Safety First: Industrial Safety in 1632, Part Two, Technical Aspects

Ambrose Bierce, in The Devil’s Dictionary, defined an “accident” as “an inevitable occurrence due to the action of immutable natural laws.” But some industrial accidents are avoidable, and the secret to minimizing them is to know what the hazards of the job are, and to reduce those hazards by a combination of engineering controls (e.g., safer machinery), administrative controls (e.g., worker training), and personal protective equipment.

As a result of the Ring of Fire, the Industrial Revolution is starting at least a century ahead of schedule, and will occur at a much accelerated pace. This will dramatically increase the risk of workplace accidents and occupational diseases. Fortunately, the up-timers can also educate the down-timers as to how to improve occupational safety.

Hazard Monitoring

We need to have ways of quantifying conditions in order to determine which workplaces are unsafe, and how good a particular safety technology is at mediating the hazard. (A hazard measuring device, when coupled to some kind of signaling means, becomes a warning device.)

Heat and Cold. Simple thermometers are already known (in 1629, Delmedigo described a sealed glass thermometer with brandy as the expandable liquid), and temperature scales appeared by 1613) but as of the RoF, scales weren’t standardized, and the thermometers were pressure sensitive. These problems will be solved quickly.

Humidity. Crude hygrometers were known before the RoF. Two thermometers, one with a wet bulb and the other a dry bulb, can be combined to make a hygrometer.

Air movement. The modern cup anemometer is a simple mechanical design and should be duplicated fairly quickly. In fact, I think I put one into “Stretching Out, part 4.”

Dust. Collect dust on filter, then weigh.

Noxious gases. Quantitative gas analyzers are largely beyond early post-RoF capabilities. We are essentially back to the “miner’s canary” level of monitoring. Old mining books speak of detecting “fire damp” (mixture of methane and air) by observation of how it affects the operation of the Davy “safety lamp”; of “white damp” (carbon monoxide) by brightening of the flame of an ordinary lamp; “black damp” (carbon dioxide) by the reduction of such a flame, or by reaction with lime water or litmus paper; and “stink damp” (hydrogen sulfide) by its smell. (Treatise on Coal Mining, 1900).

Noise. Most common sound measuring devices measure the pressure exerted by a sound and convert it into an electrical signal. I am not aware of any pre-RoF sound monitoring devices. The first practical device was the carbon button microphone (1870s) connected to a current meter. These should be fairly straightforward post-RoF introductions.

There is enough up-time audio equipment in Grantville to set up a testing lab for noise protection devices. Nothing fancy; we hook up a microphone to an amplifier or other device with a VU meter. That’s our detector. Next we need a reference sound source. This might be a cassette player, with a speaker, playing a “standard” tape. We separate the speaker and mike by a “standard” distance, and check the VU meter readings with and without the test material covering the speaker. If the sound is so muffled that it doesn’t stir the meter, we can move the speaker closer and then apply the rule that the sound intensity is inversely proportional to the square of the distance.

This is not, of course, a method which would be acceptable in a modern acoustics laboratory. But it is way beyond anything the down-timers had.

Ultraviolet radiation. The ideal UV meter would be a photoelectric device, based on silicon carbide or aluminum nitride, or perhaps a gas-filled tube. Laboratory UV detectors are unlikely to be available in Grantville. Some fire detectors are sensitive to UV-B and might be adaptable to goggle testing use.

There are probably sources of UV light in Grantville. These will mostly be sources of long-wave UV, the “black light” tubes used for shows and so forth. However, rockhounds and geology classes may have short-wave UV lamps.

Next we need a detector. It could be an up-time “glow-in-the-dark” decoration. Or it could be a fluorescent mineral, from an up-time rockhound collection, or found fortuitously after the RoF. Again, it is probably easier to find materials which fluoresce strongly when exposed to long wave UV. In essence, we are looking for glasses which, interposed between the light and the fluorescent material, prevent the fluorescence by blocking the light.

