Would not a steam catapult imply steam turbine propulsion?
Would've been nicer if you could've pointed me to a peer-review source. But I did some search of my own. One source I found (1995) claims that steam catapults have an operational energy limit of 95 MJ. The same paper provides a figure with tow force over time, peaking at about 210 kilopounds, or 930 kN. Given a catapult cylinder length of 101m, that comes up to 94MJ, which sounds consistent. Again, taking the 2.8 second launch time, we get 34 MW power for the steam catapult.
For the EMALS the source states a 122 MJ launch energy, or 43.5 MW average power. Now for the actual input power, I couldn't find a clear number. The source mentions that 4 flywheels will be necessary, each with a peak power of 81.6 MW and 121MJ of energy storage. So by that logic, no sane number of gas turbines could meet the instantaneous power requirements.
Compare this to the steam catapult: the authors mention that the steam catapult is only 5% efficient? This would imply 1.9 GJ of required input energy per launch.
The 60MW figure for EMALS is all over the internet.
Would've been nicer if you could've pointed me to a peer-review source. But I did some search of my own. One source I found (1995) claims that steam catapults have an operational energy limit of 95 MJ. The same paper provides a figure with tow force over time, peaking at about 210 kilopounds, or 930 kN. Given a catapult cylinder length of 101m, that comes up to 94MJ, which sounds consistent. Again, taking the 2.8 second launch time, we get 34 MW power for the steam catapult.
For the EMALS the source states a 122 MJ launch energy, or 43.5 MW average power. Now for the actual input power, I couldn't find a clear number. The source mentions that 4 flywheels will be necessary, each with a peak power of 81.6 MW and 121MJ of energy storage. So by that logic, no sane number of gas turbines could meet the instantaneous power requirements.
Compare this to the steam catapult: the authors mention that the steam catapult is only 5% efficient? This would imply 1.9 GJ of required input energy per launch.