Aircraft Catapults

[NOMISYRRUC]

If navies really wanted to launch heavy aircraft off small ships, then just skip the catapult piece and mount the rocket to the airframe ZELL style...

Don't worry Gerry's got your back...

In the 1980s there was a comedy sketch show on Channel Four called "Who Dares Wins".

It included a sketch where an American general was interviewed about the Strategic Defence Initiative in which he said the USAF wanted to hire "Britain's greatest space engineer... Gerry Anderson!" because if anyone could make it work it was him.

 

[NOMISYRRUC]

The General also said that President Reagan wanted Lady Penelope's telephone number.

 

[Arjen]

Settled. That was Sylvia Anderson's telephone number.

 

[orlovsky]

For a 151' cat, you're talking Phantoms with regularity. Though Super Crusaders would probably be a better fit (bigger margin for error and less worry about hot and humid conditions)

Assuming a 30% improvement you do get into Spey Phantom territory yes its take off speed was 130 knots at 50,000 lb I understand? A 30% improvement gets you for 50,000 lb at 91 knots to 50,000lb at 104 knots, roughly the same with the BS5A of Eagle and Ark Royal. Now can you avoid the Spey Phantom completely? At a similar improvement you'd be getting 120 knots from the BS5A replacements

135 knots for 52,000 lb is indeed , take off speed after all. A more interesting question is whether you can avoid spey and stick to standard F-4J in Eagle and Ark Roayal and the answer is... probably still no? If there is a 30% power improvement you can launch a 50,000 lb aircraft at 120 knots up from 105 knots. F-4J needed 176 knots IMS?

F-4B with normal and extended nosegear:

Subtract 3 kts for drooped ailerons (F-4J and late and retrofitted F-4Bs)
Add about 5 kts for 104°F.

 

[NOMISYRRUC]

Settled. That was Sylvia Anderson's telephone number.

The joke was that President Reagan thought Lady Penelope Creighton-Ward was a person not a puppet.

 

[Arjen]

I got that

It's just that in an interview, Gerry Anderson said that not only did his wife provide Lady Penelope's voice, the doll itself was modeled on her as well.

 

[carvalho2008]

why not ce-2 sats system with 6 degree ski jump?

For small carriers or multifunction plataforms can be a simple solution.

For exemple, think about the Korea Project ....

CE-2 Catapult system + Ski jump

The two J-79 engine (now F-414) can be installed under ski jump

First, fighters can be used to take off without a catapult when configured for air defense only. The catapult is only needed to set up heavy attacks

Easy maintenance, operation and the ski jump would work as a redundancy in case of catastrophic failures, the ship does not stop operating, despite reducing some capabilities for attacking long distances or cargo
think about the HMS Hermes with this configuration or the Colossus class. The take-off problem would be satisfactorily resolved and other issues such as stored air-naval fuel could then be considered.

 

[orlovsky]

Which end speeds does the ce-2 give at typical carrier stroke lengths of say 150-300 ft?

 

[carvalho2008]

Which end speeds does the ce-2 give at typical carrier stroke lengths of say 150-300 ft?

It's hard to find detailed information, but an F-4B at 55,000 pounds, 100o.F Day, and 1450 feet is quoted. The catapult could be upgraded up to an A-3 at 78,000 pounds. An A-4 used a full load of less than 1,100 ft. One model ce-2 made repetitive launchs off a 28.000 pounds aircraft in excess off 225 knots on just such an extension.

However, we must consider that in a hypothesis of combined use of a catapult CE-2 (modernized) added to a ski jump, it only has to provide the additional percentage of impulse related to the percentage lag of a ski jump compared to a classic catapult steam or emals. The ski jump supplies 100% of the needs of a fighter in an air defense configuration. It only has a delay when the fighter is configured to attack (30%), full of bombs. More than one turbine can be attached to the catapult gearbox.