Safety Assurance

Safety is assured by three different means: engineering controls, administrative controls, and personal protective equipment.

Engineering Controls

Engineering (environmental) controls are facility, process and machinery changes which reduce exposure to hazardous conditions. They can modify operating conditions so that the hazard is less likely to arise, less severe when it arises, or more quickly dispelled. Or they interpose a barrier between the worker and the hazard. Finally, they can at least give warning that a hazard has increased, so workers can don protective equipment, leave the work area, or take corrective action.

Engineering controls of the first category include

–use of safer raw materials (e.g., eschewing lead and mercury).

–wetting systems to control dust

–assuring adequate lighting, temperature control, ventilation (vents, fans, and fume hoods), and waste disposal

–designing machinery controls ergonomically to reduce repetitive stress injuries.

Barriers take several forms. First, there is the process enclosure; the potentially hazardous process is conducted inside a closed environment, so that exposure occurs only during raw material replenishment, product removal or maintenance, or if it a leak occurs. A variation on this is one in which the process is partially enclosed, and workers pass in and out of a controlled access point designed to mitigate the escape of hazardous materials into the larger environment. If the hazard is stationary, like a machine workstation, then it is sufficient to keep the worker out of harm’s way by means of a guard rail or safety interlocks.

Secondly, there is the operator enclosure; the worker is placed in a protective control room or cab.

Thirdly, there can be mobile barriers, usually linear, that can be placed in the likely propagation path of the hazard. For example, one can place heat shields, steam curtains or air jets in front of radiant heat sources.

Warning devices include leak and smoke detectors.

Engineering controls may have existed earlier (e.g., shoring up the ceiling in a mine, but they became more common in the nineteenth century: white phosphorus matches were banned in Denmark in 1872 (Emsley); machinery guards were required by Great Britain, and ten American states, by 1897 (MacLaury).


Ventilation. Natural ventilation is achieved by providing permanent openings to the outdoors, or by opening doors, windows and vents. Engineers need to worry about making these easy to open and close (especially if out of reach), and making it easy for air to pass through them (e.g., by aiming the vent or adjusting a window wing). Exhaust pipes can be equipped with deflectors to increase draft. Equipment is arranged so as not to obstruct airflow.

Artificial ventilation is designed to exhaust (or clean) contaminated air, or to bring in fresh air. It will probably involve some kind of fan and there may also be a filter to remove dust.

If the hazard is localized, an exhaust hood may be positioned above the source, an air douche may be used to blow fresh air at the exposed worker, or an air curtain can prevent air exchange between the contaminated area and the work zone proper.

Heating. Heating systems can be central or local, and will probably involve circulation of heated air, hot water or steam. These pose hazards in their own right.

Illumination. Natural illumination can be provided by windows or skylights. The introduction of a better quality of glass will increase light transmission. Natural illumination is often problematic if there is a need to control temperature. Night work indoors, of course, necessitates artificial illumination.

Artificial illumination as of RoF took the form of torches and lanterns, which in turn presented fire hazards. In OTL, subsequent developments include the gas lamp (1792), electric carbon arc (1809), limelight (1826), kerosene lamp (1853), electric filament lamp (1870s), mercury vapor lamp (1901) and fluorescent lamp (1937). Electrical illumination will require either batteries or a power generation and distribution system.

Reflectors can be used to make more efficient use of the available light sources.

Noise Reduction. Obviously, you can say that factories are already loud; if it bothers the worker, let them wear earplugs.

But the other approach is to reduce noise generation and transmission by various engineering expedients.

You start by eliminating noise at the source.Noise can be abated by use of equipment substitution (presses instead of hammers, belt drives instead of gears, “mute” plastic contacts instead of metal ones, rotating rather than reciprocating mechanisms), process substitution (non-percussive processes instead of percussive ones, welding instead of riveting), preventative maintenance (lubrication, replacement of worn-out parts), and anti-vibration design (lower rotational speeds, vibration dampers, altering the vibrating member).

