powerandpassionBoulton Paul Sidestrand
Wulfie,
Here are a few pictures of Boulton Paul spar, as used in the Sidestrand, and, if you could post a picture to confirm, in the later Overstrand :
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BP promoted a system for creating spars of different size and performance out of standard sections. They were energetic innovators and many of their ideas indirectly travelled through to other Constructors.
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Here is a Boulton Paul pamphlet from 1929-30, detailing the steel construction of the Sidestrand. I would be happy to scan and send it to you for your display, if you PM a contact email. I have a request : Is it possible to secure a fingernail of your spar sample, to analyse its metallurgy ? I suspect it is DTD54a Nickel Chromium alloy steel, but I would like to confirm for certain.
Ed
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powerandpassionA further video (at 1 minute onwards) on Blue Streak, and, incidentally, official parsimony in aerospace, supports the use of 0.019″ stainless sheet in the pressurized fuel chamber.
https://www.youtube.com/watch?v=AIxSX2gYSec
This material gauge matches the spars of the Bristol Bulldog, a cross section example given below, showing flange thickness as 26SWG or 0.018″, so it is entirely possible that offcuts from Blue Streak could be utilised for Bulldog spars on the basis of gauge.
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The original material used in the Bulldog spar is DTD54a, a Nickel Chromium alloy developing, after heat treatment 65T ultimate strength, matching the values given for Firth Vickers Blue Streak material, so it is entirely possible that offcuts from Blue Steak/T188 could be utilised for Bulldog spars on the basis of strength.
Here is a piece of Bulldog spar today, demonstrating that the original Nickel Chromium steel is corrodible. These aeroplanes were not made to last. Certainly a Bulldog made out of FV448 would last a lot longer.
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Some 4000 rockets of all types were launched from Woomera in Australia, including a great number of Blue Streaks. So I will have to jump into a Landrover with a can opener and see if I can find some Blue Streak remains in the desert, cut a bit out and make up some Bulldog spars!
powerandpassionStarter Dog
I understand the Vintage Wings of Canada made a Hucks starter so should be able to advise on sizes :
Here are some photos of Hucks starter fitted to Hawker Australian Demon, care of South Australian Aviation Museum.
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Avanti, Ed
powerandpassionGood post Mustang 51.
I have had the pleasure of listening to Mustang 51 when Mosquito KA114 was unveiled in NZ, certainly one of the most extraordinary and memorable events I have attended. It was the first time I had actually heard a commentator stop when flyovers occurred, and allow the sound many had traveled a long way to see to be heard in full throat. The 45 degree rule was allowed to become the 90 degree rule, only interrupted by the spontaneous clapping of the crowd. Certainly a thoughtful, precise commentary which also involved calling up key folk involved in wartime flying and the restoration process to come up to the microphone and share some insights. I get the idea that the people who might know the most about an aircraft are not the best public speakers, but an informed, prepared commentator can draw out with thoughtful questions the basic excitement that drives these people to do the extraordinary things we want to know about.
The solution of to all this is to pay Mustang 51 to attend other airshows so you can hear the magic. Failing this to start a breeding program by sending vials of frozen Mustang 51 DNA around the world to willing surrogates. It will be a long wait but worth it!
powerandpassionEverything old is new again and the thread from the first iteration of strip steel construction to its space age expression is closely connected.
Below is a remarkable example of the first large scale commercial use of strip steel, in the ill fated airship R101, started in 1928. It used a version of ‘Boulton & Paul’ tube which was made form strip steel clenched together with a seam. At that time, cold drawn tube could not provide high strength, thin wall, tubular members with a consistent wall thickness. So Boulton & Paul, spirited innovators, devised a product made from ultra thin strip steel, formed into a tube, as modern resistance welded tube is made today, but closed with a seam, as the alloys were not amenable to the basic welding technology of the day. This sample of airship 101 is a remarkable artifact, lodged in obscurity on a shelf at Shuttleworth, testament to one of the largest state sponsored technology experiments of the time, that ended in tragedy as R101 crashed into the ground in France and was destroyed with great loss of life, ending Britain’s airship endeavours for all time.
