History, Politics And Current Affairs

warshipadmin wrote: ↑Sun Aug 16, 2026 10:25 pm The steam catapults are a lot bigger than the EMALS and need a steam buffer, and a lot of pipework. So retrofitting steam catapults is essentially a complete redesign between the flight deck and the keel. So 10 years. Fun factoid each launch uses the same energy as 4 gallons of diesel. The steam is desalinated water so you vastly increase the water usage. The catapults are only 5% efficient.

brovane wrote: ↑Mon Aug 17, 2026 2:53 am

warshipadmin wrote: ↑Sun Aug 16, 2026 10:25 pm The steam catapults are a lot bigger than the EMALS and need a steam buffer, and a lot of pipework. So retrofitting steam catapults is essentially a complete redesign between the flight deck and the keel. So 10 years. Fun factoid each launch uses the same energy as 4 gallons of diesel. The steam is desalinated water so you vastly increase the water usage. The catapults are only 5% efficient.

Wasn't one of the reason for going to EMALS that it allows you easily vary the catapult force from a unmanned drone to a fully load Super Hornet?

Nik_SpeakerToCats wrote: ↑Mon Aug 17, 2026 1:51 pm Steam catapults are okay, but the plumbing 'tail' is horrendous.

Bit like pneumatic 'dynamite' guns, their time seems to have passed.

Especially with so many systems now demanding more and more electrical power, ranging from Radar, via anti-drone 'microwave' and 'laser' zappers to electric-driven CIWS turrets and their feed systems, to possible future rail-guns...

MilSpec seems to shun electric side-thrusters and 'podded' drives, but their time will come.

Snark:
I'm surprised 'King Coal' hasn't had a word in that trumpet-like ear to suggest reversion to trad stokers...
/

Nightwatch2 wrote: ↑Mon Aug 17, 2026 3:01 am

brovane wrote: ↑Mon Aug 17, 2026 2:53 am

warshipadmin wrote: ↑Sun Aug 16, 2026 10:25 pm The steam catapults are a lot bigger than the EMALS and need a steam buffer, and a lot of pipework. So retrofitting steam catapults is essentially a complete redesign between the flight deck and the keel. So 10 years. Fun factoid each launch uses the same energy as 4 gallons of diesel. The steam is desalinated water so you vastly increase the water usage. The catapults are only 5% efficient.

Wasn't one of the reason for going to EMALS that it allows you easily vary the catapult force from a unmanned drone to a fully load Super Hornet?

so can steam

brovane wrote: ↑Mon Aug 17, 2026 10:29 pm

Nightwatch2 wrote: ↑Mon Aug 17, 2026 3:01 am

brovane wrote: ↑Mon Aug 17, 2026 2:53 am

Wasn't one of the reason for going to EMALS that it allows you easily vary the catapult force from a unmanned drone to a fully load Super Hornet?

so can steam

Is this not accurate?

For low-weight drone aircraft, the Electromagnetic Aircraft Launch System (EMALS) is vastly superior to traditional steam catapults. EMALS uses a software-controlled linear induction motor that allows precise, low-end thrust tuning, whereas steam systems deliver a violent, rigid power surge that can tear apart or over-stress lightweight, fragile unmanned airframes.

kdahm wrote: ↑Tue Aug 18, 2026 2:43 am I believe, although I'm not certain, that the issue is that steam catapults have a certain minimum impulse, and they have a definite acceleration jolt at the beginning. It's because of releasing high pressure (comparatively) steam into a cylinder arrangement, and getting enough force to get the piston and carriage assembly moving. Also, because the cylinder is constantly expanding, it requires additional steam regardless of the weight of the plane.

In contrast, the EMALS system can be tuned, can have a fairly low acceleration throughout it's travel regardless of the weight of the plane, and the acceleration is much more proportional to plane weight. That means that a drone can start off slow and increase acceleration down the track and the minimum energy used is much lower.

warshipadmin wrote: ↑Tue Aug 18, 2026 3:52 am So far as the jolt goes, what is it like compared with the controlled crash at the end of each flight? Apparently the airframes don't have a defined number of takeoffs before being torn down or replaced, unlike say civil airliners where the number of pressure cycles is logged.