A 155-mm artillery shell ends its life with a spectacular explosion. We decided to take a look at the place where its story begins.

First impression – it’s loud! Spindles of machine tools spin at several thousand revolutions per minute, automatic lathes change tools, and cooling emulsion constantly flows over manufactured components. Some machines turn, some mill, and others drill. They are all producing pieces that will soon create artillery ammunition.

“Take a look at that,” says Tomasz Serafin, Head of the Machining Department at Dezamet Metal Works (Zakłady Metalowe Dezamet), placing a small object in the palm of his hand. It looks like a button or a rivet and is a few millimeters in diameter. “It’s an alignment pin,” explains the engineer. “One of the 57 components of the fuse for a 155-mm artillery shell.” I pick up the part and turn it over in my hand. I find it hard to believe that something so inconspicuous could be so important. Without the pin, the mechanism could not be assembled properly, and without a functional fuse, the shell would be nothing more than a steel casing filled with explosive material.

Ammunition is most often discussed in statistical terms, using large numbers and estimating stockpiles or consumption in the millions. Countries are competing to announce increases in production, armies are counting their stocks, and politicians are announcing new investments. In such discussions, it is easy to forget that every shell is the sum of dozens of meticulously crafted parts, hundreds of technological operations, and arduous work of anonymous people. We decided to take a closer look and shed some light on the process of creating NATO’s primary artillery ammunition – the aforementioned 155-mm shell.

It All Starts with a Metal Bar

One thing needs to be clarified right away. The plant in Nowa Dęba that I visited does not manufacture the entire shell from start to finish. It receives bodies and some components of the projectiles produced by subcontractors, and manufactures, among other things, fuses and gas generators. Afterwards, all the components are assembled into complete ammunition.

One of the most complex parts manufactured at Dezamet is the housing for the safety and arming mechanism of the fuse. “This is what it looks like,” says Tomasz Serafin, handing me an aluminum part not much larger than a matchbox. He then shows me a technical drawing that illustrates the scale of the challenge. On this small part, the designers have specified 75 dimensions relating to surfaces, holes, threads, and other geometric features. All of these must fall within strictly defined parameters, even though the entire part is produced in a single operation on a numerically controlled lathe.

At first glance, all machine tools look alike. Steel and aluminum bars disappear one after another behind transparent covers, only to emerge a moment later as finished parts. Tomasz Serafin encourages me to take a closer look at one of the machines. What makes it unique is that it is integrated with a tool inventory consisting of as many as eighty milling cutters, drills, reamers, lathe tools, and other bits, selected by the machine’s control program. The more complex the part, the more frequently the machine switches between tools. The operators no longer manually guide the cutter across the material. Instead, they prepare the program, monitor the process, and inspect the finished product. The machine does the rest.

Just a quarter of a century ago, things looked completely different. A single part had to be moved from one lathe to another and from one milling machine to another. Each operation required a separate machine setup and a separate mounting of the piece, while time just kept ticking away. Today, the entire process takes 12 to 14 minutes. Using conventional machine tools, producing the same part would take at least an hour and require several dozen separate operations.

Where the Machine Stops

Watching the machines at work, it is easy to conclude that modern ammunition production is almost entirely automated. That illusion disappears a few dozen meters further, in a hall where the monotonous hum of the spindles is no longer audible. On the tables lie the same parts that have just come off the machine tools. Theoretically finished.

“This is where we perform deburring,” explains my guide. It involves manually removing burrs and sharp edges that may remain after turning, milling or threading. Sometimes they are almost invisible, but just one is enough to prevent a component from operating as smoothly as it should during assembly. That is why every part, even the tiniest one, passes through the hands of a worker equipped with a file, scraper, reamer, or countersink. Most of the staff here are women, and they are doing a truly meticulous, watchmaker-like job, delicately running files along the edges of parts smaller than a coin.

Next, the fuse parts go to the washer. The enclosed machine looks more like an industrial washing machine than an element of an ammunition production line. The freshly manufactured pieces are placed in a basket that rotates in a tetrachloroethylene bath for about 15 minutes. This is the final stage of cleaning before quality control – residues of cooling emulsion, metal shavings, and any contaminants that could hinder subsequent assembly must be removed from the surfaces. After washing, the components are sent to the measurement laboratory. If the inspection confirms compliance with the documentation, they can proceed to the next stage of their journey through the factory.

