Wire Cutting Shells

[PhilB]

I read that neither HE nor shrapnel shells were effective in cutting barbed wire. The navy had long experience of specialized shells for cutting rigging and spars. Did the army experiment at all with shells specifically designed to cut wire? Phil B

[Hoplophile]

Experiments were conducted throughout the war to determine various ways of cutting wire. At times, moreover, these experiments yielded effective techniques for cutting wire. The difficulty, however, was that 'wire' was a rapidly evolving phenomenon. Thus, the technique (18-pdr shrapnel shells fired at relatively close range) that worked well at Neuve Chapelle (10 March 1915) did not work nearly as well two months later at Aubers Ridge (9 May 1915.) The chief reason for this was the fact that the Germans used a much thicker grade of wire.

The problem was further complicated by such factors as the way that wire was supported (wooden stakes, metal stakes, twisted metal stakes), the conditions of the ground (which had an effect on many kinds of fuzes) and quality-control in the manufacture of fuzes.

[Gunner Bailey]

Another problem was that most experiments were made with British wire. German wire was generally a heavier gauge and none of the experiments were fully valid.

Gunner Bailey

[PhilB]

So there never was a shell effective at cutting German wire? Phil B

[bmac]

So there never was a shell effective at cutting German wire? Phil B

A series of tests were conducted using the 72nd Battery RFA against different formats of German wire and trenches at Calais in November 1915. Three types of shell were used:

Timed shrapnel

HE burst on impact

HE delayed action

Timed shrapnel was found to be the only means of cutting the wire.

Range was found to be crucial with 2,700 yards appearing to be the maximum to give the best results. Over 3,000 yards and the results were negligible.

GHQ issued Artillery Notes Number 5 in June 1916 which discussed the various methods of wire cutting with tests that showed the 2" mortar with the Newton fuze to be very effective at wire cutting but this was a highly vulnerable, short range, front-line weapon and could not be relied upon to cut wire.

This gave detailed instructions about the use of 18pdr shrapnel for wire cutting with recommendations on range (1,800-2,400 yards), positioning of FOOs for shot correction, overhauling and calibrating of guns and the most effective location for the shell to burst, i.e. front edge of the wire, four feet off the ground. An error of just five yards meant the shrapnel would be ineffective.

A fuller version of these trials can be found in my book!

In 1917 the introduction of the Fuze 106 (instantaneous graze), which burst on immediate impact gave the field guns an alternative to shrapnel for wire cutting. It would burst on contact with the wire sending splinters out which cut the surrounding wire. This meant that the 4.5" howitzers could also be used to cut wire.

[PhilB]

Thanks, bmac. The shrapnel shells were packed with normal balls, not specialized wire cutting missiles? A small round ball doesn`t seem the ideal thing for cutting wire? Phil B

[bmac]

These numbers relate to a German 77mm shrapnel shell but I would guess that there isn't a very great difference. A low exploding 77mm shrapnel shell sent its contents, 300 ten gram balls, in a cone at a speed of 900 feet per second. The British Hadfield helmet was designed to withstand an impact at 750 feet per second. I would assume, therefore, that these balls, fired correctly and sweeping forward, would cut through a lot of wire and their supports especially as the fragments of the casing, the nose cone and base plate would also be spread amongst the balls.

[PhilB]

From what I`ve seen of detonated shrapnel shells, the case didn`t break into many pieces. I imagine it was designed that way so that the contents would emerge forwards? That means only 3 parts accompanying the balls - nose cone, baseplate and body. And only the nose & base plate would be projected forwards at high speed, the body being retarded by the explosion at the target. So the primary destroyers of wire would have to be the balls. Was a round ball effective at breaking flexible wire? It seems a quite different proposition to hitting a more or less fixed , effectively flat, steel helmet. Phil B

[bmac]

Clearly not perfect but the best available.

[squirrel]

Would there have been a difference between the effectiveness of German shrapnel shells using iron balls and the British using lead balls?

[Simon R]

The British Hadfield helmet was designed to withstand an impact at 750 feet per second. I would assume, therefore, that these balls, fired correctly and sweeping forward, would cut through a lot of wire and their supports especially as the fragments of the casing, the nose cone and base plate would also be spread amongst the balls.

Was wire made from manganese steel like the Brodie?

If it was, does this make it 'armoured wire'?

[Old Tom]

Hello,

Have been intrigued by the use of shrapnel to cut wire for a long time and was aware that tests had been carried out. Thanks to bmac for the detail. I have a note, probably from Hogg and Thurston's Brit Arty Weapons and Ammo 14-18 (I'm not precisely methodical) that the 18 pounder shrapnel had 375 balls at 41 balls to the lb. i.e. less than half and ounce each but quite a concentrated shower if the range and timing were correct. That's only about 9 lbs of shrapnel so presumably the fuse and case contributed another 9 lbs or so. Does anyone have any detail of the angle of the cone of shrapnel that was achieved just after burst.

Old Tom

[Hoplophile]

H.A. Bethel's 'Modern Guns and Gunnery' has lots of information about the behaviour of shrapnel shells, with discussions of the relativel advantages of various kinds of shrapnel balls.

Also, when discussing wire cutting, we shouldn't forget the French. The French 75mm guns fired a shrapnel shell that was lighter than that of the 18-pounder, but which flew a bit faster along a somewhat flatter trajectory. I don't have details, but I've run into lots of accounts where French 75mm guns firing shrapnel were able to create gaps in German wire obstacles.

[bkristof]

I believe there were several 'anti wire' weapons on the allied side.

But none very effective.

As far as I know the 'toffee aplle' or 2 inch stokes and the Vickers mortar (the lolly shaped projectiles) were developed against barbed wire.

Also the French already had the M1913 !!! (yes) grenade contre barbelé, a special grenade used against wire.

And do not forget, a British invention, the Bangalore Torpedo M1912!!

see: bangalore torpedo

I hope I added some info