question DD Screens

[Jack]

Just thinking out loud here and thinking about new things on the show scene.

 

How difficult would it be to make an inflatable screen for a DD tank - what would be involved in making one - may be just for show?

[Big Al]

Jack there is one on the show scene owen by John Pearson who is on this forum. The screen is operational and inflats by compressed air, we spent most of last winter getting to work.

Big Al

[John Pearson]

That is a strange question Jack and of course I am fascinated why you would be asking it? Do you know of naked a DD (Sherman perhaps?) that might need one?

 

Anyway, how difficult depends on what you are trying to do: if you want one for a film that is not capable of raising it is not too difficult as when folded down, very little of the screen mechanisms show except the locking legs, details of these are easy to find and I have examples of both Sherman and Valentine to copy.

 

If you want it to work then there is a quantum leap in difficulty and a lot of fabrication of the air system etc to add. You also need the tubular frames although the screen erects and stays up by air pressure alone so strangely, the locking legs do not need to be made unless the screen is going to be seen down as well as up.

 

If you are thinking of remaking a 'genuine' screen, correct in all the details, fully operating in the original manner made of original spec materials then you are really taking on a task, no mistake.

 

Why do you ask?????

[AlienFTM]

If you want it to work then there is a quantum leap in difficulty

 

http://en.wikipedia.org/wiki/Quantum_leap

 

In physics, a quantum leap or quantum jump is a change of an electron from one quantum state to another within an atom. It appears to be discontinuous; the electron "jumps" from one energy level to another very quickly, after existing briefly in a state of superposition. The time this takes relates to the pressure broadening of spectral lines (see the section Pressure Broadening in that article). The phenomenon contradicts classical theories, which expect energy levels to be continuous. Quantum leaps cause the emission of electromagnetic radiation, including that of light, which occurs in the form of quantized units called photons.

In the vernacular, the term quantum leap has come to mean an abrupt change or "step change", especially an advance or augmentation. The term dates back to early-to-mid-20th century, coinciding with the discoveries of quantum mechanics. The popular and scientific terms are similar in that both describe a change that happens all at once (revolutionary), rather than gradually over time (evolutionary), but the two uses are different when it comes to the magnitude of the change or advance in question.

In real physical systems a quantum leap is not necessarily a large change, and can in fact be very insignificant.

 

Probably the smallest jump in the physical universe.

 

Oh how we abuse our language.

[Maurice]

great project , what if I would supply an M4A1 , then you could experiment with it ?

[kpu121265]

Whilst i can't answer the question, and am curerntly busy trying to get the Sherman up and running, never mind floating/swimming.... I do have copies, dated April '45 of some of the mods to the screens for DD tanks. Unfortunately, despite the last sentence, these cover the internal fittings, pipe work, compressor etc but do contain some before and after line drawings of the forward lower crew compartment and as you would imagine detail of the pipe works etc for the 'upgrade'.

Whilst it doesn't help with the skirts, i am happy to make the documentation available to anyone who would benefit from seeing it.

Regards

Ken

[John Pearson]

http://en.wikipedia.org/wiki/Quantum_leap

 

 

 

Probably the smallest jump in the physical universe.

 

Oh how we abuse our language.

 

Are you a pedant or merely being pedantic?

 

How do you know I was not actually referring to an American television programme with Steve Baluka (sp?) called Quantum Leap where he time travels and then is set a task that is so hard he is told he is 97% or somesuch likely to fail?

 

I was only implying that the task became immediately more difficult, once the realism required increases, exactly as the electron appears to move. I certainly did not imply that the task was only made more onerous by the tiny energy requirement to lift an electron from one shell around a nucleus to another!

 

By the way, the cat is either alive in the box or it is dead, not both! Making DD screens is either easy or hard but not both at the same time, no matter how often you measure the job.

 

Am I trying to be obscure: too damn right!

 

By the way, as you take me so literally, I must remember to NEVER express mild disbelieve in your presence with 'well b*gger me!!!'

[John Pearson]

Whilst i can't answer the question, and am curerntly busy trying to get the Sherman up and running, never mind floating/swimming.... I do have copies, dated April '45 of some of the mods to the screens for DD tanks. Unfortunately, despite the last sentence, these cover the internal fittings, pipe work, compressor etc but do contain some before and after line drawings of the forward lower crew compartment and as you would imagine detail of the pipe works etc for the 'upgrade'.

Whilst it doesn't help with the skirts, i am happy to make the documentation available to anyone who would benefit from seeing it.

Regards

Ken

 

I have full details of the DD system, handbooks, parts list, photos and even an explanatory video of how it works if anyone is planning to make one. But why???

[Adrian Barrell]

Prior to the 1994 Normandy Tour, I was asked by Neville Anderson at the Tank Museum if I would consider restoring my Sherman as a DD to enable an amphibious landing at Arromanche......

 

At that time there still was, I think, the remains of a DD at Battlesbury Bowl with the prop bevel boxes still fitted. However, the scale of the problem and the time involved made it a non starter for me. Anything is possible but....

[Jack]

That is a strange question Jack and of course I am fascinated why you would be asking it? Do you know of naked a DD (Sherman perhaps?) that might need one?

