RammyLad1 Posted 11 April , 2012 Share Posted 11 April , 2012 A bit of an unusal question but would anyone happen to know what speed, for example a piece of shrapnel, would be travelling at at the moment of explosion. Duncan Link to comment Share on other sites More sharing options...
spconnolly007 Posted 11 April , 2012 Share Posted 11 April , 2012 About 200 ft per second, according to wikipedia, if thats any help? Sean Link to comment Share on other sites More sharing options...
BPJermyn Posted 11 April , 2012 Share Posted 11 April , 2012 Would it not depend on the type of shell? Link to comment Share on other sites More sharing options...
rksimpson Posted 11 April , 2012 Share Posted 11 April , 2012 Hi Or you could simply use this example to work it out- http://www.physicsforums.com/showthread.php?t=267934 Thats if you have a physics degree for me this sounds easier- http://en.wikipedia.org/wiki/Shell_(projectile) and http://en.wikipedia.org/wiki/Shrapnel_shell All I know is that it makes a mess of what ever it hits! ouch regards Robert Link to comment Share on other sites More sharing options...
RammyLad1 Posted 11 April , 2012 Author Share Posted 11 April , 2012 Would it not depend on the type of shell? I realise that this could be a ' how long is a piece of string ' question, as you say , what type of shell. I'm trying to get an idea of the rate of miles per hour a piece of shrapnel would hit some unfortunate soul in its way. Link to comment Share on other sites More sharing options...
RammyLad1 Posted 11 April , 2012 Author Share Posted 11 April , 2012 Hi Or you could simply use this example to work it out- http://www.physicsfo...ad.php?t=267934 Thats if you have a physics degree for me this sounds easier- http://en.wikipedia....ell_(projectile) and http://en.wikipedia..../Shrapnel_shell All I know is that it makes a mess of what ever it hits! ouch regards Robert Robert, from the link the terminal speed is 400 feet per second. if there are 5280 feet in a mile that makes the mph ........ I knew I should have paid more attention at school. Duncan Link to comment Share on other sites More sharing options...
MikB Posted 11 April , 2012 Share Posted 11 April , 2012 Robert, from the link the terminal speed is 400 feet per second. if there are 5280 feet in a mile that makes the mph ........ I knew I should have paid more attention at school. Duncan Think of a ball from a carelessly-loaded highwayman's pistol at about 30 paces. Lethal to the unprotected, but capable of being stopped, diverted or much reduced in energy by quite light cover. Regards, MikB Link to comment Share on other sites More sharing options...
bruce Posted 11 April , 2012 Share Posted 11 April , 2012 400 feet per second divide by 5280 multiply by 60 (seconds in a minute) and by 60 again (minutes in an hour) Thus 400 x 60 x 60 divided by 5280 272 miles per hour. I taught history, not maths, so I hope someone can correct anything wrong in the above figures. I know shells weren't in the air for an hour, but at that speed, whatever a shell hit, it made a bit of a mess of it! Bruce Link to comment Share on other sites More sharing options...
RammyLad1 Posted 11 April , 2012 Author Share Posted 11 April , 2012 Thank you Mr Hubbard. 272 miles per hour certainly brings home the devastating effect of steel on flesh. Link to comment Share on other sites More sharing options...
punjab612 Posted 11 April , 2012 Share Posted 11 April , 2012 Thank you Mr Hubbard. 272 miles per hour certainly brings home the devastating effect of steel on flesh. Or lead in the case of shrapnel Peter Link to comment Share on other sites More sharing options...
David B Posted 11 April , 2012 Share Posted 11 April , 2012 At that speed you would be history according to Bruce. Link to comment Share on other sites More sharing options...