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The Boulton & Paul tube is a heat treatable 12% chromium ‘stainless steel’, called in its day DTD46H. In this triangular member it is the tube that formed the longitudinal booms, being riveted to Duralumin sheets with lightening holes, to form the basic beams in the geometry of R101. It is a wonder that this artifact has survived. It is worth noting that the government hedged its bets with airship contracts, pouring its largesse into R101, but simultaneously letting out a contract, on stingier terms, to private industry, to make airship R100. This project was the first great engineering task of Barnes Wallis, later the innovator behind the geodesic construction of the Wellington, and I wonder how much pondering over the great Meccano task of R100 laid the seeds in his mind of geodesics. Another engineer on the project was the co-founder of Airspeed Aircraft and, later, author Neville Shute, who’s book ‘Slide Rule’ is a great record of the times. R100 was of pure Duralumin construction, as were the products of the Zepplin company, so the use of steel was a great curiosity in its day, dumbfounding the Germans, then and during the 30’s as the British aircraft industry embraced steel construction, while the continent and United States went for Duralumin.
Strip steel construction faded into obscurity post WW2, but was revived in the 1960’s for some remarkable projects. Here is a video for the Blue Streak rocket program, which ultimately developed into the Europa satellite launch system of today. The liquid fuel stage, made by Hawker Siddeley, used thin 0.020″ stainless steel to make a ‘beverage can’ structure that was barely self supporting. In the video, at 1 minute, the thin shell is pounded by a rocket chap and yields like foil. Once the shell was pressurized with fuel, however, it became impossible to make an impression on it, much like a modern can of unopened soft drink.
https://www.youtube.com/watch?v=NHALJGOEs8o
This remarkable stainless steel was Firth Vickers 535, or FV535, a 12% chromium steel, in its basic chemistry not too dissimilar to the material used in 1928 in airship R101. FV535 is a Ducati while DTD46H is a Penny Farthing in terms of material refinement and understanding of applications, but it is likely that the junior research assistant in the metallurgical lab of 1928 was the senatorial presence in the lab of the 1960’s, and had observed the development of flight from fragile biplanes of wood to rockets and jets puncturing the atmosphere. The FV 448 purportedly used for the Bristol T188 high speed jet was a simpler form of FV 535, but ultra thin strip FV535, according to my 1960’s Firth Vickers catalogue, shows strength values similar to the structural members of the Bristol Bulldog. So perhaps FV535 used in rocket shells, as the only strip steel material around in quantity 1962, that could be substituted, may have been purloined by the sticky fingered Bristol apprentices for their Bulldog project, with an agreeable nod from some silver haired metallurgist of the day. But we need somebody to fess up to prove the theory. Please.
powerandpassionThank you for all your contributions to this table, probably would be better hosted in a pub with free flowing beer, horses tied up at the front to take everybody home after! The Hives rice puddin’ reference is starting to get the picture, in the sense one Merlin equals 1,000 Clydesdales equals the Whittle jet engine. The whole enquiry relates to turning to a more innocent companion, a child or somebody capable of putting petrol into a diesel tank, and saying with an air of quiet, undeserved confidence : “that there is the equal of 50,000 Cydesdales,” or the Hivian 50 Merlins. Now we all know a Merlin with a broken crankshaft can generate 0 horses, and something off a Hornet a few more, but 1000 horses will do. The beauty of a thrust comment is that it can only arise in the moment, when something thrustworthy occurs. I am thinking of that time when the Russian pilot at Avalon Airshow in Australia in 1998 parked his Su-27 vertically 30 feet above the runway, then opened a bottle of vodka with his eye socket, then hit the gas and Yuri Gagarined the jet into the ******** of a seagull flying at 20,000 feet. I think he drained his tanks in 5 seconds, but it was an extremely THRUSTY moment. I wonder if anybody knows what sort of motor there is in an Su-27, and how many Merlins or Clydesdales spewed out of the tailpipe. I would also like to find out how many Merlins or wing’d Pegasi draw a single Trent through the sky at cruise of 700km/h at 30,000 feet, so I can converse with the 7 year old and impress him for 3 seconds. I do love the horse photos by the way, and have gained new ideas on attending airshows on a horse’s back, why pay for VIP seating when you can bring it under you?
powerandpassionI will add my tuppence and stand in the camp of the OP and would gladly participate in a mob lynching of some commentators or PA system suppliers who feel value for money is best provided by incessant muzak.