If that isn’t enough, you need to reduce sound transmission (soundproofing rooms, placing individual machines in enclosures, baffling equipment). Soundproofing involves the reflection or absorption of sound. It can be done locally (a machinery enclosure) or more generally (a wall between a noisy room and the rest of the factory).

Administrative Controls

These control who performs the work, and when and how. One might think that workers would logically do the work in the safest possible way, unless required by supervisors to do otherwise, but that ignores economic realities. During the nineteenth century, payment on a piecework basis encouraged workers to adopt unsafe practices if it would speed up their work. For example, nailers didn’t wet down their cutting machines to reduce dust, because dry cutting was faster. (Sellers 26).

Administrative controls begin with screening prospective workers to make sure they have the mental and physical capacity to perform the work without special risk. The workers may have to meet minimum age or height requirements, and be free of lung or heart disease, or back trouble, or particular allergies. After hiring, they may be required to undergo periodic medical checkups to make sure that they are still fit. This surveillance will also spot deterioration of health as a result of exposure to workplace hazards, expected or unexpected.

It is important not to leave the examination to worker discretion. Even in the nineteenth century, peer pressure, as much as job competition, discouraged workers from taking time off from work because of occupational disabilities. (Sellers 23). Physicians were consulted only once the worker was seriously ill. This wasn’t just a matter of economics; the competence of doctors was questioned (24).

When the company physical was first introduced, there was considerable worker resistance. The workers believed that the exams were a subterfuge, used to “weed out union sympathizers from the workplace.” Or at the least, that the company would refuse employment to the old or infirm merely because of the “compensation risk” they posed. (119). The burden on government and industry will be to persuade workers that the examination is to their ultimate advantage. Even — or perhaps especially — when the employee is on the slippery slope of some occupational disease (24).

Once the worker is on the job, work rules (or laws) limit the number of hours worked each day, and the length and frequency of rest breaks. The employees may be rotated in and out of particularly hazardous assignments to give their bodies a chance to recover from unavoidable exposures.

Administrative controls also include worker training in how to perform the work and how to respond in an emergency, signage to remind the employees, and penalties for lapses. In a steel plant, workers might be required to drink plenty of liquids to reduce heat stress. (Given that Grantville is now in Thuringia, Germany, I suspect that the liquid imbibed will be beer, not water.)

Personal Protective Equipment (PPE)

The most obvious means of protecting workers is to armor them in some way against the hazards, whether they be physical, chemical or biological. OSHA considers this to be the final line of defense, and would prefer that the hazards be minimized by other means first.

Let’s review the issues and options, from head to toe. Before we get into the details, one caveat: don’t use this article as a guide to what is appropriate personal protective equipment in the modern workplace!


Head Protection. Soldier have worn helmets since ancient times, to protect them from inconsiderate blokes swinging maces in their direction. The “hard hat” is the construction workers’ standard head protection. The original ones, patented by Bullard in 1919, was made from steamed canvas, glue, and paint. They were called “hard boiled hats” because that is exactly how they were made. Later models were made of aluminum, fiberglass or plastic.

Hard hats consist of a hard shell and a resilient suspension. The shell helps spread the shock over a larger area, and also flexes a bit to absorb some of the impact energy. The suspension elevates the shell so it is not in direct contact with the top of the worker’s head. Since the suspension is made of an elastic material, it absorbs more of the impact, as it grudgingly compresses in response to the blow. If the shell still is forced down against the skull, at least it will be moving more slowly.

In the 1632 universe, we can certainly make hard hats. The main disadvantage is that these are likelier to be heavier and hotter than their up-time counterparts. For several years, at least, the shell will be metal, not plastic; the suspension, leather or fabric, rather than nylon.