Where Small Parts Become a Mechanism

The fuse assembly department – commonly referred to as the “fuse shop” – resembles a laboratory more than a production hall. Long tables are lined with containers filled with dozens of small components. The assemblers – once again, mostly women – work with tweezers, precision screwdrivers, and inspection tools, using small assembly presses, magnifying glasses and other magnifying devices. Instead of the roar of machine tools, all that can be heard is the quiet clatter of parts placed on the tables and brief conversations among the workers.

Assembly is carried out in work cells. Each team is responsible for a specific stage of the assembly process, after which the finished subassembly moves on to the next station. Step by step, the mechanism takes shape. “Here we insert the heart of the fuse,” says Wojciech Żmuda, Head of the Assembly Department, which includes the fuse shop and the paint shop, as he approaches one of the tables. The heart turns out to be a rotor that, upon firing, rotates into the correct position and determines how the fuse operates. Depending on the way it is set by the artilleryman just before firing, the projectile can explode immediately upon impact or with a short delay. Two operating modes, one small component, and precision, as there is no room for chance here.

However, at this stage, the fuse is still not a finished mechanism. Metal parts are assembled, but there are no pyrotechnic materials yet. Those will be added later, at a different workstation and under different safety conditions. “We don’t install the activator on this floor,” explains Wojciech Żmuda. The reason is simple. The building has strict restrictions regarding the amount of explosives that can be present at workstations at one time. Therefore, the final stage of assembly takes place in specially prepared enclosures, designed in such a way that, in the event of a failure, the effects of a potential explosion are directed away from the work area.

Explosion-Proof Plant

It is only when we step outside that I begin to understand that the same logic was applied when designing the entire plant. Tall concrete structures, positioned at an angle, rise between the buildings. “These are retaining walls,” says Wojciech Żmuda. “They are inclined for a reason. If there was an explosion, they would absorb some of the energy from the blast and direct the shock wave upward, rather than allowing it to spread horizontally between the buildings.”

Later, I realize that the retaining walls are merely the most visible piece of a much larger puzzle. The buildings are scattered across the plant’s grounds to minimize the effects of a potential explosion as much as possible. The halls where explosive materials are handled are covered with lightweight roofs, designed to give way first in the event of an explosion and direct the energy upward. Moreover, the floor beneath our feet is antistatic, and the entire facility is protected by an extensive lightning protection system. Here, safety is not an addition to the production process, but one of its fundamental elements.

When Parts Become a Whole

Let’s return, however, to the production of the shell. This is the first time I see it as a whole –in the paint shop, where the steel bodies are coated with paint. It’s a peculiar sight. Suspended from the conveyor hooks, the shells slowly move through the hall like carcasses in a slaughterhouse. Their journey through the paint shop begins with a thorough washing and degreasing of the surface. Next, workers mask off the copper driving bands and other components that should not be painted. That is the moment the painter gets to work. Dressed in protective coveralls, with a spray gun in hand, he evenly applies layers of paint. It is not just a matter of aesthetics. The coating is designed to protect the steel body from corrosion during many years of storage, transport and operation.

The painted projectiles are sent to the drying room. “This isn’t an ordinary dryer,” points out my guide. “The radiators apply heat directly to the shell body, and not the air around it.” After about 40 minutes, when the paint is cured, the protective covers can be removed from the driving bands, which are then painted the required color, the fuse cover is installed, and identification markings are applied. After all these operations are complete, the finished missile is placed on a pallet, and set off to the warehouse.

The color is not a matter of aesthetics either. “Green means high-explosive ammunition,” explains the head of the paint shop. “Blue is for training ammunition, orange for experimental and research products.” I nod to show I understand. Two hours earlier, I was looking at a steel alignment pin lying in the palm of my hand. Later an aluminum housing of the safety and arming mechanism, springs shorter than my little finger, a rotor that the workers call the ‘heart of the fuse,’ and finally, a finished mechanism enclosed within a steel body. Now a complete shell is standing before me – a green one, so in its most dangerous combat variant.