It must also be considered that the sats system, being terrestrial, has the requirement of takeoffs with zero relative wind and obstacles of 50 feet high at the end of the runway threshold.

The Ski Jump Is the Future

When the F

www.usni.org

 

[carvalho2008]

Russian project 23000E has ski jump + catapult

 

[GTX]

Nice model...doubt we will ever see it in real steel.

 

[publiusr]

I might want one steam and one electric…

 

[zen]

Russian project 23000E has ski jump + catapult

Interesting, seems the catapults are flat and stop before the ski-ramp.

 

[Archibald]

Trying to pin down the Essex that got the real deal: the C-11 catapult. They were the SCB-27C plus the usual "outsider" Oriskany, so - 7 of them.
Is that correct ?

Ship​	Decommissioned​
USS Oriskany (CV-34) ​	September 1976​
USS Hancock (CV-19) ​	January 1976​
USS Intrepid (CV-11) ​	Mar 1974​
USS Ticonderoga (CV-14) ​	September 1973​
USS Shangri-La (CV-38) ​	July 1971​
USS Lexington (CV-16) ​	November 1991​
USS Bon Homme Richard (CV-31) ​	2 July 1971​

Seven received the SCB-27C upgrades: Intrepid, Ticonderoga,. Lexington, Hancock, Bon Homme Richard, Oriskany, and Shangri-La.

 

[SSgtC]

Trying to pin down the Essex that got the real deal: the C-11 catapult. They were the SCB-27C plus the usual "outsider" Oriskany, so - 7 of them.
Is that correct ?

Ship​	Decommissioned​
USS Oriskany (CV-34) ​	September 1976​
USS Hancock (CV-19) ​	January 1976​
USS Intrepid (CV-11) ​	Mar 1974​
USS Ticonderoga (CV-14) ​	September 1973​
USS Shangri-La (CV-38) ​	July 1971​
USS Lexington (CV-16) ​	November 1991​
USS Bon Homme Richard (CV-31) ​	2 July 1971​

Seven received the SCB-27C upgrades: Intrepid, Ticonderoga,. Lexington, Hancock, Bon Homme Richard, Oriskany, and Shangri-La.

AFAIK. Lake Champlaign was also supposed to get the same SCB-125A refit that Oriskany got. But it was canceled due to budget cuts.

 

[PFJN]

Hi,
I only just saw this thread and it does suggstssome interesting possibilities. But, as some posters have hinted at, even if an internal combustion catapult were to theoretically give you the potential to launch a larger and heavier plane than you might otherwise have been able to (such as Phantoms off a CATOBAR version of HMS Hermes) there are other issues (byond just launching the aircraft) that would have to be considered before a smallr carrier would truly be able to operate faster and heavier aircraft.

Two issues that immediately come to mind are both "flight deck strength" and "arrestor gear capabilities". Specifically, for example if the intent were to be able to launch a plane like the Phantom (loaded up with a certain war load) from a ship like HMS Hermes then the ship should really havethe capability to also retrieve such a plane at more or less the same war load, so that it wouldn't be necessary to have to dump any exoensive ordnance or large quantities of fuel to safely retrieve the plane in the event that it needs to be immediately recovered shortly after launch.

As such, in the example above, its not fully clear that the flight deck of a ship such as HMS Hermes, which would otherwise by operating lighter and/or perhaps less high performance aircraft than a Phantom would be able to handle the landing impacts/loads associated with the Phantom without additional modifications/strengthening.

And for the second issue noted above, just from a quick look at a Shipbucket overhead image of both HMS Ark Royal (which was converted to be capabl of operating Phantom aircraft) and that of HMS Hermes, when configured in her CATOBAR configuration appears to show a longer angled deck on HMS Ark Royal, with a longer "pull-out distance" for thearrestor cables, than the angled decl length on HMS Hermes. As such, its not fully clear that a ship like HMS Hermes would have enough angled deck space to accommodate an arrestor gear system with a suitable "pull out distance" to safely retrieve a Phanton type aircraft even if newer internal combustion style catapults were fittedwith the capability to launch such an aircraft.

