Clueless about W.W. 1 British artillery


#1

Found what I believe to be a English 18 pounder shrapnel shell. It has been rendered inert, leaving a double hand full of .5 inch lead balls in the otherwise empty projectile. Were these designed to explode fragmenting the projectile like a modern HE round, or was it a canister round where the fuze would break off the front allowing the lead balls to shot gun out? This it the first large British round I have had and I have no information on them other than having read some battlefield accounts of there use.


#2

They would appear to have shotgunned out. On the battle fields, even today, you can pick up plenty of complete but empty rusty casings come ploughing time. Also if you look at the casing, once the fuse has been taken off the remainder is virtually a tube. The fuse was only held on by a light thread between the cast iron casing and the brass fuse. Suggesting that was the intention. No doubt some did explode.


#3

The No.80 fuze was a time and percussion fuze with a burning powder train and at the appropriate moment it flashed down a central tube in the shell to a small charge of black powder in the base. This forced a plate forward ejecting the balls in a shotgun cone in front of the shell.

There was not enough powder in the ejecting charge to burst the shell itself.

The difference between a shrapnel shell and canister is that canister breaks open as it leaves the muzzle and so the gun acts like a shotgun. With shrapnel the shell is the “shotgun” when it reaches the target. As well as giving far greater range it means enemy trenches can be attacked due to the angle of descent of the shell.

Picture of 18 pr attached.

Regards
TonyE


#4

Thank you for the quick answers. I had found the picture you posted but will admit to being somewhat confused by the charge at the base being labeled as a bursting charge, but it still looked as if the muslin disk was like a shotgun wad to force out the balls.
Apparently this shell type was found wanting seeing that is was replaced by HE fragmentation shells. Was that replacement due to fuzes not being accurate enough to insure an airburst? Or was it due to advances in explosives and manufacturing processes?


#5

There is a big question over this type of shell. One that has occupied this forum in the past and opinions have differed.
These shells, most shells, were fired at close to extreme range. So the barrel would be pointing up at about 37 degrees or maybe more . Does the shell remain at that angle of repose throughout its entire flight because it is spinning due to the rifling or does it flip over at the top of its travel and come down nose first?
Narramore in his book Principles and Practices…cites testing big guns for range evaluation in the US (Aberdeen?). he says recovered shells which were painted showed clear signs of coming in base first over and over again.

Many of the unexploded WW1 shells I have seen on the battlegrounds show no frontal nose damage at all only sideways grazing from stones on the ground.

If this is true the shells would have discharged upwards greatly reducing their effectiveness.

This theory would explain why many shells in WW1 on both sides were duds. Plopping down into soft mud base first the shock was insufficient to trigger the detonating mechanism in the nose.

This theory is not fully proven but it does raise questions. Soldiers in memoirs report the scream of incoming shells prior to impact. My hypothosis is that an incoming shell flying nose first would not be audible, only ones coming in sideways.


#6

Oh my, the farther into this I get the murkier it becomes. And far, far more interesting, prior to this my ammunition interests have been confined mostly to U.S. military under 20 m/m with a few large caliber drill rounds for display use. Thank you for the information you have given and could you suggest a good place to start gathering information about artillery and it’s ammunition for the uninitiated?


#7

Chef

These folks cover the gamut: bocn.co.uk/vbforum/forum.php

Many posters here are frequent contributors “over there”.

A good overview of your projectile is covered here, about 3/4 of the way down the page:
cartridgecollectors.org/introtoa … toarty.htm


#8

Vince

Spin stabilized bullets and projectiles follow their trajectory. Otherwise, a howitzer projectile with a pdf would not work. Examples of projectiles that came back to earth base first were the result of extreme angles of firing, 85 degrees plus.

chef

Shrapnel projectiles expel both the fuze and the shrapnel at once. Centrifigal force causes the shrapnel to spread into a pattern. The projectile body, fuze, head, diaphragm and tube simply fall to earth and can hit at most any angle. That’s why so many are found and reconstructed.

The “muslin discs” shown on the drawing are inside the central tube and are there to keep it from filling with loose powder. The tube shown here contains powder pellets to enhance ignition of the expelling charge. Many shrapnel central tubes are empty and have but one disc of fiber or cotton at the lower end. The steel plate (diaphragm) above the black powder charge is what pushes the shrapnel out of the projectile. The drawing showing the black powder as a “bursting charge” is not accurate. It is an expelling charge.

Here’s a USN 3"/23 Shrapnel cartridge


#9

Over-stabilized bullet
i31.photobucket.com/albums/c374/ … /fig15.gif

Over-stabilized bullet on a high angle trajectory

This figure schematically shows an over-stabilized bullet on a high-angle trajectory.

An over-stabilized bullet rotates too fast and its axis tends to keep its orientation in space. The bullet´s longitudinal axis becomes incapable to follow the bending path of the trajectory. Over-stabilization is said to occur, if the angle enclosed between the bullet´s axis of form and the tangent to the trajectory (the yaw of repose) exceeds a value of approximately 10°.

Over-stabilization of a bullet is most probable, if a bullet has excessive static stability (a high value of sg and a low value for the tractability factor Go to formula) and is fired at a high angle of departure, especially when fired vertically. An over-stabilized bullet on a high-angle trajectory lands base first.

However, when firing bullets from handguns, over-stabilization is of minor importance in normal shooting situation, but must be considered when firing at high angles of elevation.

I work on ranges when I find fired artillery shells that show this phenomenon much more than you’d think it would happen. I have collected many fired shells that only had marks on one side of the body where it had landed. Some show that they hit with such gyroscopic force still spinning the projectile that they look to be sand blasted as they dug a hole sideways in the soil.
Yes, EOD has rendered them safe.


