WesWorld

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I have yet failed to understand your calculations regarding the CV and you´ve not yet answered my question to please explain what kind of calculations you´ve run. Why? You said you´ve run these calculations.

I'll post it tomorrow in the armoured-carriers thread where there is some more space.

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Regarding your stern design - I think it is very far away from the screw design on late 1930er US BBs. One important factor - on your design the screws and rudders are close to the ships center so the forces generated lack the arm to push the ship around. As it is your ship seems to severly lack manoverability

The difference is using 2 shafts instead of 4 and continuing the skegs aft to the stern. The rudders on SoDak where in the inboard prop races so I can't see a problem there. The maneuverability problem amounts from the skegs extending to the stern so the water cannot be deflected to the side enough. Shortening the skegs would remove this problem.

The Voith-Schneider props are probably the wrong thing to use. Really I want thrusters to use in port instead of tugs. So easier to change to a side mounted prop driven by shaft. Small prop only transmitting 500hp or less, maybe hydraulic or electric drive because of the location.

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I´d also like to know how your hull form reacts once one of your long sterns is flooded by a TT hit. How does such a hull form react to pitch and roll effects if there is off center flooding - and only the latter can happen here.

It will be affected more, but you'll still have propulsion and stearing. The trade off is probably worth it.

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Further more, how does this hull form influence the ships speed and necessary power output? I think of wave length, drag etc. What about range (fuel consumption)? How to calculate this hull forms BC?

Its more efficient than normal hullforms but probably getting some cavitation at high speeds (whether this high speed is 30,40 or 50knts I can't say without test tank models)

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I´d also like to point out that the power per shaft is quite high making special screws necessary etc. This was already discussed - or should I say dismissed - but the single reference to the original CAPITANI ROMANI cannot be accepted as the latter is a much later design.

55,000shp per shaft is not much higher than 48000 of Zara, 50000 of Abruzzi. Maybe need 5 blade props because of the higher rotational speed.

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In general I cannot accept - or at least I fail to see why - Italy to develope one feature after another that is well ahead of times like hydro foils, large void schneiders, deck edge lifts, electro subs etc. Neither has Italy the money, the man, the experience or the necessity to develope all these things. Seriously, how long until you introduce guided missles, fusion reactors and laser beams? :o/

Maybe Italian spies are just good at stealing things?
Those things might be earlier than historically, but they are reasonable and they are actually proven to work. There is no great advance needed, e.g. masses of electronics if I was to build PHMs. Italy already has the guided missiles, they were stolen/acquired/bought from GB. The guidance works reasonably well, but getting a good enough payload is problematic.

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Of course you´ve offered single test design, prototypes and the like as an explanation that it was possible or should I say seemed possible? However, you´ve never seriously explained why such features finally failed in the real world or needed another several decades to make it into service. If I´d take your way to handle things I have to tell you that all SAE planes are driven by jet engines. Just because there was a single french engineer who build a plane in 1909 that was able to fly and powered by a very early and very simple jet engine.... Doesn´t make much sense, does it?

Coanda's design is not an actual jet. Proper jet engines cannot exist much sooner than OTL because of the heat-resistant alloys needed for the turbine blades. Then again there are other possibilities, such as those developed by Italy in OTL which don't require this leap and still have good performance. Why things weren't adopted in the real world, competition and big business. Why were Fiat designs used by Italy when there were much superior alternatives - because Fiat had political clout.

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If Italy have got that lot, can Nordmark have hovercraft and catermeran ships. :-)

Well the hovercraft being invented by AH in WWI then promptly being forgotten for many years. Skirt design was the main problem. Catermarans aren't really very hard to produce just that they have limitations and advantages compared to monohulls. The limitations outweighed advantages as volume wasn't really a factor then.

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What was the most advanced naval aircraft in service in 1931? Okay how about 1936? 1941? Check those historicals verses whatever benchmarks one might set. It seems we are roughly 3 years ahead in aviation techology...at least on the racing curcuit.

Its obvious without hindsight that the capabilities of aircraft will massively increase because of the huge leaps of power being available. e.g. in 1924 or so, the Schneider trophy planes were running at about 750-800hp max as cutting edge. In in 1931/32 the Schneider trophy planes are producing around 2500-3100hp and there are engines producing 1800hp in series production. Aircraft will get faster and be able to carry more things. Already we are moving to all-metal aircraft from wood and fabric of 5 years previous. What will be developed in another 5 years? As Italo Balbo said in 1931 "500kph is already passé, in a few years it will be common to all planes" (he's Minister for Aviation btw)

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What do these real planes need in terms of carrier space, deck room, take off space? Are your carriers too small for them and that's why they have catapults? Are they too heavy for your deck? Are they too large for your lifts?

I can either have cats or centreline lifts. Not enough space for both on 220m. Designs for new aircraft in service 1934/35/36 project stall speeds reaching up to 70-80knts. So if steaming into a wing of 5knts at 30knts then another 35-40knts is needed at least. Do the aircraft have that sort of acceleration? (actually yes now i think about it so it shouldn't be a problem)

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That - and water jets powered by gas turbines....

