Endurance of RN ships

[phil gollin]

I don't know who you mean, I have merely posted the information from the RN reports. If you wish to listen from someone who doesn't have first-hand information, I can't help you.

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[Foeth]

Anyway, let's put this bickering to rest. For your information, I work at on of the foremost research facilities as a propeller designer and propulsion hydrodynamic researcher. So, when I say I have some doubts about the conclusions of that research, it's not total guesswork. I still don't see how one connects tuft tests to skew, and still doubt that this is what tempted people to apply it to propeller design.

[Werner]

Anyway, let's put this bickering to rest. For your information, I work at on of the foremost research facilities as a propeller designer and propulsion hydrodynamic researcher. So, when I say I have some doubts about the conclusions of that research, it's not total guesswork. I still don't see how one connects tuft tests to skew, and still doubt that this is what tempted people to apply it to propeller design.

Didn't do the propellers for Charles de Gaulle, did you?

[Foeth]

Oh no, fortunately not

[phil gollin]

Anyway, let's put this bickering to rest. For your information, I work at on of the foremost research facilities as a propeller designer and propulsion hydrodynamic researcher. So, when I say I have some doubts about the conclusions of that research, it's not total guesswork. I still don't see how one connects tuft tests to skew, and still doubt that this is what tempted people to apply it to propeller design.

I think you need to look up the original reports - all nicely available at the TNA:PRO (and also the RN Scientifi Journal). The reports state that that is why they they went to skew propeller designs - why do you think they lied ?

Good luck to finding it in open printed sources - as most of this was covered by the official secrets acts at the time - how many published sources do you know for the development of the Agouti system ?

[chuck]

I tend to think an outside expert's opinion that a certain version of events is very unlikely can afford more insight into the nature of the underlying mechanics than the fact that events did in fact, for once, occur in the manner described.

[Werner]

Looking aside from propellers for a moment, many USN warships were designed and commissioned with "cruising turbines", which is a separate stage in the turbine system. When they were in use, low and medium speeds could be attained with great efficiency. Before 1910 or so, the USN decided a range of 10,000 miles and a cruising speed of 10 knots were necessary for their mission of traveling as a fleet from San Pedro (Los Angeles) to Manila and arriving able for combat.

With it's vast system of bases and alliances, the RN could afford smaller, shorter range ships. From a strategic standpoint, the British ships were not designed to steam halfway around the world for a major fleet engagement, but rather to protect certain trade routes against cruisers and armed merchant cruisers. As a result, their ships were designed to be most efficient at 19 knots, rather than the 10-15 knots of American ships.

None of this relates to the maximum speed, since no fleet commander would expect more than a few days at top speed; the amount of maximum power fit to a ship to achieve the maximum speed is a strategic decision taken at other levels, and it only effects the amount of machinery crammed into a particular hull. Very little of the design for cruising or optimal speed can be tailored to also benefit top speed.

In addition, there is the ability to accelerate. The USN Adams class destroyers were admired by many navies for their ability to accelerate from cruise to maximum speed without 'breaking a sweat', while more powerful ships nearly required an 'act of God' to get rapidly to top speed.

The Italian Navy of the 1930s and to a degree the French Mediterranean Fleets had different needs. They had very short distances to travel, and so could disregard the need for endurance and damage control, since they were usually only a few hours from a major yard.

[Foeth]

I think you need to look up the original reports - all nicely available at the TNA:PRO (and also the RN Scientifi Journal). The reports state that that is why they they went to skew propeller designs - why do you think they lied ?

I can only find a theorerical investigation from 1951 (searching for propeller and skew), so that's not helpful. So if you have the report, put in online somewhere so that we can see it. I cannot find any reference to this test, tests with tufts on propellers, or anything similar that would lead to skewed propellers. And that includes a few very old publications and general propeller books. So, unless you have something more concrete than late-afternoon anecdotes, I still don't believe you.

[phil gollin]

I think you need to look up the original reports - all nicely available at the TNA:PRO (and also the RN Scientifi Journal). The reports state that that is why they they went to skew propeller designs - why do you think they lied ?

I can only find a theorerical investigation from 1951 (searching for propeller and skew), so that's not helpful. So if you have the report, put in online somewhere so that we can see it. I cannot find any reference to this test, tests with tufts on propellers, or anything similar that would lead to skewed propellers. And that includes a few very old publications and general propeller books. So, unless you have something more concrete than late-afternoon anecdotes, I still don't believe you.

You really are being quite silly.

You seem to think that because you can't find something printed it doesn't exist - you obviously have not tried researching stuff that was originally classified as confidential - I also note you avoided the equivalent problem of the Agouti system (which again is something which you "should" know about if you are claiming knowledge of the development of propellers.

Try actually thinking before calling people liars - it might possibly help.

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[Foeth]

You came up with some story, so if you want the benefit of the doubt you should at least be able to cough up the facts. So far you haven't. You only mentioned aquatic sheep and a general pointer to the archives. And so far I only expressed doubt and haven't called anyone a liar (you made that up), I even asked you for your material on the subject. But that material is apparently classified. I think I'll use one of the forum's new features and put you on my ignore list. What little you say is now replaced by actually nothing, which is semantic at this point.

[phil gollin]

You really do need to re-read your own posts (oh, and mine).

I see you still haven't come up with anything on the Agouti system - I wonder why. The whole history of the subject is fascinating and very long with various twists and turns).

Your main problem is that you are using 1990s/2000s thinking for 1940s experiments and facilities - you need to go back to the actual documents to see what was done, NOT think that the way you do things was the way things were done - a bit of thought and research goes a long way.

Again, the material "is" not classified, it "was" classified, again learning to read properly would help.

If you wish to engage your brain before writing anything I will give you a hint. Try the TNA:PRO catalogue search function, put in the terms "ADM" and dates "1939" to "1946" and in three searches "propeller", "noise reduction" and "cavitation" - you should get 168, 5 and 45 "hits" respectively. - Two of those are the ones you want - have fun.

(oh, and try to think about the differences between now and then).

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[chuck]

We are perilously close to calling each other names, and Werner is not even involved.

[kennylibben]

Yes, lets try not to pour any gasoline on this fire.

[Werner]

Yes, lets try not to pour any gasoline on this fire.

Not without the appropriate carbon credits.

[JWintjes]

Yes, lets try not to pour any gasoline on this fire.

Like mentioning Des Moines and Yamato in one and the same sentence?



Jorit

[Timmy C]

Like mentioning Des Moines and Yamato in one and the same sentence?



Jorit

Oh !

/runs