Hard hats were one of the first up-time articles to be closely inspected by down-timers. In Douglas Jones, “Schwarza Falls” a down-timer reported to his lord: ” . . . one of the men let me try on his helmet. It was very light compared to what I expected, not metal, but something much lighter and yet harder than leather. The helmet did not rest on the head, but was supported away from the head on a clever network of straps. I feel that a blow to the helmet would not be felt directly, not with those straps in place.”


Ear Protection. Ear protection dates back to Homeric times. After all, Odysseus had his crew put wax in their ears, so they couldn’t hear the seductive song of the sirens. Ornamental earplugs, made of clay, ivory, amber, glass, and metal, are known from archaeology.

The loudness (power) of a sound is stated in decibels, compared to a reference sound level. If sound A has a level which is 10 decibels higher than sound B, then A is ten times the power. A twenty decibel difference would imply that A was one hundred times the power. And so on. If the threshold of human hearing is called zero decibels, then a sound which is 70 decibels, or louder, is capable of causing harm, at least after prolonged exposure. According to EPA and NIOSH, safe exposure is limited to 24 hours at 70 decibels, 8 hours at 85 decibels, and 2.5 hours at 90 decibels. The acute pain threshold is 130 decibels; eardrums rupture at 190 or so decibels; 200 decibels can kill.

The sound power is proportional to the square of the sound pressure (what the monitors actually measure), so a tenfold increase in power corresponds to a 3.16-fold change in pressure. Our subjective perception of loudness is a function of intensity, duration and even frequency. A tenfold increase in power corresponds to roughly a doubling of the loudness.

By way of comparison, a vacuum cleaner at one meter produces 80 decibels, a loud factory, 90; a jackhammer at two meters, 100; a rock concert, 120; a fired rifle at one meter, 140.

The standard personal protection against industrial noise is the earplug. A cord comes in handy for pulling the plug out of the ear canal. Modern earplugs are made of foam (polyvinyl chloride or polyurethane), and reduce noise levels by 25 decibels. A heavier-duty alternative is the around-the-ear acoustic earmuff, with additional sound-attenuating material.

Foam isn’t going to be readily available (until we restart the plastics or rubber industry), but cloth earmuffs should do. Again, the problem is that they are going to be bulky and hot. The ideal material is the one which provides the most sound absorption for the least weight. In general, the best materials are likely to be those which have a complex porous structure in which sound can be trapped, as it is in foam.

Most of the published data on sound absorption relates to building materials, and those are given a noise reduction coefficient (the average of the absorption coefficients at frequencies of 250, 500, 1,000 and 2,000 Hz). The frequency range of human hearing is about 20 to 20,000 Hz.


Eye Protection. Even in modern America, there are about two thousand eye injuries in the workplace every day. Sixty percent occurred to workers without any eye protection, the other forty percent to those wearing inadequate protection (usually eyeglasses without side shields).

According to a 1980 BLS study, about 70% of the accidents are caused by flying or falling objects, and about 60% of these were smaller than a pinhead. Some operations naturally produce dust or chips. Dangerous fragments can also be generated by explosions and breakage. Another 20% of the eye injuries were the result of contact with chemicals.

If the hazard is purely mechanical, then the key concerns are impact resistance and coverage. By coverage, I mean that you are protected against attack from the flank as well as the front.

With radiation, the intensity of the radiation has to be reduced to tolerable levels, without completely blocking your view of the workplace.

Safety glasses and goggles are the primary eye protection. Goggles are better because it is more difficult for the particles or chemicals to get around them. Face shields may be added to provide an outer line of defense, and also protect the face.

Any eye protection must be transparent, which pretty much limits the choice of material to glasses and plastics. Until we rebuild the plastics industry, we will have to use glass. That is unfortunate, because polycarbonate has about ten times the impact resistance of hardened glass.

Case-hardened (fully tempered) glass is ordinary soda lime glass which has been heat-treated so that the surfaces cool before the interior, the surfaces thus being forced into compression. Its missile resistance is about twice that of ordinary glass (measured as the impact velocity causing fracture). If the glass does break, it “dices” into small fragments with rounded edges.