 

Anyway, how difficult depends on what you are trying to do: if you want one for a film that is not capable of raising it is not too difficult as when folded down, very little of the screen mechanisms show except the locking legs, details of these are easy to find and I have examples of both Sherman and Valentine to copy.

 

If you want it to work then there is a quantum leap in difficulty and a lot of fabrication of the air system etc to add. You also need the tubular frames although the screen erects and stays up by air pressure alone so strangely, the locking legs do not need to be made unless the screen is going to be seen down as well as up.

 

If you are thinking of remaking a 'genuine' screen, correct in all the details, fully operating in the original manner made of original spec materials then you are really taking on a task, no mistake.

 

Why do you ask?????

 

Many thanks John,

 

My line of thought is this - it is always nice to keep pushing the boundaries of the hobby and to make sure we always have something new to look at and wonder.

 

I have the passion and the vision for such things but no talent to do it! But for Armour & Embarkation wouldn't be wonderful to have a line of Sherman's with your tank lined up in Dorchester - what I way to blow the publics mind away....

 

 

But raising the game further wouldn't it special, worthy and a challenge to make one from the details you and others have? and demostrate it at shows.

 

...that would be exciting stuff!!!?

 

 

Kind regards.

 

Jack.

[AlienFTM]

Are you a pedant or merely being pedantic?

 

How do you know I was not actually referring to an American television programme with Steve Baluka (sp?) called Quantum Leap where he time travels and then is set a task that is so hard he is told he is 97% or somesuch likely to fail?

 

I was only implying that the task became immediately more difficult, once the realism required increases, exactly as the electron appears to move. I certainly did not imply that the task was only made more onerous by the tiny energy requirement to lift an electron from one shell around a nucleus to another!

 

By the way, the cat is either alive in the box or it is dead, not both! Making DD screens is either easy or hard but not both at the same time, no matter how often you measure the job.

 

Am I trying to be obscure: too damn right!

 

By the way, as you take me so literally, I must remember to NEVER express mild disbelieve in your presence with 'well b*gger me!!!'

 

I wasn't picking on you in particular, but rather demonstrating how the vernacular use of an expression can completely change it.

 

Sorry if it offended.

[John Pearson]

I wasn't picking on you in particular, but rather demonstrating how the vernacular use of an expression can completely change it.

 

Sorry if it offended.

 

No offence taken.

In fact, quantum physics has a military connection to me! My no2 son is a Navy Helicopter pilot and is currently between his second and third tour in Afghanistan because there are not enough of them. Anyway, when he was at Cambridge doing Aeronautical Engineering MSc, I had to take him back and forth to Uni. We would talk about all sorts but the more tired I was,the more complicated the discussion so as to keep me awake because I got into the argument. The more obcure the better: complex numbers, theretical time travel, ex NASA gadgets that they had in the labs etc but the best one was quantum physics! He actually understood it but could not explain it: I was too dim to grasp it, despite loads of trying. I well remember that looking at or measuring something changes it (what??) and the Schroedingers (sp?) cat was both alive and dead at the same time in the box. Sounds like utter garbage to me but puzzling over it kept me awake while driving back and forth.

 

No 2 son's Sea King got punctured by mg bullets last time so I am not looking forward to him going back next time.

[John Pearson]

Many thanks John,

 

My line of thought is this - it is always nice to keep pushing the boundaries of the hobby and to make sure we always have something new to look at and wonder.

 

I have the passion and the vision for such things but no talent to do it! But for Armour & Embarkation wouldn't be wonderful to have a line of Sherman's with your tank lined up in Dorchester - what I way to blow the publics mind away....

 

 

But raising the game further wouldn't it special, worthy and a challenge to make one from the details you and others have? and demostrate it at shows.

 

...that would be exciting stuff!!!?

 

 

Kind regards.

 

Jack.

 

I can certainly help with info if anyone wants to make one. For example: did you know that the propellor drive units are based on Ford Model T back axles??

[AlienFTM]

No 2 son's Sea King got punctured by mg bullets last time so I am not looking forward to him going back next time.

Then I shall watch the news and listen out particularly for Sea King crews and hope I don't hear, along with the Light Dragoons BG (who are sadly being killed every week due to their leading the surge started by Op Panther's Claw). Not that I don't feel bad about deaths outside the BG - it's just that the LD casualties might be the sons of my friends.

 

The LD must be due to return soon, without further casualties.

[mcspool]

Jack,

 

Your idea could be closer to reality than you think. One of the Sherman DD´s in France is for sale: http://www.armyjeeps.net/swimtank/1943_sherman_m4.htm

 

Personally, I would hate to see this relic restored to running condition. There are many olive drab Shermans with white stars around, but hardly any battle relics with known history. I feel this tank is more valuable in its current condition than being restored.

 

Hanno

Edited October 9, 2009 by mcspool

[Adrian Barrell]

Jack,

 

Your idea could be closer to reality than you think. One of the Sherman DD´s in France is for sale: http://www.armyjeeps.net/swimtank/1943_sherman_m4.htm

 

Personally, I would hate to see this relic restored to running condition. There are many olive drab Shermans with white stars around, but hardly any battle relics with known history. I feel this tank is more valuable in its current condition than being restored.

