GRANVILLE Posted 14 February , 2012 Share Posted 14 February , 2012 I came across this in the pages of a Meccano Magazine! It had a very brief article about a George Constantinesco who it would appear devised a mortar that could be fired almost silently via compressed air (I presume). Unfortunately his first effort was turned down as it could only throw the bomb 150yrs and many trenches were much further away. He apparently soon came up with something much more capable, but I think the war was about over by then. Searching the Internet I've found this much more informative web site on the man and his several inventions. Dave Upton http://www.gs-harper.com/Mining_Research/Power/sonics002.asp Link to comment Share on other sites More sharing options...
CharlieBris Posted 14 February , 2012 Share Posted 14 February , 2012 Compressed air mortars were widely used by the Central Powers (the Luftminenwerfers) but the invention of George Constantinesco seems to have used highly compressed oil as the driving medium. Looking at the image of the mortar it seems to have been a fairly massive construction to handle the high pressures of around 30,000 psi. I'd guess it used a free piston to drive the mortar bomb. Regards, Charlie Link to comment Share on other sites More sharing options...
centurion Posted 14 February , 2012 Share Posted 14 February , 2012 No he didn't. He used compressed water and compressed oil. Since physics lessons normally teach that you cannot compress liquids no one took it seriously (even though he actually built and demonstrated such mortars - I suspect that some scientists firing neutrons from Cern would probably know how he felt.) Compressed oil mortar Link to comment Share on other sites More sharing options...
GRANVILLE Posted 14 February , 2012 Author Share Posted 14 February , 2012 I admit I've not read the website article about this, I noted the word 'compressed' and assumed it must be air, but judging by the damp looking sheen around the posted picture I'm sure Centurion will be right about the process involving oil. I wouldn't like to try and feed it in nailed boots! Dave Upton Link to comment Share on other sites More sharing options...
Terry_Reeves Posted 14 February , 2012 Share Posted 14 February , 2012 The Bellaires Trench Gun was another interesting device: http://tinyurl.com/72n3kv6 Invented by Alan De Mowbray Bellaires RNVR, RM, who also served briefly with the RE Special Brigade. Bellaires eventually managed to get the device patented in 1917 and it was apparently taken up by the Italian Army, although I have no evidence to what extent. http://tinyurl.com/7xtjj3f One member of the Special Brigade left behind an interesting account of a demonstration of this device: "Christmas Day (1915) was one of fine weather. There were no parades, but a party of of us were detailed to assist a certain Capt. Bellaires in matters relating to an ingenious gun he had invented. It was a bulky contrivance devised to fire a number of bombs simultaeneously, the propelling force being an explosive mixture of hydrogen and oxygen supplied in correct proportions from cylinders of these gases. This remarkable gun had four barrels, each of which could hold sixteen missiles of the Mills Bomb type, so that sixty-four of them could be thrown to burst in a confined area at a distance of about 300 yards. We conveyed the gun to some demonstration trenches, and man-handled it into position. Then we waited around while Bellaires discussed various problems with several officers. All this completed, we carried the gun out again, and made for home. As mere pawns in this game, we were quite content to do as we were told and leave the responsibility to others." "....Two days later, we were on fatigue once more with Bellairs' gun. A longer journey this time took us to some open fields beyond Bethune. Having fixed the gun in position on a sort of firing range, we awaited the arrival of Staff Officers. They were abominbaly late, and so we hung around while Bellaires tested his apparatus and filled the explosion chamber with the gases removing the safety-pin from each Mills Bomb as a sergeant passed them to him, he slid sixteen bombs down each barrel and sighted the gun. At last there was a clatter of horses and riders as a batch of Staff galloped over the field and reined near us. The General dismounted, chatted with Bellairs, and examined the gun. The others remained on horseback, moving away somewhat to witness the spectacle while at the same time feeling safer, and the General peered into the barrels. The signal was given, and the gun went off. A shower of bombs hurtled through the air, and burst on their target. We all proceeded to see what the effects had been. The result did not appear to be devastating, and the General was obviously not impressed. Mounting, he spoke briefly to Bellaires, finishing with the terse comment, "Come back when you have something which will fire half a ton". Turning away, he quickly rode off, and his staff hurriedly followed. Bellairs looked depressed at such a summary dismissal. The gun was packed up, accessories and all, and we returned to Chickory. We were never asked again to give demonstrations, and shortly afterwards "Billy Bellaires" departed with his chauffeur, fur collar and gun." Martin Sidney Fox, "Corporals All - With Special Brigade RE 1915-1919" Privately published, 1965. TR Link to comment Share on other sites More sharing options...
centurion Posted 14 February , 2012 Share Posted 14 February , 2012 I admit I've not read the website article about this, I noted the word 'compressed' and assumed it must be air, but judging by the damp looking sheen around the posted picture I'm sure Centurion will be right about the process involving oil. I wouldn't like to try and feed it in nailed boots! Dave Upton Here are the compressed oil and the compressed water mortars. From what I've read they both had ranges in excess of compresed air and/or the Stokes but as everybody knew you can't compress liquids so it must be some kind of trick and it was invented by a mad Romanian so it must be some kind of trick it was not proceeded with and so George Constantinesco went off and developed a very successful synchronisation system for aircraft machine guns Link to comment Share on other sites More sharing options...
centurion Posted 15 February , 2012 Share Posted 15 February , 2012 Compressed air mortars were widely used by the Central Powers (the Luftminenwerfers) And the French and Italians Link to comment Share on other sites More sharing options...
centurion Posted 15 February , 2012 Share Posted 15 February , 2012 The following links may be of interest http://www.spudfiles..._mortar_268.jpg http://www.historicr...pn%20Mortar.jpg http://www.warrelics...nd-000_0001.jpg http://landships.act.../french-mortar/ A cross section of a round Link to comment Share on other sites More sharing options...
