New RSAN designs for 1930

Italian Stallion

Sunday, April 9th 2006, 4:35pm

Quoted

Your joking right?

I'm totally serious. You know I'm an engineering student and I just happen to love 2-stroke diesels because of all their advantages. The problem with the Junkers engines was the arrangement, double-acting with 2 pistons per cylinder. I'm thinking that a Vee arrangement gives me an easier size. 2-stroke diesels need the supercharger in order to compress the air needed for scavenging. The problem is that the supercharger is mechanically driven and robs the engine of useful power. The idea is to use an engine driven supercharger for startup before switching to exhaust driven turbosupercharger which does not take up power from the engine. Another problem is that at high altitudes you actually want the exhaust gases to provide you with more thrust. Can't do that with a turbocharger.

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thesmilingassassin

The Chosen One

Posts: 13,513

22

Sunday, April 9th 2006, 10:02pm

Can you point out any WW2 era planes that used diesels, experimental or otherwise?

Sounds overly complex for the time era we are talking about.

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AdmKuznetsov

Sage

Posts: 2,918

23

Sunday, April 9th 2006, 10:37pm

Diesel aircraft

Quoted

Can you point out any WW2 era planes that used diesels, experimental or otherwise?

Soviet Pe-8 4-engined bombers used them, and 18 of them bombed Berlin in the days after Operation Barbarossa started. There were several engine failures on the mission, so they were replaced by engines burning avgas. I don't know the technical details of the engine failures, so they might not apply to RA's idea.

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Red Admiral

Italian Stallion

Posts: 7,019

24

Sunday, April 9th 2006, 11:13pm

Junkers 86 in mid 1930s using Jumo 205 engines as mentioned earlier. Various other German aircraft designed by Junkers company.

Quoted

Sounds overly complex for the time era we are talking about.

2-stroke diesels are quite simple mechanically, have a low weight and good fuel economy. They are commonly used in large ships today. http://www.wartsila.com The largest motor they offer is the 33400L 14 cylinder monster that produces 80,000kw. They are also good for smaller-scale applications.

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Marek Gutkowski

Professional

Posts: 1,280

25

Monday, April 10th 2006, 12:37am

I had a 2-stroke car(not diesel) and I know how good those engines are.
I also once were inside a naval 2-stroke diesel piston,it wasnt working at that time,it was in gdansk politechik machinery department the piston was one meter wide and 1,5 meter tall the engine had 6 six of them.

As for Diesels in WWII aircrafts,one Me-109 variant had one cant remember with C or D.

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Hrolf Hakonson

Scooby-Doo

Posts: 6,178

26

Monday, April 10th 2006, 12:48am

Lots of pre-war German aircraft had diesels, but it was found during the Spanish Civil War that they had some drawbacks for combat aircraft, the main one being that they didn't like sudden changes is throttle setting and if the throttle was changed too fast they'd stop. Rather disconcerting for the pilots.

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thesmilingassassin

The Chosen One

Posts: 13,513

27

Monday, April 10th 2006, 1:00am

I meant difficult from the standpoint of eliminating the complications of adapting diesels for aircraft such as the turbocharger and rapid throttle change issues.

It seems more practical to stick with the more reliable avgas/petrol engines.

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Red Admiral

Italian Stallion

Posts: 7,019

28

Monday, April 10th 2006, 11:32am

Quoted

I meant difficult from the standpoint of eliminating the complications of adapting diesels for aircraft such as the turbocharger and rapid throttle change issues.

It'll be worked out over the 1930s which is why it's better to start early.

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HoOmAn

Keeper of the Sacred Block Coefficient

Posts: 7,417

29

Monday, April 10th 2006, 1:53pm

Away from plane engines and back to the original topic...

Somebody mentioned the CV30 design would be too small for 70 planes and avgas would be a problem.

Now, at the weekend I had the chance to check my books and after comparing my design to Ryujo, Soryu, Ranger and Wasp (i compared CV30 to purpose build carriers of similar size only) I doubt I was too far off the mark.

1.) RYUJO had 2/3 the size and 2/3 the airwing of my CV30 design. She was known to be cramped.

2.) SORYU was about 2000ts larger, featured similar armament and a 70-plane airwing (of WW2 sized planes9 but had a powerplant much larger and more powerful than my CV30.

3.) RANGER was about the size of CV30 with a similar airwing, speed and armament. She was also known to be a little it cramped.

4.) WASP was about 1000ts larger but had an airwing including additional 15 planes and was better protected and armed.

