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Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 07:13
by geogen
spazsinbad wrote:100th Anniversary First Shipboard Launch

"Courtesy: Naval Air Systems Command

Watch the first shipboard aircraft takeoff anniversary event held at Patuxent River, Md., that commemorated the day Eugene Ely took off in a Curtiss pusher from USS Birmingham Nov. 14, 1910."

Awesome, Spazs! It would be a true honor if a member of Naval Air Systems Command had read my posted 'Airpower-thread' entry here on under "A Century of ship-operated Aviation". :salute:

From post: "14 Nov. 1910 - Civilian pilot Eugene Ely flew off the Light Cruiser USS Birmingham's makeshift wooden deck as a demonstration of capabilities in his cutting edge Curtiss Model D pusher... the first aircraft take-off from a ship."

RE: Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 07:32
by spazsinbad
The first pic is said to be a landing (on original site) but I think it is clear it is a takeoff.

RE: Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 07:49
by spazsinbad
Linear motor outperforms steam-piston catapults
Replacement for naval-aircraft launch system offers host of tactical and operational benefits
By Terrence Lynch, Northeast Technical Editor -- Design News, October 22, 1995 ... apults.php

"...If approved for production, EMALS would bring a host of improvements to ship design and Naval aviation. With a maximum design thrust of 290,000 lbs, EMALS offers 28% greater launching capability than steam catapults. This improvement may allow flight operations regardless of whether the carrier is turned into the wind. That thrust is fully controllable, allowing compensation for wind gusts and more precise matching of thrust to aircraft weight than is possible with steam. Closed-loop control of thrust will produce less wear and tear on pilots as well as aircraft. By one study, the reduced stress from "soft starts" could extend airframe life as much as 31%."

"...EMALS is a linear induction motor that's capable of accelerating a 100,000 pound aircraft to 240 miles per hour in the space of 300 feet."

RE: Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 08:05
by madrat
If it works that well they should be using them for land-based takeoffs, too. Saves you a lot of fuel on takeoff. Does it give you time to put her back down on the same runway you took off from?

Re: RE: Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 08:13
by geogen
First aircraft landing aboard ship (the armored cruiser Pennsylvania) by Ely...

Jan 18, 1911

RE: Re: RE: Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 08:23
by geogen
And before there was EMALS... they needed to crawl. :)

12 November, 1912. The Navy’s first successful test launching
of an airplane by catapult was made at the
Washington Navy Yard by Lieutenant Theodore G.
Ellyson in the A-3.

RE: Re: RE: Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 08:31
by spazsinbad
Another good source for Cat & Arrest & LSO information is here:

Specifically for this next pic: ... 685823.pdf

Unread postPosted: 23 Dec 2010, 13:00
by StolichnayaStrafer
Imagine being in the first F-35C to make the first launch off of the Ford...

GO NAVY!!! :applause:

Re: RE: EMALS and AAG at PAX.

Unread postPosted: 23 Dec 2010, 16:02
by bjr1028
FlightDreamz wrote:It's my understanding that there are no plans to retrofit the EMAL on carriers built before the U.S.S. Ford (the Ford not needing a retrofit as CVN-78 and up have it built in from the start - obviously). But I wonder how much that would take to replace the steam catapult with an EMAL. I understand electrical power is one possible stumbling block (and limits Britain's carrier(s) to steam if I'm not mistaken). :shrug:

The QEs are electric ships which make them perfect for electromagnetic catapults. They would have to add an auxiliary boiler for stem cats. There's space for one in the design, but it easier to just plug them into the ship's power grid. The increase in reliability and launch rates doesn't hurt either.

The Nimitz-class on the other hand, would have to find a way to harness excess steam into electricity.

Unread postPosted: 23 Dec 2010, 16:07
by jetnerd
StolichnayaStrafer wrote:Imagine being in the first F-35C to make the first launch off of the Ford...

GO NAVY!!! :applause:

Just made me ask myself a question: will there be any serious compromises in fuel / loadout from F-35C's launching from Nimitz class carriers? On doing some quick math (source is Wikipedia, so take the #s for what they are), I am starting to think the opposite. Nimitz carrier ops will be normal, CVN 78 carrier ops more flexible with the greater launch energy from EMALS - i.e. maybe the 5kt over-the-bow launches will be possible. Plus room for internal "growth" (i.e. addition of directed energy weapons, more sensors, etc)

+ F/A-18E max launch wt ~ 66K lbs
- F-35C empty weight ~ 35K lbs
- F-35C Internal fuel ~ 20K lbs
- 2x 2000lb class weapons ~ 4K lbs
= ~ 6K lbs for AAMs, pilot

ps - Spazsinbad - thanks for the link on NavAv history and for finding that Sweetman article. Very interesting.

Unread postPosted: 24 Dec 2010, 01:13
by FlightDreamz
Thanks to Spaz and bjr1028 for the info - much appreciated. So British carriers will accept the new catapults while the old Nimitz class carriers will not (pity). I knew that Englands carriers had room left in the design to accept catapults instead of being strictly STOVL capable, I didn't know WHICH catapult the design left room for.
And Spaz LOTS of useful infomation posted (more so than usual!) thanks for that. :)

Unread postPosted: 24 Dec 2010, 01:46
by SpudmanWP
The new English carrier was dependent on an EMALs systems since it cannot make enough steam of the traditional one.

Unread postPosted: 24 Dec 2010, 02:21
by spazsinbad
The CVF does not make any steam (except in the kitchens):
& ... iance.aspx
_______________________ ... ft_carrier

The MoD decided not to use nuclear propulsion due to its high costs.[29] The carrier's propulsion system will be Integrated Full Electric Propulsion (IFEP). Electric power is generated at 11,000 volts by two Rolls-Royce Marine Trent MT30 36 MW gas turbine generator units and four Wärtsilä Diesel Generator sets (two 9 MW and two 11MW sets). This power is used for both the electric propulsion system and the ship's domestic system. The electric power is used to drive four, Converteam, Advanced Induction Motors, two per shaft and situated in three separate compartments to improve survivability in the event of action damage or flooding. Each 20 MW motor is driven by a Converteam VDM 25000 pulse width modulated converter which produces a variable frequency output allowing the shaft speed to be controlled across the full operating range. The propulsion power management system is integrated fully with the ship's platform management system provided by L-3 Communications. This unique propulsion system eliminates the need for large gearboxes, is compact and by minimizing the number of running generating sets for a given speed is very fuel efficient.

The design places one gas turbine generator unit under each island in the starboard sponson. This relatively high placement removes the requirement for air downtakes/exhausts deep into the ship. Conversely, the Diesel Generator sets are mounted low down in the ship, the weight of these units contributing to the stability of the ship. The unrefuelled range of the carrier will be 10,000 nautical miles (18 520 km)."

Unread postPosted: 24 Dec 2010, 18:46
by bjr1028
spazsinbad wrote:The CVF does not make any steam (except in the kitchens)

But there is space reserved for a donkey boiler for steam cats. EMAL/EMCATs is just the easier and better option.

Unread postPosted: 24 Dec 2010, 20:15
by spazsinbad
Yeah there is going to be a lot of empty space on the CVFs.