With old aeroplanes the folk who actually built them or operated them as the daily horse have the selfish habit of dying off, so it is hard for anybody to have a full understanding of all topics, a space which then tends to be filled in with verbal expanding foam.
More good things are happening as the internet age meets the Tannoy age, like a Tyrannosaurus sinking its teeth into cud chewing Tannoy-Brontosaurus :
a) On demand detailed content that can be accessed by scanning a barcode with your phone, replacing the bit of cardboard on the grass with the name of the aeroplane on it. (OK I am projecting to 2017)
b) Commentators with good sense inviting folk who actually restored or fly the aeroplane to talk about it, because they know what they are talking about. The smartest commentator would really just be an MC.
I have another gripe which is in visual presentation : we all look like anoraks with bad skin. How are we ever to breed in some better looking DNA if we all look like a Star Trek convention with comfortable elastic waisted trousers ? If I operated an airshow I would hire some models to stroll around, after a little boot camp where they would be taught some basics on Marstrand self centering castoring wheels and rate of fire from a 20mm cannon. Soon the airshow would be the ‘place to be’ allowing a higher statistical probability of transmission of anorak DNA into bodies that don’t chew hotdogs with their mouth open while excitedly gesticulating at the sky.
It is also important to fuel the fantasy that you can get into a seat in historic aviation without being on the wrong side of 50. So we need to build little hidey holes into the tarmac into which, before the show, we stick more models with good teeth in flight suits. As the aeroplane coasts to a stop the competent pilot backed by cashflow that has taken decades to accumulate can be replaced with the young model casually strolling back to the hangar.
Really I would be just happy if the commentator bit was sorted out, before somebody is beaten to death with half eaten hot dogs.
powerandpassionIn the Good Lord’s Book The Man injuncts via Matthew : “For I was hungry and you gave me something to eat, I was thirsty and you gave me something to drink, I was a stranger and you invited me in..”
And so I traveled as a pilgrim from the antipodes to the green fields of Shuttleworth during it’s last flying day and I was both fed and invited in – I want to thank the incredible community of volunteers and Trust staff who keep this phenomenon going.
Some impressions :
I expected roped off enclosures, irritated instructions to ‘keep away from the aircraft’ and pressing my nose against glass to try and glimpse some fusty jewel. I came too early, thinking that after an hour or so I would be impatiently through exhibits and then waiting for the flying display. Instead I found the SVAS offering a flightline inspection for the price of a gourmet hotdog, like an indulgent Caliph offering the keys to his harem. I couldn’t believe this. This was not possible. It was anti my unconciously burnished image of the joy killing, finger wagging museum prison warder that seems to grow like mould in some places, suffocating them. I couldn’t put my money into the hands of SVAS fast enough – worried that it was all a dream and at any moment someone would arrive to announce the idea was over. The sun was out. That’s it ! Sunstroke ! The English had gone mad ! I stumbled dumbstruck into the flight line. A convivial SVAS volunteer accompanied a motley group of us into a Bristol M1, Hawker Hind, Mew Gull dreamscape. I have been conditioned, now that I reflect upon it, by some paranoid antipodean custodians of our universal heritage : I take it for granted that people like me, who adore historical aviation, must be carrying screw drivers to rip into the wings of priceless artifacts. Surely the SVAS man must be carrying a taser in case I started to rip the control column out of something ! I need to alert him to the odious danger posed by members of the public. I asked him if, in the history of this folly of letting folk amongst aircraft there had been any damage. ‘No, we try to encourage people to get close.” I looked carefully at him for some sign of Gestapo cruelty, some game meant for me to relax my guard, become actually happy next to a rare, priceless aircraft, before a sparking cattle prod was rammed into my spine. But only beads of perspiration formed upon his brow, surely the sign of sun induced pychosis. So I pushed it. “Is it OK for me to place my nostrils here?” indicating a proximity to an aircraft that in other places would land me a decade in Gitmo. “Go for it”. I was into those aeroplanes like a dog that meets another dog on the pavement! It was the most extraordinary introduction to the Collection that I now understand is driven by an extraordinary culture of access. I resolved two things : (a) I filled a bottle with water from the place, that as I go around the world I will quietly add to the water supply of any place that thinks a museum is a prison. (b) faced with a choice of leaving my money, if any, to grasping relations or a poodle called Mitzy, I now have a third option, which is a bit for the Shuttleworth Trust, and if they’ll take Mitzy, the whole bloody lot!
