Artillery shell fuses

My great-uncle that raised me was an artillery man in WW2, but unfortunately he died when I was rather young and I was not mature enough to ask intelligent questions of his military experiences, but now that I've found this forum perhaps I've matured enough to ask some now!

I've seen examples of artillery shells, but I've never known how the timing of the fuses is actually initiated? From what I can tell they typically screw into the front of the shell so there is no "hard wiring" so to speak, is it merely the initial shock from the ignition of the primer that starts the timer running, or some other means?

I apologize if I'm not being clear but hopefully those ordnance experts in here have heard this question from enough newbs before that they can interpret it.

Thanx for all input.

Jeff

 

Timing is initiated by being fired from the gun, generally by rotation -thus preventing accidental initiation by mishandling such as dropping or rolling shells on the ground. There are two commonly used timed devices combustion and mechanical, Combustion is fairly obvious a fuse of a given length- which is set by shortening before firing is initiated by the sudden acceleration of firing and burn down to the exploder pellet which sets off the main charge. They are suscepable to air pressure, and moisture.
Mechanical fuses are clockwork and run by either a spring or by the rotation of the shell in flight. The classic fuse has setting rings on the fuse to set the time manually some shells particuliary A\A have drivers to set the fuse prior to loading, the gun loaders push the shell with its fuse in place into the setter and the device sets the fuse to the correct setting and releases the round to be loaded -some guns for example the US 90mm M2 had an intergal system the loaders presented the round to the open breech and the shell was automatically set and rammed. Similar systems were used on British guns for example the 3.7in and in the German 105mm and 128mm guns.

There are momentary delay fuses which give a delay of 0.1 to 0.2sec. This is done not by the primer but a secondary fuse, sometimes called a graze fuse, its striker flies forward due to deceleration on impact and initiating the exploder. In US shells like the 75mm M48 the impact detonation is turned off by preventing the flash of the fuse element passing to the exploder by blocking the central tube of the fuse with a shutter. The British used a similar system but a cap was screwed on the impact fuse to prevent it working. For short delay of 0.15sec German fuses used a system diverting the impact fuse flash down a tube filled with a delay action powder.

The above applies to classic fuse systems, do doubt modern proximity micro-electronic systems have replaced timed mechanical systems. Impact systems probably remain the same as they were simple and reliable.

Steve

 

Nice post, razin!

 

well I know that the american howitzer shells were fitted with special fuse so they could penatrate 6 feet of concrete

 

Thanks Razin! I knew someone in here would know the answer!

 

well I study this kind of stuff alot

 

It depends. There are a number of types of fuzes for shells

Point detonating: This is a fuze on the front end of the shell. Impact on the target sets it off. These come in several variants including: Graze or "All ways" fuzes that initate detonation if the shell strikes anything solid whether the fuze impacts the surface or not. Stand off. These have a rod sticking out the front of the shell to allow it to detonate while still not in contact with the impact surface. Delay. Unusual for a point shell but possible. These will initate the fuze but a slight delay ensues to allow the shell to bury itself into the target surface.
Another variant associated with HEAT rounds is the piezo-electric fuze. This uses the pressure of impact to generate an electrical charge that is transmitted from the point detonation part of the fuze to the base portion that actually sets the round off. This is necessary for proper formation of the jet blast that HEAT rounds produce.
Point detonating fuzes are normally in the nose of the shell.

Base detonating: These are most common on armor piercing (APHE) or heavy wall HE (SAP) shells. They initate like the point detonating fuzes do but normally incorporate a delay to allow the shell to penetrate the target first before detonating. Base detonating fuzes are normally at the rear / back / base of the shell.
A variant of the base detonating fuze that acts like a point fuze is found in HESH rounds. Here the round impacts the target and collapses against it like a bug on a windshield. The fuze impacts last and sets the round off.

Time fuzes. These generally are in the nose of the shell. They consist of a fixed and movable portion. The movable protion is rotated to form a longer or shorter labyrinth path for the fuze train to act. That is, by rotating the fuze movable portion you can vary the time it takes to detonate. Time fuzes of this sort initate when the gun is fired by either rotation or inerta or both.
These are generally used with antiaircraft guns, when firing air bursts, or using shrapnel / case rounds.

VT or proximity fuzes. These use a small transmitter to tell the fuze when the target is within lethal damage distance. Activation is done by inerta on firing normally.

Older pre- 20th century fuzes often used the flame / blast of the powder in the cannon to initate fuzes. This was common up to just prior to the 20th century when better fuzing was developed.

 

well thats all I really know about artillery

 

And thanks for expounding on this, TA G.

 

no sometimes I think manpower and stategy won the war

 

Oh really?

Nice posts from Razin and T.A. Gardner, by the way.

 

I assume your comment was spurred by my signature line. Uh, I don't think any one line answers that question. The following is where I believe the quote in my sig originally came from:

 

Paratrooper, calm down old son.

You are entitled to ask questions and give comments as are anybody else on here mate.

The members on this forum are a little different to games forums although some habit those also. And its no insult to games forums.

But this is a forum on ww2 generally and the visitors here tend to be quite knowledgeable and extremely helpfull.

Your going at a gallop. No one on here wants to admonish a new and younger member.
Well not until they get their intelligence questioned.

Some of the guys you've battered your horns into will usually go out of their way to help you with any info and provide you with stuff..

Dont demand it. You wouldnt go into the library and stand in the middle of floor and shout SHERMANS...TELL ME ABOUT IT.... Well you might, if you do can you get a mate to cam it on phone and send it in.

Relax, pull up a chair and ask.

 

Oh and signature at bottom of messages...its not code, its not for you personally. They are just things that mean something to the writer.

So dont drop your rattle on me theres a good fellow.

Youll get a lot out of this site if you slow down mate.

 

okay well I was just trying to kind of get a point across