Retlaw Posted 11 April , 2012 Share Posted 11 April , 2012 Or lead in the case of shrapnel Peter Shells are made of Cast Iron, the contents can be any thing from lead balls, to bits of scrap metal, it also depends on the explosive used, different explosives have different burning rates. Retlaw. Link to comment Share on other sites More sharing options...
centurion Posted 11 April , 2012 Share Posted 11 April , 2012 Would it not depend on the type of shell? Yes and the type of gun and, if shrapnel, the range for which the fuse was set. Shrapnel effectively travels at about the same speed as the shell from which it is ejected and this depends on many variables. Shrapnel balls take their velocity from the shell bur will loose it faster once ejected so the size and weight of the shrapnel ball is also relevant Shell fragments on the other hand are propelled by the force of the explosive in the shell so can be to some extent independent of the speed of the shell. Fragments from a bomb lobbed from a catapult will bethe same speed in practical terms just the same as those from the same type of shell fired from a gun so in this case the design of the shell and the explosive used will determine the speed of the fragments, No one size fits all answer. Link to comment Share on other sites More sharing options...
nigelfe Posted 12 April , 2012 Share Posted 12 April , 2012 Ah, the usual state of confusion I see. This is why its important to use the correct terminology. Shrapnel, projected forwards through the nose of the fuze is relatively slow moving. Its velocity is the combination of the carrier shell terminal velocity and the velocity imparted by the small gunpowder charge used to eject the bullets. Velocity was quite low but the bullet weight meant it was effective up to about 300 yards. Fragments from a HE shell burst are a different matter altogether. Calling these shrapnel is technically incorrect. The starting point for their velocity is the detonation speed of the high explosive, this sets the upper limit, Lydite & TNT were about 7000 m/s, Amatol 80/20 about 5000 m/s. Obviously not all of this velocity is transfered to the fragment when the shockwave shatters the shell casing. These fragments are ragged and irregular in shape so they lose velocity quite fast to air resistance. They also vary greatly in size, in WW1 primitive shell design and a low percentage by weight of HE content in a shell meant that there were far too many big fragments, although they could travel several hundred yards through the air. Link to comment Share on other sites More sharing options...
CharlieBris Posted 14 April , 2012 Share Posted 14 April , 2012 By chance I came across some values for residual projectile velocity for a 75mm Krupp M1903 field gun. The Krupp gun had a muzzle velocity around 500 m/sec. Horizontal distance from muzzle - 1000m - 377 m/sec 2000m - 310 m/sec 3000m - 274 m/sec For a shrapnel round the balls should have a distribution of velocities with the average approximated by the shell velocity before bursting. Getting hit by a 20g ball at 300 m/sec is going to spoil anyone's day. Regards, Charlie Link to comment Share on other sites More sharing options...
MikB Posted 14 April , 2012 Share Posted 14 April , 2012 By chance I came across some values for residual projectile velocity for a 75mm Krupp M1903 field gun. The Krupp gun had a muzzle velocity around 500 m/sec. Horizontal distance from muzzle - 1000m - 377 m/sec 2000m - 310 m/sec 3000m - 274 m/sec For a shrapnel round the balls should have a distribution of velocities with the average approximated by the shell velocity before bursting. Getting hit by a 20g ball at 300 m/sec is going to spoil anyone's day. Regards, Charlie That makes a good deal more sense than some of the earlier postings (including mine), because the 6000 yards the Wiki entry is based on is a pretty unrealistic range for shrapnel rounds from a gun of around 3" calibre. Most of the field guns of the major participants had broadly similar performance to these details above, and 2 or 3,000 yards was the practical range for direct fire with shrapnel. At such distances the velocities of shrapnel balls would be in the transsonic range and energy more than a dozen times greater than at 6000. Should've spotted that sooner! Regards, MikB Link to comment Share on other sites More sharing options...
TonyE Posted 14 April , 2012 Share Posted 14 April , 2012 ......For a shrapnel round the balls should have a distribution of velocities with the average approximated by the shell velocity before bursting...... Regards, Charlie Surely that only applies if the shrapnel shell burst like an HE round and the shrapnel balls were dispensed in a spherical pattern? This was not the case though, the expelling charge was at the base of the shell and all the balls were fired forward in a "shotgun" pattern; the shell body itself did not rupture. In that case the velocity of the balls would be the 300m/sec of the shell plus the velocity imparted by the expelling charge, usually reckoned to be about 200m/sec. to give a striking velocity of around 500 m/sec. Regards TonyE Link to comment Share on other sites More sharing options...
CharlieBris Posted 14 April , 2012 Share Posted 14 April , 2012 The Wikipedia article quotes a velocity of shrapnel balls as 150-200 fps (50-60 m/sec) - I would have thought it would take a fairly substantial charge to expel the balls at 200 m/sec. I should point out that the Krupp M03 and the similar FK 96 n.A had a max. range of around 5000m - both gun had max. elevations of +17 deg. The French 75mm Mle 1897 and British 18 Pounder could both outrange the Krupp guns by at least 1500m. Regards, Charlie Link to comment Share on other sites More sharing options...
