the only way to launch the contraption was by means of a bungee rope, which was secured to the bow of the ship. However, in low wind-over-deck scenarios, the imparted energy was found to be insufficient; many Aerodynes & their crews were lost when they trickled over the bow & into the sea, only to be immediately run down by HM War Canoe. These tragedies led directly to the development of the angled Flight Deck, one of the several positive contributions to naval aviation due to the Aerodyne.

However, in the hiatus prior to the construction of Carriers with the angled Deck, a novel but precarious solution was found. The end of the bungee rope, which was normally secured to the bow of the Carrier, was instead secured to the stern of a Destroyer which steamed a Cable-length ahead of the flat-top leviathan.This was not entirely successful however, as several Aerodynes were ripped in half by the surfeit of energy now on hand, their bewildered crews left sitting on the deck surrounded my much wood & string. A further mishap occured when the Destroyer HMS Bumnbaccy was cleaved in half by the Carrier during this fraught operation, when the Carrier's Captain was distracted by his Wardroom bill.

These collective disasters provided the impetus therefore, for the development of the Steam Catapult; a great British invention which stands alongside Gravity in merit - both much admired & utilised by the less technologically-advanced nations of the world.

HB