• Hi Guest! Forum rules have been updated. All users please read here.

Launched directly from hangar

archipeppe

ACCESS: Top Secret
Joined
Oct 18, 2007
Messages
1,802
Reaction score
592
In the very first years of aircraft carriers development both English and Japanese envisioned launch of their aircrafts directly from the hangar. This result was usually achieved through an opening in the bow, at the hangar level, and a catapult that launched aircraft in the ship's direction, like the deck ones one floor above.

Interestingly, during WWII U.S. Navy needed so badly more catapults that they thought to place them even on the ship's side, launching directly the aircraft fighters and recce from the hangar.

In this optic, even if generally less knows, the first 6 Essex class ships were equipped with side catapults (they should be USS Essex, USS Yorktown, USS Intrepid, USS Hornet, USS Franklin, USS Lexington).

1612292838013.png

Trials happened during 1944 involving aircraft like F6F and TBF-1, obviously the catapults itself was shorter than the ones present on the flight deck, furthermore they didn't launched in the ship motion direction, with general poor performances (let's imagine the pilot's joy....).

1612293079512.png
A F6F-3 Hellcat ready to be launched by the USS Hornet (CV-12).

1612293129981.png
A Grumman F6F-3 Hellcat of VF-15, launched by USS Hornet (CV-12) on 12 February 1944 when the ships was located in Chesapeake Bay.

1612293251979.png
The same aircraft as above during its side launch.

1612293333527.png
A Grumman TBF-1 Avenger of VT-5 launched by the USS Yorktown (CV-10).

Even if the concept itself proven feaseble, at the end of 1944 trials the whole thing was judged too complex or at least unsatisfactory and it was abandoned.
By the end of 1944 all the side catapults on the Essex class aircraft carriers were removed.
 

EwenS

ACCESS: Confidential
Joined
Feb 20, 2010
Messages
192
Reaction score
291
Some additional info on the cross deck catapult in the USN.

The cross deck catapult on the hangar deck goes back to the early 1930s and the design of the USS Ranger CV-4, albeit that they were never fitted to her as an economy measure. Subsequently Yorktown CV-5, Enterprise CV-6 & Hornet CV-8 each received a hangar deck H-2 model catapult as well as two of the same model on the flight deck. Wasp CV-7 received 2 such hangar catapults as well as 2 on the flight deck. At that time catapults were little used as aircraft were relatively light weight but even less use was made of those on the hangar deck (Enterprise used hers 3 times in 1941 out of 21 catapult launches total). On 17 Feb 1942 their removal was authorised, and by June 1942 that had been done on Enterprise and Hornet. Yorktown retained hers when sunk. I don’t know about Wasp, but she did receive a short refit in May/June1942 before departing for the Pacific so their removal is possible.

The Essex class were designed in 1939/40 with an H4A cat on the flight deck and an H4B on the hangar deck. Equipment shortages saw Essex complete with none. She received a flight deck catapult only before deploying to the Pacific in mid-1943. Lexington CV-16 also only got the flight deck cat at completion.

The 6 that received the hangar deck catapult were Yorktown CV-10, Intrepid CV-11, Hornet CV-12, Franklin CV-13, Bunker Hill CV-17 and Wasp CV-18. As these ships came in for refits and damage repairs in 1944/45 the hangar deck catapults were removed and a second cat installed on the flight deck, so bringing them into line with later completions.

Those Essex class completing from the beginning of 1944 had the hangar deck cat replaced with a second flight deck cat.

As aircraft weights increased the hangar deck cats were found to be of less and less use since there was no additional benefit from the wind over the deck generated by the ship’s speed through the water to aid the launch. Hornet CV-12 was the last to lose her hangar deck cat in her Jun-Sept 1945 refit.

In the pre-war British (Furious, Courageous and Glorious) and the Japanese Akagi and Kaga) there were no catapults at hangar deck level to assist aircraft in taking off. All takeoffs from the hangar deck level in these ships were unassisted. As aircraft grew in size and weight this became impossible. So the Japanese rebuilt their ships to eliminate the feature in the mid1930s.

In C&G the lower flight deck wasn’t used after 1935 and the doors welded shut. Furious’s forward hangar opening was plated in as part of her 1938/39 refit.

Incidentally no Japanese Carrier was equipped with a catapult.

Catapults only reached RN carriers with the completion of the conversion of Courageous in 1928. Of the earlier carriers only Argus ever received one before being either sunk or retired.
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
No Japanese carrier equipped with catapult remained with such catapults equipped. At least Kaga but maybe Akagi as well were equipped experimental catapults but these were removed when they were modernized.
 