PhilB Posted 14 April , 2012 Share Posted 14 April , 2012 With the speed of sound being about 343m/s or 1126 ft/s, there must have been an awful lot of stuff travelling supersonically - and presumably lots of sonic bangs? Though how you`d sort a sonic from a normal bang might be tricky! Link to comment Share on other sites More sharing options...
TonyE Posted 14 April , 2012 Share Posted 14 April , 2012 The Wikipedia article quotes a velocity of shrapnel balls as 150-200 fps (50-60 m/sec) - I would have thought it would take a fairly substantial charge to expel the balls at 200 m/sec..... Regards, Charlie Sorry, my typo and getting my units mixed! I did indeed mean 200 fps. Although I quite happily use Metric for most things in everyday life, for ballistics I am still stuck in an Imperial mind set! Going back to my post and using more than the fingers on one hand it should have given a striking velocity of 300+60 m/sec! Apologies TonyE Link to comment Share on other sites More sharing options...
nigelfe Posted 15 April , 2012 Share Posted 15 April , 2012 Pre-WW1 the French experimented and determined that 58 ftlbs was the energy required to kill a man. IIRC they did their research with horses. A shrapnel bullet was designed to deliver this energy. WW2 research revealed that the necessary energy was a lot less than this. However, the mass of the shrapnel bullet meant it held the necessary energy for up to 300 yds ('carrying power') whereas small fragments from HE shells were only effective up to about 30 yds, bigger fragments were obviously effective at greater distances. I don't generally deal with shrapnel, but this page http://nigelef.tripod.com/wt_of_fire.htm of my web site does deal with the matter and provides some numbers. Link to comment Share on other sites More sharing options...
Retlaw Posted 18 April , 2012 Share Posted 18 April , 2012 Surely that only applies if the shrapnel shell burst like an HE round and the shrapnel balls were dispensed in a spherical pattern? This was not the case though, the expelling charge was at the base of the shell and all the balls were fired forward in a "shotgun" pattern; the shell body itself did not rupture. In that case the velocity of the balls would be the 300m/sec of the shell plus the velocity imparted by the expelling charge, usually reckoned to be about 200m/sec. to give a striking velocity of around 500 m/sec. Regards TonyE Don't think the velocity of the shell comes into it, . 303 machine gun rounds have no greater velocity when fired from a diving Spitfire, than .303 rounds fired from a Rifle, Lewis, or a Vickers in a static position. Retlaw. Link to comment Share on other sites More sharing options...
nigelfe Posted 19 April , 2012 Share Posted 19 April , 2012 Sorry mate, you're wrong. The firing device and projectile each have independent velocities, if they are both travelling in exactly the same direction then the actual projectile velocity is the sum of the two, if the directions of travel are different then its a vector sum (which is what happens with fragments from bursting shells although they may be slowed a lot by impact). Muzzle velocities are always expressed for a stationary firing device. Link to comment Share on other sites More sharing options...
ianjonesncl Posted 19 April , 2012 Share Posted 19 April , 2012 However, the mass of the shrapnel bullet meant it held the necessary energy for up to 300 yds ('carrying power') whereas small fragments from HE shells were only effective up to about 30 . Nigel Are those distances effectively "safe splinter distance" ? or "Lethal Splinter Distance" Appreciate I am mixing modern terminology with WW1. Ian Link to comment Share on other sites More sharing options...
Ogilwy Posted 20 April , 2012 Share Posted 20 April , 2012 Having just spoken to the people at work who design and proof test shells their ball park answer is the speed of the fragments will be slightly less than the Velocity of Detonation (Vof D) of the main filling. Therefore if you know the V of D of say Picrite or TNT the shell fragments will be close to that on the slower side! What was also discussed was that the fragmentation and fragmentation pattern from that period would and is very irregular and as a result the leathal effective distance from the burst point will be very much reduced from what we would know nowadays. I shall talk to some of our scientists later and get you the V of D for TNT and some of the common fillings. Rod Link to comment Share on other sites More sharing options...
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