A second kind of safety glass is wire glass, essentially, sheet glass with an internal metal mesh. It is used mostly in fire doors and the like, because the glass remains in place even when cracked by the heat of a fire.

Neither is anywhere near as good as polycarbonate. So we will have to compensate by using thicker lenses. What about “bullet-proof glass,” you ask? It is actually a laminate of glass and polycarbonate.

Testing for impact resistance is straightforward. You start with a drop test. The ANSI standard is a one inch diameter steel ball dropped at 50 inches. If it passes that test, you move up to the high mass impact test, which uses a pointed projectile weighing 500 grams, dropped from the same height. And then there is a high velocity impact test — a quarter-inch steel ball traveling at 150 feet per second.

Some types of work, such as welding, require that the lens filter incoming light. The light can be visible light, or of wavelengths shorter (ultraviolet) or longer (infrared) than those which we can see. (We will ignore X-rays in this article.)

OSHA considers ultraviolet radiation to be the most dangerous of the three radiation components, as it can burn the skin, and damage the lens of the eye. Intense visible light can dazzle the welder, resulting in dangerous errors, and retinal damage can be experienced in extreme cases. OSHA considers infrared to be the least dangerous, although it can heat the skin and subcutaneous tissues, resulting in burns.

The degree to which a filter absorbs visible light is expressed as a shade number. A SN 8 filter blocks 99.9% (all but one thousandth) of the light, while SN 15 blocks all but one-millionth of it. According to MrEclipse.Com, smoked glass has a shade number of 11.6. Its transmittance of infrared was 0.639%, near UV 0.00054%, and farther UV 0.00032%. However, the site warned that it is difficult to produce a nice, thick coating, and that it rubs off easily. In contrast, a standard Welding Filter Shade 12 had a shade number of 11.9, infrared transmittance 0.0049%, near UV.000035%, and further UV.000039%.

It may be possible for 163x glassworkers to apply a protective surface coating to smoked glass. Another possibility is to produced a strongly colored (perhaps “black”) glass.

What about the other forms of radiation? The good news is that garden variety soda lime glass is going to strongly absorb short wave UV and far infrared light (beyond two microns). The bad news is that, without modern equipment, it isn’t easy to measure just how much “invisible” radiation a given piece of glass absorbs.

There are modern safety glasses in Grantville; for example, in Nat Davis’ machine shop. (Cresswell and Washburn, When the Chips are Down, ROF1). These will be used when the down-time equivalents just aren’t safe enough, and they will also come in handy as “gold standards” for testing purposes.

There is one other approach to eye protection that I need to mention: the reflective coating. The disadvantage of absorbing light is that the energy is converted to heat, which can crack the glass. So why not silver the surface of the glass, using a coating that is just the right thickness to reduce the light to tolerable levels, while permitting the workpiece to be seen? Well, it sounds good in theory. In practice, it may be difficult to control the thickness of the film, and then to protect it from abrasion and chemical reaction. Another problem is a phenomenon called the “ultraviolet transparency of metals”; in essence, metals which reflect visible light may be quite transparent to ultraviolet light.


Nose/Lung Protection. Many industrial processes result in the emission of gases or dusts which it is dangerous to breathe in. The final line of defense against these threats is the personal respirator. One type purifies the air; the other supplies breathable air. It may be self-contained (like SCUBA for divers), or hooked up to a fixed reservoir.

Respirators will have a tight-fitting “face-piece” which at least covers the mouth and nose (quarter-mask), and may reach under the chin (half-mask) and even up to the hairline (full-facepiece). The facepiece needs to be impervious to vapors, and, if it covers the eyes, also have a “window” to see through. Modern facepieces are usually made of rubber, plastic or silicone. However, in the 1632 universe, we may need to make do with leather, or some kind of coated cloth.