A reasonable size gas turbine, say 20,000shp+ is decades away, but the water-jets are already here - powered by a 9hp petrol engine.

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the water-jets are already here - powered by a 9hp petrol engine.

Wasn't that on some late 19th century British boat? I read something about it but cannot find the page anymore. :-(

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Wasn't that on some late 19th century British boat? I read something about it but cannot find the page anymore. :-(

No idea. The one I was talking about was used by Venar in Venice lagoon during 1931. I've just found out that there were some unspecified problems with it, these were probably ironed out by 1940 when the RMI ordered 2 boats from Venar (high speed submarines iirc)

So will we see some kind of Red-October-catapilar-propulsion-system for submarines soon? ;o)

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So will we see some kind of Red-October-catapilar-propulsion-system for submarines soon? ;o)

Yes, and armed with at least twin 18 inch guns and carrying at least a squadron of airplanes.

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In in 1931/32 the Schneider trophy planes are producing around 2500-3100hp and there are engines producing 1800hp in series production.

I think you're over-estimating the engines of the day: the R-Type engine used to win the 1931 Schneider race was a 2300 hp engine, while the M.72's Fiat engine (which didn't work in time for the race) was rated at 2850. Neither of these were production engines, they were special builds that were only for the racers. Name two production-line aircraft (ie, more than 20 produced) from 1931 that used engines with more than 1,000 hp.

The production-line radials that would grow to over 2,000 hp in WWII were, at this time, more like 800 hp, and most of the production in-lines were closer to 600.

That is most likely due to the fact that producing the best on an assembly line would put a company out of business...mainly because no government would be willing to pay what the engines are worth if produced correctly. Most governments go with the lowest functional bidder to save money unless they have to spend to get what they want. This could be way there are so many mediocre aircraft in the early days of World War II.

It's more likely that the top end engines, like used on the various racers, were VERY specialized, and like the engines used on racing warbirds today, had to be rebuilt after 1 or 2 races. That's not feasible in any real-world usage. Not to mention that you can lose a fair number of pilots and planes when the engine blows because it's over-stressed.

Also, some of those engines simply weren't very feasible: the mentioned Fiat was 11 feet long, that's not going to be easy to fit into most aircraft.

I have to agree with Hooman for the most part, except he seems to put his concerns into words better than I do.

As far as I'm concerned I think Italy has cornered the market on every conceivable tech out there, how realistic is that?

As a player its simply a huge nusance seeing yet another technology being coined by the Italians, particularily when its one you plan on developing....now that Italy has it your simply a copy cat to develope it weither you planed to anyway or not.

I understand we don't have economic or tech rules (both of which I've lobbied for by the way) but there has to be a realistic cutoff point where vast quantity's of technolgy become too expensive in both manpower and money to develope not to mention the amount of forsight being used to push it forward.

One only has to look at both compairably sized nations and more powerfull ones to see the disparity between the amount of technology.....

In a players point of veiw I'd like to see more players have an opertunity to develope technology without having to look like copycats.

I throw around the occasional Avro Arrow picture as a joke here and there, but I'm wondering how long it'll actually be a joke at this rate. :\

A note regarding airplane piston engines:

Today the most powerful piston engines used for the Reno Air Races in the Unlimited Gold Class have a power of 3,800hp (Merlin and Griffon clones) to 4,000hp (radial engines). To achieve these powers turbos, special metal alloys, highly precise tools etc. are used - most of which were not available even a few years ago.

The max. life span of such an extremly supercharged and powerful engine is 8 to 10 MINUTES ! That´s barely enough for a single race but still many engines wreck before they live long enough to the the flag at the races end.

[EDIT] I´ll comment on the ship stuff later as I´m far from being pleased with the answers given so far. :o/

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So will we see some kind of Red-October-catapilar-propulsion-system for submarines soon? ;o)

Thats what was planned. I don't know why as a pump-jet is less efficient than a normal prop and the decrease in acoustic signature isn't worth it because of the state of sonar.

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Name two production-line aircraft (ie, more than 20 produced) from 1931 that used engines with more than 1,000 hp.

Savoia-Marchetti S.55 and Cant Z.501(well almost 1931), Fiat BR series using Isotta-Fraschini Asso 1000 and Fiat 25 engines respectively.

Both are massive engines, the Fiat 25 weighing over 1000kg and the I-F weighing ~800kg. The Asso 1000 could be substituted for (and was) the Asso 750 (57L vs. 47L) on aircraft that were beginning to be underpowered. The Asso 1000 is running at 1000hp in its de-rated marine form without supercharging or special carbs. The aircraft version is running at 1800hp continuous in 1931. Even so, its still only 31hp/L below Merlin standard in mid 30s.

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As far as I'm concerned I think Italy has cornered the market on every conceivable tech out there

Hardly. I'm fairly amazed when doing research that Italy seems to have a finger in every pie. Most of the developments are based on OTL events. Well the electro subs just wouldn't work on reflection and having new information on battery capacity, but SS says otherwise.

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One only has to look at both compairably sized nations and more powerfull ones to see the disparity between the amount of technology.....