GTX

All hail the God of Frustration!!!
Senior Member
Joined
Apr 15, 2006
Messages
3,177
Reaction score
864
Website
beyondthesprues.com
Another view showing one of the catapults:

message-editor%2F1498582433845-f6f-3_vf-1_on_uss_yorktown_cv-10_1943.jpg


Source
 

EwenS

ACCESS: Confidential
Joined
Feb 20, 2010
Messages
192
Reaction score
291
No Japanese carrier equipped with catapult remained with such catapults equipped. At least Kaga but maybe Akagi as well were equipped experimental catapults but these were removed when they were modernized.
Are you sure about this? I’ curious, do you have a source?

The Warship articles I have by Hans Lengerer published back in the 1980s make no mention of this installation on either ship.

Over at Combined Fleet, usually one of the more reliable sources when it comes to Japanese warships, the comment is that while the catapult seatings were installed in Kaga in a May-Nov 1940 refit, it is not clear whether the 3 air-propelled catapults themselves were installed or not.
 

DWG

ACCESS: Top Secret
Joined
Feb 11, 2007
Messages
862
Reaction score
643
An unmentioned issue so far is hangar deck catapults mean you need to keep a whole section of the hangar out of use for the other things supposed to be happening in the hangar. Remove that usage and it frees up a fairly significant area of space for aircraft storage/maintenance/warming up. It's possibly a smaller issue for the forward launching designs as they needed very short take off runs and could use the unenclosed bow for that - ISTR the RN spent a significant period only using hangar deck launch for the lightweight Flycatchers, not for the heavier strike and reconnaissance aircraft.
 

Jemiba

ACCESS: Above Top Secret
Staff member
Top Contributor
Senior Member
Joined
Mar 11, 2006
Messages
8,283
Reaction score
1,207
, obviously the catapults itself was shorter than the ones present on the flight deck, furthermore they didn't launched in the ship motion direction, with general poor performances (let's imagine the pilot's joy....).
The Hellcat, not to mention the Avenger, are a different class of aircraft, compared to the Supermarine Walrus, being
about half the weight. But, not to forget, about double the installed power, too.
And the Walrus was launched from a number of RN ships (King George-V class BB, County class CA), from a catapult
maybe not that different to the US type, in exactly the same direction, as a standard type of use.
(Photo via reddit, https://www.reddit.com/r/Warthunder/comments/230bxr View: https://www.reddit.com/r/Warthunder/comments/230bxr/a_supermarine_walrus_amphibian_airplane_being/
)
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
No Japanese carrier equipped with catapult remained with such catapults equipped. At least Kaga but maybe Akagi as well were equipped experimental catapults but these were removed when they were modernized.
Are you sure about this? I’ curious, do you have a source?

The Warship articles I have by Hans Lengerer published back in the 1980s make no mention of this installation on either ship.

Over at Combined Fleet, usually one of the more reliable sources when it comes to Japanese warships, the comment is that while the catapult seatings were installed in Kaga in a May-Nov 1940 refit, it is not clear whether the 3 air-propelled catapults themselves were installed or not.

For Kaga here:


and
o1858046414714876196.jpg

soryu0806.jpg

https://pbs.twimg.com/media/CTvA3UiUwAAenqb?format=jpg&name=large
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
Only Kaga received Catapults as the images shows, Akagi did not but I suspect it was considered as well.
When Oyodo was still in the hybrid phase of Cruiser-Carrier design it featured catapults (likely the widely used gunpowder type)
v2-f8912c308aa189ab12a85568ac9b8176_720w.jpg

v2-7e13be40601992b721051ab0b8e1c56b_720w.jpg

(Images are from Japanese carrier oriented magazines)

I wonder what was the technical difficulties of developing a Hydraulic catapult similar to what the RN and USN used but the IJN were not figured out?
 

Brickmuppet

ACCESS: Confidential
Joined
Nov 11, 2006
Messages
186
Reaction score
26
Website
brickmuppet.mee.nu
When Oyodo was still in the hybrid phase of Cruiser-Carrier design
Whut?