None of the above were known to lack enogh avgas according to my sources.

So I think CV30 is absolutely within a reasonable technical frame. Once planes get larger she might become a little bit cramped and her airwing reduced (as already stated) but right now she seems a pretty good and reasonable investment.

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Ithekro

Sage

Posts: 3,661

30

Monday, April 10th 2006, 4:44pm

A drawing might help. One from Hooman and one from those that think she is too small. That way we can see why this disgreement is happening.

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HoOmAn

Keeper of the Sacred Block Coefficient

Posts: 7,417

31

Monday, April 10th 2006, 4:55pm

I don´t think this is necessary. CV30 is quite similar in size (dimensions) to WASP - and on the american carrier they put 85 planes.

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Red Admiral

Italian Stallion

Posts: 7,019

32

Monday, April 10th 2006, 6:02pm

RSAN Anvil probably can fit 70 planes onboard, but only with a deckpark. Single hangar deck is a must because of the lack of beam which leaves 40-50aircraft parked on deck and exposed to the elements.

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alt_naval

Professional

Posts: 1,375

33

Tuesday, April 11th 2006, 1:32am

I agree with Ithekro. A drawing will help. Your recent criticisms of my BB design prompted a comparison of Memnon where I found the sim was South Dakota and the drawing was Littorio.

A 15,000 ton ship is borderline on one or two hangar decks which makes a big difference in stability. As RA points out - Wasp employed a deck park.

Cheers,

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HoOmAn

Keeper of the Sacred Block Coefficient

Posts: 7,417

34

Tuesday, April 11th 2006, 10:05am

I doubt a single hangar deck is a must on a ship of 14kts, 23m beam and 215m length. Don´t forget this is a purpose build ship like the japansese SORYU - a ship with a much higher length to beam ratio which should be an indicator for stability issues.

When I look at RANGER - another two-decker according to my informations - she hadn´t any stability issues, too. And her hull, speed and airwing is very similar to CV30.

WASP was more clumpsy with a shorter but beamier hull but stability problems I know none even though she also had a heavier (larger) superstructure.

So I agree, a drawing might help. But I still think 70 planes is okay for her. At least in the early to mid 30s. After that h angar height or deck space become more of a problem - unless the RSAN introduces deck parks.

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thesmilingassassin

The Chosen One

Posts: 13,513

35

Tuesday, April 11th 2006, 11:07am

I agree for the most part with Hoo, allthough I still think 70 is a wee bit high, 60/65 seems more likely. When drawing Alioths hanger layout it was tough shoehorning 55 planes into her hangars and shes roughly similar to anvil.

I totally disagree with the single hangar suggestion, Ryujo, a converted liner, had a stacked hangar set up and 48 planes on a 10,000 ton merchant hull. Her beam was even more narrow than Anvils and she was roughly 180 feet shorter.

Both carriers lack any serious protection and at their size it likely wouldn't make a difference if they did pack on some armor anyway. If Alioth can ship 55 with reasonable armor and a CL armament Anvil should be able to ship a few more aircraft.

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alt_naval

Professional

Posts: 1,375

36

Tuesday, April 11th 2006, 12:04pm

I totaly disagree with your statement that Ryujo was a converted liner. There was nothing merchant about her hull.

Cheers,

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1Big Rich

Intermediate

Posts: 180

37

Tuesday, April 11th 2006, 5:07pm

I think Wes is thinking of Hiyo and Junyo, which were converted liners.

Shoho, Zuiho and Ryuho were part of the shadow program, ostensivley started as other types.

Ryujo was a purpose built, though small, carrier. Like Wasp, she was to consume unused treaty tonnage.

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thesmilingassassin

The Chosen One

Posts: 13,513

38

Tuesday, April 11th 2006, 7:51pm

She's still a good compairison either way, essentially the Yubari of Japanese carriers.

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Marek Gutkowski

Professional

Posts: 1,280

39

Wednesday, April 12th 2006, 12:04am

I think that this ship can hold 70+ planes of 30 vantige but when it will enter service its park area will no longer be able to hold that many planes.Shokoku was design to hold 96 planes but when it enterd service it was holding 84 planes are geting bigger.
SpadXIII<Spad 51<PWS A<PZL P11c<Jak 1M<Jak 9P
All those planeswere not only bigger but reqaierd more space of sopport equipment,more people were nead to operate them.
PWS A neaded three men and 5 hours of there work
PZL P11c neadedd six men and 9 hours of there work

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WesWorld

Quoted

Diesel aircraft

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