GRANVILLE Posted 15 February , 2012 Author Share Posted 15 February , 2012 And the French and Italians Surely to goodness they are using more than a pair of bike pumps to power it??! Link to comment Share on other sites More sharing options...
truthergw Posted 15 February , 2012 Share Posted 15 February , 2012 I can't understand why compressed fluids would be thought of as ' not possible '. There was nothing new about hydraulic machines. Hydraulic jacks had been used to build bridges. A hydraulic machine tested anchor chains. Bramah is the name most readily associated with the technique. We are not talking about the technological dark ages here. The vast majority of the London Underground was in operation. Many of the lifts which accessed the lines were hydraulic. Link to comment Share on other sites More sharing options...
centurion Posted 15 February , 2012 Share Posted 15 February , 2012 I can't understand why compressed fluids would be thought of as ' not possible '. There was nothing new about hydraulic machines. Hydraulic jacks had been used to build bridges. A hydraulic machine tested anchor chains. Bramah is the name most readily associated with the technique. We are not talking about the technological dark ages here. The vast majority of the London Underground was in operation. Many of the lifts which accessed the lines were hydraulic. The liquid in these hydraulic systems is under pressure but is not compressed - that's why they work so well. Liquids can be compressed but only by a very small amount (but a lot of energy gets stored). At the time it was generally believed and taught that water is not compressible (and for most practical purposes this is correct). Link to comment Share on other sites More sharing options...
Staffsyeoman Posted 16 February , 2012 Share Posted 16 February , 2012 A minor point of order - and please do tell me to get back in my box if so - surely a mortar is inherently flashless (in the modern, C20+ sense) as it does not use flame-producing propellant, rather springs, etc.? Link to comment Share on other sites More sharing options...
centurion Posted 16 February , 2012 Share Posted 16 February , 2012 A minor point of order - and please do tell me to get back in my box if so - surely a mortar is inherently flashless (in the modern, C20+ sense) as it does not use flame-producing propellant, rather springs, etc.? The early trench mortars used black powder which produced a flash and smoke. The Stokes used cordite which does produce a muzzle flash visible at night (which is one reason why night fighters tended to have top wing mounted mg so as not to ruin the pilot's night vision). Those armies that made use of pneumatic mortars used them for night work as the invisibility made up for the lower fire rate. Link to comment Share on other sites More sharing options...
Tom W. Posted 16 February , 2012 Share Posted 16 February , 2012 Surely to goodness they are using more than a pair of bike pumps to power it??! Those are French marines. Bike pumps are all a marine would need. They also threw their bullets rather than firing them. Link to comment Share on other sites More sharing options...
centurion Posted 16 February , 2012 Share Posted 16 February , 2012 Those are French marines. Bike pumps are all a marine would need. They also threw their bullets rather than firing them. Thought they spat them! Most photos of pneumatic mortars show either a compressed gas cylinder being used or a chemical gas producer. However both were bulky and heavy and required manhandling through the trench system. It was possible on some models to charge the chamber by hand or foot pump as well (or instead of). It might well take time. However these were more powerful than a bicycle pump - more akin to that used on a car or lorry and think how much pressure you can get into one of those tyres. BTW since pneumatic mortars tend to be used at night most photos are posed anyway. The very first pneumatic trench gun (the Sims- Dudley) used in the Cuban and Porto Rico insurrections and in the subsequent Spanish American War (by TeddyRoosevelt’s Rough Riders and the 4th Ohio Volunteer Infantry) used a black powder charge in a separate enclosed cylinder to compress the air. Link to comment Share on other sites More sharing options...
CharlieBris Posted 16 February , 2012 Share Posted 16 February , 2012 The quoted pressure used in the Austro-Hungarian 12cm Luftminenwerfer was 35 Atm (525 psi) - the air was supplied by compressed air cylinders. Reading all of the article on George Constantinesco he also experimented with a gun which used a small explosive charge and a cylinder of pressurised fluid (oil?) to deliver energy to a projectile. The image of the gun seems to show projectile like the "toffee apple" mortar bomb without the stick. If it worked the gun was achieving fantastically high energy transfer rates to the projectile - much higher than a conventional gun. Regards, Charlie Link to comment Share on other sites More sharing options...
centurion Posted 17 February , 2012 Share Posted 17 February , 2012 The quoted pressure used in the Austro-Hungarian 12cm Luftminenwerfer was 35 Atm (525 psi) - the air was supplied by compressed air cylinders. Reading all of the article on George Constantinesco he also experimented with a gun which used a small explosive charge and a cylinder of pressurised fluid (oil?) to deliver energy to a projectile. The image of the gun seems to show projectile like the "toffee apple" mortar bomb without the stick. If it worked the gun was achieving fantastically high energy transfer rates to the projectile - much higher than a conventional gun. Regards, Charlie I've already posted two photos of this in this thread. If you look at the second you can see a hand pump. It did work but as I said no one believed it. Link to comment Share on other sites More sharing options...
CharlieBris Posted 17 February , 2012 Share Posted 17 February , 2012 The "silent gun" seems to have been a different device (attached). Caption in (ref) notes that a small explosive charge was used to compress the working fluid behind the projectile. Regards, Charlie Link to comment Share on other sites More sharing options...
centurion Posted 17 February , 2012 Share Posted 17 February , 2012 The "silent gun" seems to have been a different device (attached). Caption in (ref) notes that a small explosive charge was used to compress the working fluid behind the projectile. Regards, Charlie No its the same device as in the first photo I posted - just not elevated to it's firing position. It also appears in the 2nd photo (which also shows the pump) but on a slightly different carriage. Link to comment Share on other sites More sharing options...
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