 

Hanno

 

 

Here here!

[Jack]

Jack,

 

Your idea could be closer to reality than you think. One of the Sherman DD´s in France is for sale: http://www.armyjeeps.net/swimtank/1943_sherman_m4.htm

 

Personally, I would hate to see this relic restored to running condition. There are many olive drab Shermans with white stars around, but hardly any battle relics with known history. I feel this tank is more valuable in its current condition than being restored.

 

Hanno

 

 

Thanks Hanno and have to agree with you - there is something so spooky about that tank and we know the reasons why. This tank is a real chance to time travel.

 

Do you know why it is for sale?

 

In your judgement would you say that this is one of the most historic Shermans in the world?

[mcspool]

Do you know why it is for sale?

Jack,

 

No idea, and when I first saw it I thought for a few seconds it was a scam.

 

Possibly it is as simple as the fact that the museum´s owner needs the money? At least the seller acknowledges it is a historic artifact. Would like to learn on what Mr Schuster based his appraisal, though.

 

If indeed it gets sold, I hope it only changes ownership and stays in Normandy.

 

My EUR 0,02 worth,

Hanno

 

Quote from ad:

1943 Sherman M4-A1 Duplex Drive

 

This Sherman Tank sank off the coast of Normandy France at Omaha Beach on June 6 th. 1944. This Tank along with several artifacts were recovered in 1974, only 2 others have been recovered for a total of 3. There were 32 Sherman Duplex Drives to go ashore, 31 were launched and 29 sank and the 2 that made it in were destroyed in combat.

It is an extremely rare piece of Military History that is being offered as what it is, a Historic artifact in as found condition. The asking price is the appraised value which was done for the U.S. Army by Dick Schuster several years ago.

Price: $595,000.00

Tanks location : Port En Bessin, Normandy France

 

[mcspool]

In your judgement would you say that this is one of the most historic Shermans in the world?

Definitely. There are more Shermans tanks off the coast still on the seabed. But this one was recovered and put on display, which makes the history it represents a bit more tangible for the public.

 

Of course there is another Sherman DD at Courseulles, equally important because it is a genuine battle relic. There a handful dotted around France, preserved in the stop where they were put out of action. Another example is the Sherman at Cassino in Italy. And of course Cobra King, as dicussed on this site.

 

So when you start counting, indeed at least a few dozen Shermans have a known battle history, but in general it is very rare for a surviving Sherman (or any other tank for that matter) to have a known history.

 

H.

[kpu121265]

This must be the Musee Des Epaves selling up, or selling off some of the silver. I've met Jacques Lemochou (can't remember how to spell his name though) and he was a really interesting chap. Originally he was contracted to pull this stuff off the sea bed to reduce the danger to fishermen and the like. He was enterprising enough to decide to keep some of it rather than handing it over to the scrap man - and thank goodness he did. That museum is a very moving tribute to the landings in my opinion. Unfortunately i think he passed away last year, and the last couple of times i've driven past the museum it's been shut.

Ken

[Grasshopper]

Went to that museum this year during our Normandy trip. It was pretty awesome. Was also entertaining trying to turn round and park our 2 half tracks in there small car park!

[mcspool]

This must be the Musee Des Epaves selling up, or selling off some of the silver. I've met Jacques Lemochou (can't remember how to spell his name though) and he was a really interesting chap. Originally he was contracted to pull this stuff off the sea bed to reduce the danger to fishermen and the like. He was enterprising enough to decide to keep some of it rather than handing it over to the scrap man - and thank goodness he did. That museum is a very moving tribute to the landings in my opinion. Unfortunately i think he passed away last year, and the last couple of times i've driven past the museum it's been shut.

 

Ken,

 

I did not know that about Jacques Lemonchois. Just googled his name and found out he indeed passed away in July 2007. I talked to him back in 2004, and as you say he was a very interesting man. He really believed that the force of the objects in his museum was in their state. I am very glad he had this vision and did not slap olive drab paint and white stars all over everything.

 

As with most of these types of museum, once the founder, financier and driving force behind it passes away, the museum and its collection slowly dies with it. Sad it seems this is happening with the Musée des épaves sous-marines du Débarquement also.

 

Hanno

[Enigma]

I don't really see a problem restoring to running condition.

Its history IS known so restoring wouldn't erase that.

[CommanderChuff]

There was a TV programme recently about a chap who made a Scorpian tank float. He built a home made DD frame and screen based on the Sherman design. It worked, the tank floated but unfortunately the hull wasnt as waterproof as it should have been. The test was curtailed by water ingress into the engine bay. But the screen inflated, deflated and was waterproof.

[Enigma]

There was a TV programme recently about a chap who made a Scorpian tank float. He built a home made DD frame and screen based on the Sherman design. It worked, the tank floated but unfortunately the hull wasnt as waterproof as it should have been. The test was curtailed by water ingress into the engine bay. But the screen inflated, deflated and was waterproof.

 

I've seen it, nearly a submarine.

Still the concept worked (again).