As an example, lets look at the development of radar. In GB and US thousands £s and hundreds of people were involved in its development. In Italy it was developed by one man, in a shed, in his spare time and by 40/41 he had a set that was comparable to GB and the US.

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In a players point of veiw I'd like to see more players have an opertunity to develope technology without having to look like copycats.

Go find something then.

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Originally posted by Red Admiral

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In a players point of veiw I'd like to see more players have an opertunity to develope technology without having to look like copycats.

Go find something then.

Hardly possible playing a fictious country.

Anyway, more later...

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Today the most powerful piston engines used for the Reno Air Races in the Unlimited Gold Class have a power of 3,800hp (Merlin and Griffon clones) to 4,000hp (radial engines). To achieve these powers turbos, special metal alloys, highly precise tools etc. are used - most of which were not available even a few years ago.

Thats because they're getting all that power from an extremely small displacement. 28L for the Merlin and 37L for the Griffon. So they're running at about 100hp/L. If you want an equally powerful engine, go for a more sustainable 30-40hp/L and simply make the engine larger.

R-4360 produced 3000-4300hp from 71.4L, this is 40-50hp/L. They simply made the engine larger (and heavier) than doing anything special.

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savoia-Marchetti S.55 and Cant Z.501(well almost 1931), Fiat BR series using Isotta-Fraschini Asso 1000 and Fiat 25 engines respectively.

The S.55 more usually flew with the 940 hp Isotta-Fraschini Asso 750, and the Cant Z.501 wouldn't fly, in prototype form, until 1934, and was fitted with a 900 hp engine.

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R-4360 produced 3000-4300hp from 71.4L, this is 40-50hp/L. They simply made the engine larger (and heavier) than doing anything special.

Heh, but that's also a post WWII engine.

You´re right - the radials take their power from their size while the smaller Merlins/Griffons use higher supercharger loads and a more streamlined airframe to achieve similar speeds (in the end).

The current champion (a Grumman Bearcat called Rare Bear , winner 2004 and 2005) gets power in excess of 4,000hp out of a R-3350.

However, it is not correct to say "simply make it larger" as this is actually not the case. Very special engine tunning was necessary to achieve this power output. There was a long article about this kind of engine tunning in a magazin called "Flugzeug Classic" which is available in Germany and focuses on old warbirds and liners. Can´t say which issue as I´m away from home but engine size alone won´t win a single race.

End of story: Heavily modified engines with great power output cannot be used to transfer their technology into a mass produced power unit.

btw, I´d like to know where you get the information about italian engines from. One really wonders why Italy had so much trouble producing powerful engines in WW2 when they were ranked top of the list in the early 30s. Later they had to use more powerful german engines after all. As far as I know the British were top of the list when it came to engine technology/power in the 1930s. That´s why most german designs of that era used british engines in first place until german designs became available....

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However, it is not correct to say "simply make it larger" as this is actually not the case. Very special engine tunning was necessary to achieve this power output. There was a long article about this kind of engine tunning in a magazin called "Flugzeug Classic" which is available in Germany and focuses on old warbirds and liners. Can´t say which issue as I´m away from home but engine size alone won´t win a single race.

There was also an article in Air & Space here in the US some years ago on the guys who build/rebuild the engines for those racers. The tuning is very interesting, but it's NOT useful for regular use, because you have to rebuild the engine after only 1 or 2 races because you're stressing the engine WAY, WAY beyond what it was designed for.

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btw, I´d like to know where you get the information about italian engines from. One really wonders why Italy had so much trouble producing powerful engines in WW2 when they were ranked top of the list in the early 30s. Later they had to use more powerful german engines after all.

Aerofan magazine (the bible for Italian aircraft), Ali D'Italia and an aviation enthuisiast who lives near Vinga de Valle musuem.

The problem was that the engines weren't made by Fiat, the Isotta-Fraschini company became obsessed with air-cooled inlines (Delta and Zeta), having only 87-oct fuel, lack of more exotic elements, rubbers and alloys because of imposed sanctions. And the Regia Aeronautica fixation on radial engines. As a result the RA flying boats and MAS had more powerful and more reliable engines than the newer fighters. Interesting comparison is the Isotta-Fraschini L121 developed from the Asso 750. It was around the same dimensions as the Merlin, weighed 100kg less and had similar power. 960hp vs. 1000hp. It was only when 100-oct and 150-oct fuel became available for GB (not available to Italy because of sanctions) that the Merlin began to produce more power, up to 2050hp continuous with the 100+series, or the maximum 2450hp from an engine modified in Derby in 1944.

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End of story: Heavily modified engines with great power output cannot be used to transfer their technology into a mass produced power unit.

Its like using an F1 engine to drive a tank. However the Rolls-Royce Griffon was developed from the "R" racing engine and produced similar power when developed. The Griffon 1 was actually a modified "R"...so it is possible. The length of the 3100hp (2500hp cont.) AS.6 does somewhat preclude its use in fighters.

A version closer to the Aquila class. Differences being the enclosed bow and armament. Two hangars, open unarmoured upper and closed armoured lower hangar. At least now I don't have to park planes on deck.