Respirators intended to fend off dust will have some kind of particulate filter. Absolute protection is provided if the pores are smaller than the particles. But there’s a trade off here; the smaller the pores, the less the airflow, and the more trouble it is to breathe. Most respirator filters trap particles by forcing them onto convoluted paths, on which they collide with fibers, or just settle on to them. Filters can be electrically charged to help them capture particles with the opposite charge. The most common particulate filter is a disk of “random laid, non-woven fiber material.” In essence, a felt (which people have made since 6,500 BC).

Protecting against dangerous gases is trickier. The respirator needs to provide a purifying agent, which can be an adsorbent or a neutralizing agent. The most common adsorbent in current use is activated charcoal. Encyclopedia Americana says that it is “produced by heating animal bones or certain types of vegetable charcoal to temperatures of 800 to 900 oC (1470-1650 oF) in steam or carbon dioxide. This treatment results in the formation of a highly developed internal pore structure with a very large surface area . . . .” It is usually granulated. Other adsorbents include fuller’s earth (a clay), activated alumina and silica gel.

The adsorbents can be chemically treated to increase their affinity for particular gases, for example, iodine treatment to remove mercury vapor. This is not likely to be discussed much in the encyclopedias and textbooks, but it may be mentioned in the manual for a particular respirator which contains such an adsorbent.

Neutralizing agents are specific to a particular chemical threat. For example, if the worker is going to be exposed to acid gases, the respirator can be charged with sodium or potassium hydroxide, perhaps combined with lime to increase absorption.

The respirator can also provide a catalyst. Hopcalite is “a mixture of porous granules of manganese and copper oxides which speeds up the reaction between toxic carbon monoxide and oxygen to form carbon dioxide.”

The protective agent can be stored in a small cartridge, mounted directly on the facepiece, or in a larger cannister, connected to the facepiece by a tube. Cannisters can be chin-, front- or back-mounted. The higher the concentration of the gas, the more likely it is that you will need a cannister-based design.

I am not going to review air-purifying respirators, other than to say that it is in Canon that there are people with SCUBA apparatus (1633, Chaps. 29, 34).


Skin Protection. Skin may need to be protected against points and edges, flying debris, chemicals (liquid and gaseous), heat or cold.

The hands are usually the most vulnerable part of the body, since they are operating machinery or manipulating the workpieces. Gloves, mitts and the like have been used since time immemorial. To guard against slashes and punctures, chainmail comes in handy, and of course chainmail manufacture is a well-established trade in the 1630s. If you need to prevent burns or frostbite, then you need an insulated glove. Basic oven mitts and pads are readily available in Grantville. and can be copied. The most problematic threats are the chemical ones, for which the modern worker would prefer a latex glove.

Other parts of the body can also be vulnerable, and hence there will be a demand for aprons, hoods, and so forth.


Foot protection. Safety boots have a steel “toe”, as that’s where you’re most likely to drop a workpiece. Soles will at least be skid-resistant, and may contain steel to protect against puncture. For particular industries, it may be important that the boots are impervious to chemicals, or electrically insulating.

The safety boots are likely to be made, initially, of leather, although I expect that rubber would be preferred. Curiously, the 1911 EB says that wooden clogs were preferred by agricultural and forest laborers, dyers, bleachers, tanners, and workers in sugar factories, chemical works, provision packing warehouses, etc.


Heat protection. Heat protection can take a number of forms, such as aluminized or asbestos clothing. Asbestos, of course, presents its own hazards, and aluminum is hard to come by. We will probably be making do with wool, possibly wetted down.


Fall protection. “Schwarza Falls” also mentioned the use of “safety ropes” to arrest a fall. Some up-timers should be familiar with modern safety harnesses for building construction and maintenance.


Miscellaneous. Just in case you need to be rescued, it’s prudent to be wearing conspicuous clothing. In “Schwarza Falls”, guard officer Franz Saalfelder reported that each of the three up-timers he met on May 19, 1631 (Julian) was wearing “a yellow helmet and an orange vest; the orange color was unnaturally bright.”