#10

Hi Rapidrob
Thanks for that example. It shows the point I was making perfectly. That must be a regular problem because all projectiles shed directional velocity quickly (as per the ballistics tables) but only loose rotational velocity comparatively slowly by comparison due to boundary air friction.


#11

I’m a retired Master Chief Gunnersmate. I have fired thousands of 5"/54 projectiles in war and training and seen some really strange things happen when a projectile strikes water/ground.
You actually can use the over stabilized projectile to your advantage by skipping the bullet off of the water as if you are throwing a flat stone. we used to use the technique to get Charlie hiding under the jungle canopy at a rivers edge or the beach.


#12

The last place we want to go is a discussion of external ballistics. But, I’m of the opinion that a bullet or projectile would have to be grossly over-stabilized to defy the physics that cause it to want to follow its’ trajectory. I doubt if you’d find that combination in a standard gun firing standard ammunition. OTOH, under-stabilization, causing a bullet or projectile to tumble, is often seen because most rifled-barrels have border-line twist rates to begin with.

JMHO

Ray


#13

Ray
have you ever seen or are you aware of the oval hole effect with rifle bullets at extreme ranges say 1000X plus?.A few years back they changed the backing boards on the target frames at Bisley to use polycarbonate sheeting from the older hessian they had used for more than a century.

On the 1200X target boards the bullets leave a very slightly oval hole. It is very slight, not visible to the eye but measurable with calipers. Its nearly always up/down in orientation so its not due to subsonic yaw although I would imagine they get that as well. The polycarbonate gives a good witness mark. I will try and find some pictures.

That could of course go both ways in terms of cause, it could be overstabilisation as described here or it could just be because the bullets are decending from the peak of their trajectory and are pointing downwards slightly.


#14

Vince

I’m a long range competition shooter. Those “oblong” bullet holes are always a hot topic among shooters and, as you’d suspect, there is not much agreement as to what causes them. The fact that it happens, usually at distances beyond 1000 yards, doesn’t happen that often, and is not consistent even among cartridges, has always led me to believe that it’s mostly the result of a bullet reaching the end of its rope, becoming unstable, and wanting to tumble. Even at the 1000 yard distance, the angle of trajectory is usually less than one degree and I doubt if you could detect that by measuring the shape of a hole. The fact that you seldom see it with cartridges using bullets, twists, and velocities compatible with the long ranges tends to support my opinions but, then, I’m only slightly predjudiced. ;)

Speaking strictly to small arms, there is a general agreement, amongst the shooters that I associate with, that you cannot over-stabilize a small caliber bullet except by resorting to ridiculous extremes. Even then, most bullets would never reach a 1000 yard target but be destroyed by the centrifical force not long after exiting the muzzle.

Opinions on ballistics are like belly buttons. Everybody has one. I regularly vist 2 or 3 shooting forums and you should see the discussions (arguements) that the mere mention of ballistics will generate. I have a favorite photo that I like to insert when things get heated.

ray


#15

With all the available high-speed camera gimmickry available these days, one would think there’s photographic proof of whatever it is y’all are talkin’ about.

[color=#0040FF]". . .bullet reaching the end of its rope,. . ."[/color]

Good one.


#16

Ray most of the cannon projectiles are over stabilized for one reason. Arming the fuze. Many fuzes have balls or levers that must be thrown outward in order for the fuze to start to arm.
I recently recovered several WWII 40 mm BOFORS projectiles that all landed on their sides,not the nose, the fuze never fired when they landed. I can take some photo’s of the projectiles and the impact marks can be clearly seen.
This phenomenon is most likely the cause of this post and the condition of the fired shell.


#17

The centrifugal forces inside any projectile is immense. I cant do the calculation for a cannon shell so I will do it for a rifle bullet.
A 7.62 round fired at 3400 fps from a 1 in 12 barrel is spinning at 3400 revs per second. Thats 204,000 rpm. That goes up to 350,000 rpm for a 40grain bullet from a .22-250 with a 1 in 8 twist. No wonder as Ray said they can just come apart.

But the old cannon shells we started talking about are 100 years old (all but). The development jumped forward by a huge amount in the years immediately prior to WW1.

The design criteria must have been very much scratch your head and see what looks right on the drawing board. I find it strange if they are still having the same problems today with all the computer aided design .


#18

The old guns like the 3"/23 didn’t do too bad either. The twist was on the order of 1 in 30 and the mv about 1650 fps. You do the math.

More modern guns had barrels with twists around 1 in 20 to 1 in 25 with velocities approaching 3000 fps. Even the 16" guns on the Iowa Class BBs had 1 in 25 twists at 2600 fps. That calculates to a lot of RPMs.

Of course, today, we have the APFSD which do not need rifleing. I don’t know how fast they spin.

Ray


#19

[quote=“RayMeketa”]The old guns like the 3"/23 didn’t do too bad either. The twist was on the order of 1 in 30 and the mv about 1650 fps. You do the math.

More modern guns had barrels with twists around 1 in 20 to 1 in 25 with velocities approaching 3000 fps. Even the 16" guns on the Iowa Class BBs had 1 in 25 twists at 2600 fps. That calculates to a lot of RPMs.

Of course, today, we have the APFSD which do not need rifleing. I don’t know how fast they spin.

Ray[/quote]

The guns on HMS Belfast, now moored in the centre of London had a range of 24miles. Thats just about far enough to drop one into my back yard or Falcon’s. Perish the thought! but if they ever do, I will let you know which way up they land. Good topic guys I have enjoyed it.

Vince


#20

I just had a look on google maps. I am around 12 miles from HMS Belfast as the crow flies, so the guns would have no problem with the range.

Last time I went for a look round HMS Belfest, there was a map on the turret wall saying where the turret was trained. It was the first service station (rest stop to US members) on the M1 Motorway which runs North from London to Leeds.