One of the reasons I came to Shuttleworth was to see the 1934 Comet Racer, in the air. I have stood many a time on the finishing line at Flemington Racecourse in Melbourne, and it was the closing of the circle to see Grosvenor House, an extraordinary survivor, not a stuffed animal in a case, but a still snarling tree cat. It was a half day before the flying display was to begin, and I was not ready for this tree cat to pounce on my shoulders and sink its spine chilling fangs into my neck. First came the sound. What was a Mosquito doing flying here? was the first dumb linking of neurons in my skull. I looked up. There it was. Red. It sounded like a Mosquito. Not like KA114 in New Zealand that caused the springs and wax to spurt out from the ears, but it sounded like a Mosquito! And there it was practicing, all for me, in an empty carpark. It was a sublime moment, the best closing of the circle I could have wished for. Thank you. Again the confused thought : surely this was against the law, this thing flying. But now I figure this is the act of maturity, a people in a comfortable relationship with their history, something that stretched back and recognised that loss is regrettable, but normal. In fact the whole Trust had its genesis in the loss of a beautiful son and the celebration of what gave him joy. So fly on Grosvenor House, and thank you.
I really loved my day at Shuttleworth and ran out of time to see it all. I came in at 9am and left at 9pm, and left like a kid let loose on a strawberry farm, stuffed with berries and covered in juice, looking regretfully back to rows of uneaten fruit as the gate was shut on me.
Veni, vidi. Vici, by you, Shuttleworth, old girl.
powerandpassionpowerandpassion, would love your input on this thread
PLA you share an acronym with an armed force that is gearing up and backed by a fairly solid Treasury so I will be circumspect in giving out too many ideas! I also don’t know what CAS is, assuming it is related to Ground Attack.
The key influence are the disruptive technologies that allow you to refine the ideas of the past. Eg welded tubular steel airframes and welding robots, which linked to a geometry that accomplishes structural outcomes and ease of weldability may open up a new lease of life for strong, slow moving, cheap steel platforms.
My contender in terms of regurgitating the past is the Link Trainer. In simple terms the pilot in the hot seat above the battle is obsolete. By that I mean you can supply five expendables operated remotely by one pilot, and as one vehicle is expended, the pilot toggles to another. Human intelligence will always be superior to robot intelligence, particularly for the powerful quality of restraint, when one trigger happy fool or program written by a fool can create cascading negative political consequences. When restraint doesn’t work out then this shouldn’t mean the expensive to train and replace pilot needs to be shot at. An expendable also doesn’t need seat armour or armoured glass or space for a pilot, so is smaller, lighter and can carry more business. So a Link Trainer, using goggles. That’s about it, if you want to find out more drop a few landing craft on the beaches of Australia in 2025.;)
powerandpassionMore
I do have strength values from the 1947 version of AP970 vol 1 section 401 and am looking into the chemical composition further.
