POTUS wants to scrap EMALS on Ford class CVNs

kinnem

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Not sure why. What's wrong with controlling costs and continuing with a reliable system that's been working for years? If it ain't broke, don't fix it comes to mind. But then I'm no naval aviation expert, so perhaps you can educate me on why it's such a bad decision?
 

FMHS-79

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I'm by no means an expert, but here are a couple of of paragraphs on EMALS from Wikipedia.

Compared to steam catapults, EMALS weighs less, occupies less space, requires less maintenance and manpower, is more reliable, recharges more quickly, and uses less energy. Steam catapults, which use about 1,350 lb (610 kg) of steam per launch, have extensive mechanical, pneumatic, and hydraulic subsystems. EMALS uses no steam, which makes it suitable for the Navy's planned all-electric ships.

Compared to steam catapults, EMALS can control the launch performance with greater precision, allowing it to launch more kinds of aircraft, from heavy fighter jets to light unmanned aircraft. Each one of the four disk alternators in the EMALS system can deliver 29 percent more energy than a steam catapult's approximately 95 megajoules; each disk alternator can supply up to 121 megajoules. The EMALS will also be more efficient than the 5-percent efficiency of steam catapults​

From what I've read from other sources, there are indeed long-term advantages and cost savings associated with the move from steam to EMALS. I've seen that it EMALS has been installed and tested on the Ford, so not sure how moving back now would save cost (but do not see the same data that POTUS does).
 

scoutpilot

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Not sure why. What's wrong with controlling costs and continuing with a reliable system that's been working for years? If it ain't broke, don't fix it comes to mind. But then I'm no naval aviation expert, so perhaps you can educate me on why it's such a bad decision?

Why invent the car? Just breed stronger horses and faster buggies!
 

kinnem

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Why invent the car? Just breed stronger horses and faster buggies!
Exactly! :D
No, when there is the order of magnitude of difference then by all means proceed. I suppose there may be an order of magnitude of difference between steam and EMALS... I don't know. But general costs and bang for the buck are different arguments from the technological aspects. There is no way for me to evaluate the decision that appears to have been made, but it doesn't seem to be an unreasonable one.
 

Physicsguru

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Launching systems aren't modular add-ons. Steam systems require piping, accumulators, steam generators, actuators, as well as the piping from the heat source (reactor). EMALS is just as complicated, with the electrical wiring, switches, busses, not to mention the catapults themselves. Gerald R. Ford already is at sea doing pre-commissioning trials, and John F. Kennedy is scheduled to be launched next year. To go back to steam systems would require them to be installed on Enterprise, which would mean a redesign of the ship, involving delays and cost over-runs.

Now, why EMALS instead of steam catapults? Efficiency. Steam catapults are heat engines, which use expanding gas to do the work. The maximum efficency of an ideal heat engine is only around 30% to 35%. Also, steam cats apply maximum force at the start, and fade out at the end of the run. EM systems have much higher efficiencies (80-95%) because there is much less energy loss to heat. Also, the force can be controlled and programmed for the length of the shot, so it minimizes stresses on the airframes.

Yes, there are development costs, but in the long run money is saved in energy efficiency, less wear and tear on the airframes, and lower maintenance costs. The technology works, as seen in the shore testing. There are always glitches in all systems in sea trials; that's why we have them.
 

Capt MJ

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Now I have to go and do research on all this. I am always interested in tech advances, especially after being on the USS ZUMWALT commissioning committee and seeing Star Wars meets Star Trek technology on there...and then hearing of the propulsion breakdown in the Panama Canal. Major paradigm shifts come with major risks, and the challenge is knowing when to move forward and defining acceptable risk.

I wonder if the new system is any quieter...
My DH swears his ability to sleep anywhere regardless of noise is because his stateroom was often located under a cat, where he enjoyed the steam's thump and whoosh at any hour during flight ops.
 

DesertCaliMom

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The project is already over budget, what's a few billion more to retrofit steam? [emoji23]
 
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kinnem

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OK. So educate me again. Why would carriers with EMALS not retain their EMALS system? Why must they be retrofitted?
 

FMHS-79

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DJT indicated he was upset with reports of problems with the new Electromagnetic Aircraft Launch System, or EMALS, which is an integral part of the new Ford-class carriers and "going to *******ed steam". In order to comply with that directive, the Navy would need to retrofit...

IMHO, this is a significant over-reaction to issues commonly faced when deploying a new system.
 
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