powerandpassionNazi Germany had no export trade between 1939 and 1945, well, negligible anyway; the Royal Navy very effectively blockaded Germany, as they had in the First World War. The only nations that Germany could trade with, that Germany hadn’t conquered, were Switzerland and Sweden; as for the conquered nations…
…well, Nazi Germany just stole whatever they needed and didn’t pay the labour they enslaved!
I’m not sure the U-Boats ‘held back’ from torpedoing US merchant shipping either; if it was afloat in the Atlantic it was fair game.
As for German sea-trade there were a few merchant-ship blockade-runners and U-Boats attempted to bring essential raw-materials back from the Japanese held Far East.
CD I am with you on the expropriation of assets and enslavement of labour but I figure the game had to be more sophisticated than that. I am reading about the V2 program at the moment and the budget exceeded NASAs for the moon shot. Slave labour was 5%, alcohol for fuel had to be traded with other nations as a product of private enterprise. All of the continent of Europe was in a defacto EU, much as modern ASEAN was within the Japanese Co Prosperity Theatre after 1942. The Australian government was in fact in negotiations to trade aircraft for minerals until 1941; no one has really written anything on economic warfare in WW2, even though it seems to be such a paramount feature of modern strategy, eg Russia and the Ukraine. I still feel uncomfortable seeing a Mercedes tristar on a DB engine, mixing the mink with machine guns. These same undercurrents will be the oatmeal of future conflict, it would be good to understand them in all their detail and subtlety.
powerandpassionCopies
The answer to your questions are given in T.O. No. 03-20CC-4 and Air Publication 2121A & B, Interchangeable Parts List – Hydromatic propellers.
Beaufighter, thank you for information. Do you have copies of the TO & AP that I could pay to get copied? Do you also know if DEHAVILLAND manufactured hydromatic parts are directly interchangeable with US manufactured hydromatic parts? Thank you
powerandpassionSubsidiaries of United States companies would have operated in Germany before World War Two and would have continued to do so once the war had started, often under their original name. For example Ford produced trucks in German factories for the German forces throughout the war.
Commercial relationships worked both ways – the UK affiliate of Germany’s Magnesium Elektron carried on, and apparently there was a gentleman’s agreement that these facilities, in either country, would not be bombed, and they were not. Until December 1941, two years after the start of WW2, the United States and Germany were not at war, so it is entirely feasible that US products would be used in Germany. In the face of Lend Lease arrangements between the UK and USA, involving the supply of a multitude of armaments to the UK, it is a wonder that German U Boats held back from torpedoing US ships, unless a certain percentage also held German trade.
It would be interesting to understand where Nazi Germany earned foreign exchange between 1939 and 1945 – how was the massive cost of the war funded and from what forms of export.
There has always been a cold, pragmatic and subterranean trade between belligerents. What got Hitler’s goat about WW1 was Basil Zaharoff, the armaments trader in effective control of Germany’s Krupps and England’s Vickers, who it was said would have been knighted by whatever side had won.
powerandpassionAdd that to harpooning whales and underpants vending machines. In respect of cars there are registration rules that prohibit 5 year old cars from being on Japanese roads. I wonder if there are similar rules for old aircraft that meant the only option for the bureaucracy was scrapping. Perhaps, given that they are still a viable weapons platform a Harvard is still subject to US ATAR rules and must be buried like Aussie F111s. Perhaps we should write a letter to Japanese Self Defense Agency offering our services for aircraft waste disposal….
powerandpassionTwo wings good, Four wings bad
No worries, thank you for making it available to the forum in the first instance.
Four winged aircraft pictured :
[ATTACH=CONFIG]229176[/ATTACH]
powerandpassionAll had Marstrand self centering tyres, the ones with two ridges around the circumference to assist in managing shimmy in castoring.
powerandpassionGetting into drag
It has been said that Camm selected the ClarkYH profile, with thickness of 19% at the root, for the Hurricane after the RAE had advised that there was no appreciable drag advantage in using thinner profiles, based on research carried out in their new compressed air windtunnel. Can anyone confirm that this RAE report was produced, if it is available or is the story apocryphal?
My tuppence :
In 1935, within the literature, such as Air Annual of the British Empire, Aircraft Engineering etc, there seems to be a live debate between designers on matters that were turning accepted wisdom upside down, eg stressed skin fuselages versus girder construction and monoplanes versus biplanes. I do not think there would be one defining document that represents the Eureka moment implied in the selection of aerofoil for the Hurricane.