 

[Pioneer]

A catapult with what looks like the hulk of a F/A-18A/C, consisting of four centrifugal turbojet engines as it's power source...

Anyone got any further details please?

Regards
Pioneer

 

[Yellow Palace]

A catapult with what looks like the hulk of a F/A-18A/C, consisting of four centrifugal turbojet engines as it's power source...

Anyone got any further details please?

Not a catapult, but a jet propelled sled for testing arrester gear at Lakehurst Naval Air Center.

Here's another photo, this one with what looks like an A-3 on one of the tracks:

You can see the tracks on Google Earth: https://maps.app.goo.gl/DPUMLrHpdKhpvcJKA

 

[Pioneer]

Not a catapult, but a jet propelled sled for testing arrester gear at Lakehurst Naval Air Center.

Here's another photo, this one with what looks like an A-3 on one of the tracks:

You can see the tracks on Google Earth: https://maps.app.goo.gl/DPUMLrHpdKhpvcJKA

Thank you for the clarification Yellow Palace.
I concur with your analogy of it looking like a Douglas A-3.

Regards
Pioneer

 

[GK Dundas]

Small carrier projects become more viable. The issue with steam cats has always been the need to divert steam from propulsion to the cats to launch aircraft. This slows the ship down. In the Essex class, they would drop from 31 knots all the way down to 19 knots during flight operations. The Midway class would drop from 31-32 knots down to 23. Even the Nimitz class loses speed during flight operations (the exact amount is classified, but it's believed to be down into the neighborhood of 25 knots). With an IC cat, the ship can still deliver its full flank speed, giving you a bigger range of conditions that you can launch in.

For American carriers, that was, mostly, an annoyance. Their ships were big enough, fast enough and with powerful enough catapults that it rarely mattered. The Navy still didn't like it, but they could live with it. The big thing it changes for them, is what it means for the Essex and Midway classes. With C14s in place of their C11s, there isn't a plane in the Navy's inventory that they can't launch at their full up weights. Long term, it doesn't mean that much for those two classes though since they were more limited by their hanger height combined with their limited fuel and aviation ordinance storage than they were by their catapults. They'll make launching in hot and humid conditions safer and easier, but they won't really change how the two classes are operated. Beyond giving them some more flexibility in how the Navy views them (think things like being more willing to divert a Phantom or Tomcat or Vigilante to an Essex or Midway if needed, whereas in OTL, that was only done in extremis).

It might mean the Navy invests more in nuclear escorts though. Since now, the carrier won't be slowing down during flight operations. That means more sustained speed will be needed from the various escorts. Instead of a burst to 30+ knots, they're gonna need to keep it up for a couple hours. That's a lot of extra fuel being burned.

For navies with smaller carriers, though? The C14 is a game changer. It could launch heavier aircraft at faster speeds than any British supplied catapult could even dream of. Ships like 25 de Mayo could have reliably launched Etendards and Crusaders (if Argentina had been allowed to buy them). Melbourne could have flown Crusaders and Corsairs instead of payload limited Skyhawks. Hermes could have launched Phantoms with regularity. Foch and Clem could have operated anything the French wanted them to, and then been sold on to other navies to fly aircraft like F/A-18s off of.

Longer term, it strangles the STOVL carrier in the cradle. With no need for steam to operate the catapults, and with the cats themselves being more powerful on a foot-to-foot basis than an equivalent length steam cat, smaller navies like Italy and Canada could operate smaller CATOBAR decks instead of the OTL choice of Harrier Carrier or nothing.