Summary Table

The following table summarizes typical hazards and the corresponding safeguards.



dust and noxious gases

dust control in machinery design, isolation of dusty or gas-producing processes, air filtration or neutralization, ventilation, respiratory protection

heat and cold

shielding of radiant sources, insulation, protective clothing, air conditioning, air douche, enforced rest in refuge


baffles, filter windows, goggles, eye rest


static and dynamic balancing of equipment; operation outside of resonance regions; frictional and viscous damping; elastic connections; shock absorbing soles


reducing noise generation; soundproofing; ear protection


guards to allow inspection without contact; emergency disconnects; first aid training; low voltage systems; distancing of naked conductors; insulation; grounding; protective equipment (dielectric gloves and boots; insulating tongs, mats); lightning protection

pressure vessels

inspection; pressure and temperature gauges; safety valve;


fire drills; fire fighters; access road to buildings; water supply; fire-resistant structures (overall and fire stops); fire exits and refuges; fire extinguisher; sprinkler systems


guards; interlocks; safety catches; screens; ergonomic controls; grounding; chip/dust collection and disposal; limits on required force; hoists; hand signals

Special Hazards

There are a number of industries which are prominent in the 1632 universe and which present special hazards which deserve discussion.

Mining Safety

The subject of mine safety was briefly addressed in Laura Runkle’s Mente et Malleo (GG2): “By 1632, there had already been several notable mining disasters. Usually the resulting [safety] rules did not involve the safety of individual miners, but rather the safety of the whole mine—drainage, ventilation, and the placement of tunnels and shafts.”

There is no doubt that this is an issue on which the Grantville miners will have a lot to say. They also have firsthand experience with uptime mine safety equipment. Grantville even has a resident mine safety engineer, Ron Koch. (DeMarce, Rudolstadt Colloquy, GG1).

Despite that expertise, by January 1635, the Grantville coal mining fraternity had already experienced its first post-RoF mine disaster. See Mark Huston, “Twenty-eight Men” (Grantville Gazette volume 10).


In seventeenth century mining, the principal threats to life would have been rock falls, and methane and coal dust explosions.

Inadequate lighting, ventilation, and temperature, noise and dust control would also have resulted in accidents and chronic health problems.

Room-and-pillar mining, in which pillars of rock are left standing to support the roof, is very old, and there would also be artificial roof supports. However, in the seventeenth century these supports would still have been made of wood, and there was no scientific method of determining the spacing or diameter of the supports. Modern miners use machines to place bolts into the roofs.

The most primitive method of detecting carbon dioxide was to take a canary underground. If the canary suffocated, it meant that ventilation was inadequate.

Ventilation initially was simply provided by (if you were lucky) digging ventilation holes. Later, furnaces were used to heat air and generate a draft. Still later fans were introduced, both above and below ground, but bear in mind that improved ventilation was not completely a blessing because the increased air movement could stir up coal dust.

Safety lamps were introduced in 1815. They were used, not just to provide light, but to detect the presence of methane (which would cause the lamp to burn brighter). However, they could cause an explosion, rather than forestall one, if the miners disassembled the lamp, removing the protective wire mesh surrounding the flame.

Primitive black powder explosives were replaced by more stable ones such as dynamite (remember, Nobel thought he was benefiting mankind).

Mines have also introduced fireproof ropes, “escape capsules,” and “self-rescuers.” The latter can convert carbon monoxide to carbon dioxide, or supply oxygen.


In Grantville, coal mining will continue to make heavy reliance on powered equipment, but operations elsewhere will be manual for some time to come, and hence will have a somewhat different spectrum of accident causes. Nonetheless, it is worth reviewing late twentieth century accident statistics.