One realization that comes out of the literature on various designs is increased drag using a deeper section monoplane aerofoil, but decreased drag in comparison to a biplane with thinner profile, but added overall drag caused by flying wires, struts.
In the context of Hawker thinking, the PV 3 & PV 4 biplanes immediately preceded the dramatic step to a monoplane design. There is a PV4 wing pictured on hawkerhind.com which shows a larger aerofoil in comparison to the Hart family biplanes, which travelled over to the first fabric covered Hurricane wing design. You can almost see the design thinking evolving.
A lot of Clark YH aerofoil work was done by Bristols; the Bulldog biplane had it which caused so much angst to Hawkers when they lost the contract to Bristols for RAF fighter in the late 20’s, no doubt Camm would have studied this competing design intensively and would have known its characteristics, if not the astonishing progress of American designs like the DC-2 which gave British design pause after the 1934 London – Melbourne Air Race.
No doubt Camm would have needed ammunition to go to the Hawker Board to persuade them to back a radical design change. No doubt ‘what was in the air’ at the time in terms of design thought and progress was driving him to reconsider his approach with the PV4. It would be natural that an independent third party verification of this design change was prudent technically and politically, and where better than from the RAE. It is also commonsense that no national government would want to support publishing a paper in 1935 which set out the latest in aeronautical thought to a world starting to rattle its sabres.
These designs were the product of an orchestra : mathemeticians, stressmen, businessmen, scientists etc all bringing something to the party,and the conductor was the chief designer. I doubt if a single document really would have such a profound impact, unless you live in a degraded age where one report on WMDs is enough to go to war over…
powerandpassionHow many of you have spotted the chaps on the wing?
I love the casual, “stretch the legs” part of the photo, a long trip, well done. The blokes paddling out in their dinghy for a lookee. You can see the tree on the bluff showing the direction of the predominant wind, and some sightseers on the bluff looking at this great colossus coming in from a far off place. Maybe, with all the congestion and difficulty in getting to modern airports it’s time to bring back flying boats with their capacity to land near St Mark’s square in Venice or Sydney Harbour opposite the opera house. Maybe we could set up a luxury, modern day service for the well heeled retiree, we just need to flog the flying boat at Motat in NZ…
powerandpassionBob, the third pic of the “throttles” is actually of the Teleflex HP and LP c**k levers as fitted to the likes of Hunter and Meteor.
Anon.
Anon, can you please elucidate on the function of the Teleflex HP and LP levers : I have the same thing with Mosquito 98 part numbers on it but can’t figure out what it was used for in that application.
Just to see whether the keyforum server is a feminist I will write fanny and see what happens !
Sweet Fanny Adams
powerandpassionCombat Wellesley
Was it a bigger engine, or just a Pegasus development (Mk.XVIII?) in a NACA cowling? I don’t believe any saw service. A quick look in The K File doesn’t come up with any Wellesleys in secondary units such as target tugs – apart from normal attrition and ferry losses they were all worked to death in the ME against the Italians. At least one was retained in the UK by the RAE and used on communications duties.
I find the “Mk.II” Wellesleys interesting. These have modified canopies, and seem to be the ones replaced in UK bomber squadrons and refurbished at Vickers before being sent overseas.
Here is a picture from “The Abbysinian Campaigns” released by HM Government in 1942, a very good read.
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I think these were the first geodesic aeroplanes in service ? The Keren campaign was a large battle where the RAF were involved in bombing Fascist Italian mountain positions, by the look of this Wellesley it certainly saw some combat.
powerandpassionPint all around
Actually I think PowerandPassion deserves the honours with figuring-out the magneto timing on the Bristol Jupiter!
Thank ye kindly sir, let’s split the beer in half, as your gentle reminder of Otto cycle principles and original insight into 1.125 drive ratio was the key to thinking through the logic.
Some supplementary questions :
What confused me was the lengths that the designers of the Jupiter went to so they could use as many components as possible from an existing magneto; unless there is some other reason that a magneto must produce four sparks per revolution of the rotor-drive shaft? Why not produce a magneto that produces three sparks per revolution of the rotor-drive shaft?