Oyodo was at one point conceived as flight deck cruiser?
Given the Japanese preliminaries for the Shokaku and the role of the Oyodo this makes sense, but I'd never heard anything about it. (Not that I have ever paid much attention to the Oyodo) Do you have any citations or stats on the ship in that design phase? 8000 tons is awfully small for a carrier landing.
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
Oyodo started it's life in 1938 as a small cruiser of 5.000tons with 4x2 12,7cm Type 89 this enlarged to 6.600tons but armament unchanged and possibly reflecting the change as the E16A Paul grew in size (Both designed to carry 6 floatplanes)
By late 1938 Oyodo grew to it's almost final size: 8.200tons 2x3 155mm 4x2 10cm still 6x floatplanes
The Cruiser-Carrier design was W-105 which looks like had the same hull size as the Oyodo but displacement doubled to 16.600tons (Had to re-check my sources) and 20 aircrafts
 

EwenS

ACCESS: Confidential
Joined
Feb 20, 2010
Messages
192
Reaction score
291
, obviously the catapults itself was shorter than the ones present on the flight deck, furthermore they didn't launched in the ship motion direction, with general poor performances (let's imagine the pilot's joy....).
The Hellcat, not to mention the Avenger, are a different class of aircraft, compared to the Supermarine Walrus, being
about half the weight. But, not to forget, about double the installed power, too.
And the Walrus was launched from a number of RN ships (King George-V class BB, County class CA), from a catapult
maybe not that different to the US type, in exactly the same direction, as a standard type of use.
(Photo via reddit, https://www.reddit.com/r/Warthunder/comments/230bxr View: https://www.reddit.com/r/Warthunder/comments/230bxr/a_supermarine_walrus_amphibian_airplane_being/
)
The catapults on the flight deck and hangar deck, although different model numbers, are of the same length, or almost so. The hangar deck cat had extensions at both ends that folded upwards when not in use, which brings its overall length up to that of the flight deck cat.

As for the respective aircraft weights I’m not following you. Maybe something has been lost in translation.

Walrus - empty 4,900lbs gross 7,200lb max t/o 8,050.
Hellcat - empty 9,414lb, loaded 12,647lb
Avenger - empty 10,843lb loaded 18,250lb

So both the Avenger and Hellcat are heavier empty than a Walrus at max take off weight.
 

archipeppe

ACCESS: Top Secret
Joined
Oct 18, 2007
Messages
1,802
Reaction score
592
In any case even German and Italian battleships and battlecruisers had catapults for their Arado Ar-96 or IMAM Ro-43 and Reggiane Re 2000.
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
When Oyodo was still in the hybrid phase of Cruiser-Carrier design
Whut?

Oyodo was at one point conceived as flight deck cruiser?
Given the Japanese preliminaries for the Shokaku and the role of the Oyodo this makes sense, but I'd never heard anything about it. (Not that I have ever paid much attention to the Oyodo) Do you have any citations or stats on the ship in that design phase? 8000 tons is awfully small for a carrier landing.
I was correct with the displacement.
Here is the page from Eric Lacroix's book:

1612453132711.png
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
Regarding the matter of laucnh from hanger, the British proposed such carriers in the 1950's and 60's where there were catapults leading from the Hanger on an angled ramp, will post the drawings later when I find them.
 

Dilandu

I'm dissatisfied, which means, I exist.
Joined
May 30, 2013
Messages
1,181
Reaction score
672
Website
fonzeppelin.livejournal.com
A question; where there any attempts to put rotating catapult on carrier? So it could be used to launch planes in any wind direction?
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
I know no such realised ideas but again the same carrier I've mentioned for the RN a different one featured something like that
But remember rotating catapults are required for surface ships to launch the aircrafts out from the shadows and nuisance of the hull structures. The carreir is basically a floating airfield, plenty of space to take off of.
 

Dilandu

I'm dissatisfied, which means, I exist.
Joined
May 30, 2013
Messages
1,181
Reaction score
672
Website
fonzeppelin.livejournal.com
I know no such realised ideas but again the same carrier I've mentioned for the RN a different one featured something like that
But remember rotating catapults are required for surface ships to launch the aircrafts out from the shadows and nuisance of the hull structures. The carreir is basically a floating airfield, plenty of space to take off of.

Hm, I always though that main advantage of rotating catapult was the ability to launch into wind regardless of the ship's own heading.
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
yes but while a carrier could turn into wind easily and it does not matter if it's in a pursuit or actively searching as it has long striking range via the aircraft for a cruiser or battleship that would make a possible pursuit or search less efficient as sometimes the wind blows from the aft of the ship and making a full 180 degree turn just to launch an aircraft is not too optimal (if you lack rotating catapults). In case of the British that is compensated by the longer catapult length as they were usuall full cross deck length.
 

Tzoli

ACCESS: Top Secret
Senior Member
Joined
Feb 1, 2011
Messages
1,561
Reaction score
847
Here is the HMS Warrior envisioned with catapults.
And the two Hanger Catapult launch carrier design of the RN
 

Attachments

  • 20210205_203528.jpg
    20210205_203528.jpg
    686 KB · Views: 35
  • 20210205_203613.jpg
    20210205_203613.jpg
    848.4 KB · Views: 37
  • 20210205_203641.jpg
    20210205_203641.jpg
    810.1 KB · Views: 37

Similar threads

Top