Some further data :
BS S65 65 ton Ni-Cr steel C .22-.28, Si .3, Mn .35, S .05, P.05, Ni 2.75-3.5, Cr 1-1.4, Va .25, Mo .65, Tu 1
Source : “The Materials of Aircraft Construction”, FT Hill, this comes in five editions from 1933 to postwar, all consistent on S65.
DTD 331 80-90 ton Ni-Cr steel C .25-.4, Si .35, Mn .7, S .05, P.05, Ni 3-4.5, Cr .75-1.5, Va .25 (optional), Mo .2-.65, Tu 1(optional)
Source : “RAAF Publication 314 1944 Aeronautical Engineering Handbook”
The above source gives En28 as a substitute for DTD331 in 1944.
GAF (Aust) “Alternative Materials Drawing M3-00-50” & “SD26”, postwar, gives DTD 331 as an alternative to S99 ‘not exceeding 2 1/2 inches dia’
This information is to assist you on your journey and you must only rely on a qualified engineer in respect of making material substitutions.
powerandpassionGood to hear that it will be in NEIAF colours, an under explored part of WW2 history. Good effort. Big Effort!
powerandpassionthis may be a different topic, but would anyone have a copy of DTD331 and S65 steel specifications?
Like a classic song by Vera Lynn, redubbed with a doof doof backbeat, these metallurgical compositions are the same things today as they were then, except the costumes are different. The best way to answer your question is directly and indirectly.
Directly.
You may purchase a historical copy of S65, in an iteration pertinent to the period of your aeroplane, from the British Standards Institute. It will cost a bit, but all funds go to preserving their library and making it accessible, which is a worthy thing to support.
You are unlikely to find a copy of DTD 331, as original DTD specifications have not tended to survive.
Indirectly.
One way to resolve this is to reduce the specifications to chemical composition and ultimate strength value, then you can translate this through the maze of classification systems over time to an equivalent specification today, which then can be laid at the feet of an engineer poet to rule on. An engineer poet is someone with balls, imagination and a lust for results, and if you find one, don’t let them go!
S65 is 65T Nickel Chromium steel bar (1944) and DTD 331 is 80-90T Nickel Chromium steel bar (1944).
Here are some clues :
S65 in bar form is probably S88 in strip form and DTD 331 is probably T2 in tube form.
During the war, the powers that be sought to simply many different alloys in a small group of absolutely essential alloys, called the Emergency Number, or EN.
Most engineers practicing in the 1950’s to 1990’s would be familiar with EN, and your class of product falls into the EN25-EN26 type of steel.
This is different from today’s EN ‘Euro Norm’, which has given us Greece.
Today you may purchase bar from France called 35NCD16 in bar form that you may find matches your original specs. This product is used in the undercarriages of Airbuses and is cloaked in all sorts of continental proprietory names.
I am assuming S65 and DTD331 were used for highly stressed structural members like wing spar pins.
Let us know how you go.
powerandpassionGood piece of paper to find which shows extensive use of wood type props with Merlin – Griffons :[ATTACH=CONFIG]239980[/ATTACH]
powerandpassionMay 1936 Hendon, Empire Air Day
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powerandpassionThe MMP books by Alex Crawford, ‘Hart Family’ & ‘Fury & Nimrod’ are the perfect primers and long remain faithful companions in my journey.
The Kestrel engine common across these types certainly give a ‘look and feel’ of grace and ‘business’ to these types.
Once you start to get into the detail of these designs interesting, practical and brilliant personalities behind these aeroplanes start to become apparent, like an old Polaroid shot developing : Fred Sigrist, who developed the Hawker system of construction, which in myriad ways causes the eye to see the same DNA in all the types; Sidney Camm, who put outward slanted interplane struts into a single bay biplane design, with dihedral and sweep back, that gave the 700HP Kestrel engine the wrapping it deserved and Tom Sopwith, who had the rare wisdom of spotting genius like Sigrist and Camm and freeing it and pushing it to create, when these first appeared in 1929, a sensation.
Eighty five years later these are still formidable machines, and the crackling sound of a Kestrel surprising and good, very good.
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