I thought about this while scribbling on the whiteboard. Here are a sequence of cascading thoughts, joined geodesically…There would be many constraints for the engine designer : geometry and volume within the crankcase to allow ancillary drive gears, ie, would a 1:2 gear even fit (consider that the Kestrel 1:1.5 came via a large number of gears, opening greater possibilities for mis-timing/how much more elegant to fit a single gear drive/where do you put it and how do you make it fit?) Also obviously cost : the Cosmos Jupiter was essentially a private venture by an insolvent company, unnecessary and illogical to develop a dedicated 9 cylinder magneto, why not use what was on the shelf and drive it appropriately, and simply. In fact a standard magneto with a four lobe cam driving the contact breaker points will do a 7-9-10-12-14 cylinder engine without seriously challenging the engine designer with excessive gear ratios. I think the 3 cylinder Bristol Lucifer and 5 cylinder Armstrong Siddeley engines DID use different, smaller magnetos, perhaps for weight reasons only.
In fact, thinking about, in terms of successful British aero-engines of the period, wouldn’t the Jupiter not only come before many (Rolls-Royce Kestrel?) but wouldn’t it also have been built in larger numbers (especially considering licensed production)? So why would the Jupiter be using a magneto designed for something else?
The BTH magnetos were used on V12 RR Eagles in WW1, V8 Wolseley Vipers and Armstrong Siddeley was making 7 cylinder radials in 1920. BTH seemed to be the folk investing in magnetos and no doubt a brilliantine haired salesman was showing all the engine folk how the same unit could help them all, which it could. Probably strength of spark was the only key factor of difference. You would need a stronger spark to deal with a larger swept volume within a cylinder, so the coil would need to be larger to serve a larger engine. I need an assistant to put their finger into the points gap. Come to think of it I wonder if octane values in fuel influenced spark strength ?
Actually, even considering the ‘Jupiter Scandal’ of the Paris Salon,
What scandal ?
the Jupiter was built in very modest numbers, some 7000 only, considering the later Bristol and Rolls-Royce efforts; no wonder Jupiter parts are so hard to come by.
Does this include licensed production or only British production ? What is the corresponding ratio of RR V12 production during this period ? I wonder how many contemporary Pratt & Whitney Wasps were made at the same time? I guess that more of the others survived because you just get to stumble over more of the others, and very little Jupiter. I would punt that Jupiters, including licensed production, were far more common than any other manufacturers product in their day, and far, far less has remained. Probably there was a period from 1940 to 1960 when more could have been saved, but the Bristol family cringed at doing so. Things seem to crystallise in history on parallel pathways to fact : Spitfires won the Battle of Britain. It is more plausible that a 18 year old today picks a Jupiter as a Pratt & Whitney and disputes that any such thing could ever have been made in Britain, while a Packard Merlin will always be British.
powerandpassion:highly_amused:
I would also like to throw my hat in the ring with regards to obtaining it should you decide to part with it :eagerness:.Bob T.
Hey, I grovelled first !:)
Come to think of it you see Smiths, Negretti Zambra, Zenith – who were the companies that made these things? There seems to be more concise, structured information on things like Luftwaffe compasses on the web than Allied instruments. Is there a website somewhere that tabulates British instruments and makers ?
powerandpassionPratt & Whitney R-1830 Twin Wasp.
Sorry, didn’t see your post about my Kestrel rods; I’ll have to think about it.
Thank you for the P&W ID.
Kestrel rod experiments are part of this thread on Gilman bearings :
http://forum.keypublishing.com/showthread.php?128767-RR-Kestrel-Gilman-bearings&highlight=
Latest is to stay entirely away from berryllium copper, highly, highly toxic !
But enough information has now been gathered to try and rediscover the lost process of centrifugally cast copper lead bearings…
powerandpassionA fair few
Hi I have just joined the forum.
I came across this Altimeter recently and would be grateful as to any information as to what aircraft it could have been fitted to.
Matt
Coffin Dodger (!), welcome and great find. The Mark VB altimeter is listed in the 1930 ‘General Instrument Equipment for Aircraft’ and would feature in any of the silver biplanes of the 1930’s : Hawker Hinds and Demons to things like Vickers Vildebeestes and Vincents. Anything with two wings and a pilot with a moustache doing unauthorised loops.
I would happily give you an arm for it, so if you want to sell, please consider!
powerandpassionTest rig
I’m sure I’ve seen a photograph of one somewhere; possibly in the later Rolls-Royce Heritage Trust reprint of ‘By Jupiter’? I’ll have to dig it out; due for a re-read anyway!
Here it is, but a sleeve valve test rig, from Bristol publication “the Power Behind their Wings.”
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I assume the single cylinder Jupiter test rig would look something like a motorbike setup, running off a starter magneto.
Does anybody know how to calculate the size of a carburettor to serve the appropriate fuel charge to a single cylinder ?
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