 

[orlovsky]

Hi,
I only just saw this thread and it does suggstssome interesting possibilities. But, as some posters have hinted at, even if an internal combustion catapult were to theoretically give you the potential to launch a larger and heavier plane than you might otherwise have been able to (such as Phantoms off a CATOBAR version of HMS Hermes) there are other issues (byond just launching the aircraft) that would have to be considered before a smallr carrier would truly be able to operate faster and heavier aircraft.

Two issues that immediately come to mind are both "flight deck strength" and "arrestor gear capabilities". Specifically, for example if the intent were to be able to launch a plane like the Phantom (loaded up with a certain war load) from a ship like HMS Hermes then the ship should really havethe capability to also retrieve such a plane at more or less the same war load, so that it wouldn't be necessary to have to dump any exoensive ordnance or large quantities of fuel to safely retrieve the plane in the event that it needs to be immediately recovered shortly after launch.

As such, in the example above, its not fully clear that the flight deck of a ship such as HMS Hermes, which would otherwise by operating lighter and/or perhaps less high performance aircraft than a Phantom would be able to handle the landing impacts/loads associated with the Phantom without additional modifications/strengthening.

And for the second issue noted above, just from a quick look at a Shipbucket overhead image of both HMS Ark Royal (which was converted to be capabl of operating Phantom aircraft) and that of HMS Hermes, when configured in her CATOBAR configuration appears to show a longer angled deck on HMS Ark Royal, with a longer "pull-out distance" for thearrestor cables, than the angled decl length on HMS Hermes. As such, its not fully clear that a ship like HMS Hermes would have enough angled deck space to accommodate an arrestor gear system with a suitable "pull out distance" to safely retrieve a Phanton type aircraft even if newer internal combustion style catapults were fittedwith the capability to launch such an aircraft.

Deck strength limits were supposedly 50k lbs on Eagle and Ark Royal, probably less on Hermes even if phantomized. Catapult and ship speed would impose a limit of about 45k lbs anyway.

HMS Hermes had the 220ft Mk13 arrestor gear. The american Mk7-1 with 230ft might just fit in and it could handle the F-4 @ typical weights as it did on Midway, FDR, Forrestal and Ranger in the 60s. Single engine landings might be hairy.

The RN plan was of course the dax2. Ark Royal had about 360-370 ft after the last wire, Hermes more likely just 300. The question is how well a shortened Mk14/dax2 would have worked; the strengthened 4.8g F-4K airframe left some room, so it might just work out. Again, single engine landings might be hairy.

 

[Pioneer]

......Specifically, for example if the intent were to be able to launch a plane like the Phantom (loaded up with a certain war load) from a ship like HMS Hermes then the ship should really havethe capability to also retrieve such a plane at more or less the same war load, so that it wouldn't be necessary to have to dump any exoensive ordnance or large quantities of fuel to safely retrieve the plane in the event that it needs to be immediately recovered shortly after launch.

An interesting and valid point PFJN.
Out of curiosity, was the likes of the F-4K rated to deck land with it's launch weight of fuel and ordnance, and was it the operational practices of the RN, let alone the USN to recover F-4's with such weights?
I recall reading that one of the poor operational reliability issues of the Aim-7 Sparrow and Aim-9 Sidewinder missiles in USN F-4's in combat during the Vietnam War was the shock endured by the actual Sparrow's and Sidewinder's to continous take off and landings which effected their compontry.....
I also have in my head that the Grumman F-14D [and perhaps the A-6F Intruder II] was the first USN aircraft capable of being recovered with both it's take off fuel and ordnance load....But it's not the first or the last time I've been wrong.

Regards
Pioneer

 

[orlovsky]

The arrest limits are usually far below the catapult limits.
F-4B catapult 54800 lbs, arrest 34000 lbs
F-4J catapult 56000 lbs, arrest 38000 lbs, later 40000 lbs
The F-4K chart I posted above ends at 40k lbs for the same reason.

If you look at the sacs https://www.aahs-online.org/resources/navy_sac.php then the F-14 and A-6 maximum catapult weights are also well above arrest limits.