According to the Mine Safety and Health Administration statistics for 1986-95, in coal mining, fatal injuries occurred when using or operating tools or machinery (27.6%), constructing, repairing or cleaning (23.7%), during vehicle/transportation operations (19%), while handling materials (11%); or during other activities (18.8%) (Table 4-4). The death was most often the result of fall of ground (31.7%), followed by powered haulage (23.1%), machinery (16.6%), electrical (8.2%); ignition/explosion of gas or dust (6.1%).

The leading cause of fatal injuries in modern coal mining is “fall of ground” (31.7% in 1986-95). In 1996-98, roof, rib and face falls resulted in nearly half of the underground fatalities. “Ground control” includes testing roof rock quality and providing adequate roof support, escape paths, signage so miners don’t wander into areas of unsupported roof, and fall warning devices. Small falls also cause nonfatal injuries, which can be mitigated by personal “bolter screens.”

Pillar recovery (taking out support pillars of rock as you retreat out of the mine, allowing the roof to collapse behind you) is particularly dangerous.

The second most important cause of coal mine fatalities is “powered haulage” (23.1%), the horizontal transport of workers, coal, supplies and waste by a variety of vehicles. Accidents can occur during entry, exit, operation or maintenance. Miners can be run over or pinned by the equipment.

Machinery poses the third biggest threat to life (16.6%). The risks, and preventatives, are those typical of factory machinery.

In fourth place, we have electrical (8.2%). Almost half of the electrocution deaths occur during maintenance and repair. Overhead power lines have been involved in many electrical accidents involving mobile mining equipment. Precautions could include some kind of power line proximity warning system, and simple methods of disconnecting all electrical circuits within an electrical enclosure.

While ignition or explosion of gas or dust is the cause of death most likely to result in coverage on the national news, it ranked only in fifth place (6.1%) according to the cold statistics. In part, its media prominence is because these incidents can result in multiple fatalities. It was the 1951 explosion at Orient No. 2, in West Frankfort, Illinois, that prompted the enactment of the Federal Coal Mine Safety Act.

The dangers are controlled by gas and dust monitoring, ventilating the mine to remove gas and dust, adding rock dust to inert the coal dust, eliminating ignition sources, isolating worked-out areas with seals, and placing barriers where they can intercept a blast.

The remaining causes of fatal injuries include explosives/breaking agents (2.9%), falling/rolling/sliding material (2.9%), and slip or fall of person (2%) (with 6.3% unclassified) (IIAHE, Table 4-5 and Figure 4A-4). The unclassified causes would have included exploding pressure vessels, fires not otherwise accounted for, hand tools, hoisting equipment, failure of an impoundment, and inundation.

The leading causes of nonfatal injuries were handling materials, slips/falls, and hand tools.

Coal miners are exposed to respirable dust, machinery noise, and other stresses. Not surprisingly, they suffer a variety of chronic illnesses, including coal workers’ pneumoconiosis (66%), hearing loss (20%), repetitive trauma (7%), and heart attack (2%) (IIAHE Fig. 5-1).

Chemical Plants

By December 1633 post-RoF, Magdeburg had a coal gas plant. There, coal was cooked in a furnace, producing coke, coal gas and a residue. Unlike coal, coke can be burnt with little smoke, making it useful for railroads. It also is used as a fuel and reducing agent in the blast furnaces of steel plants. The coal gas was burnt in Magdeburg as a fuel and illuminant. The residue (loosely speaking, “coal tar”) can be separated into pitch, light benzoils, and other hydrocarbon fractions.

In Chapter 2 of Eric Flint’s 1634: The Baltic War, a grate was imprudently removed from the coal chute, the gas main leading out of the coal gas plant got blocked by tar and coal dust, gas backed up into the furnace, and the coal in the furnace caught fire (as opposed to being merely charred to form coke).

The fire brigade sprayed water onto the smokestacks, trying to bring down the temperature and put out the fire. In retrospect, this was not a good idea. The water dissolved the firebrick in the reverberatory furnace, and reacted with the coal to form hydrogen and carbon monoxide. Air mixed with the coal gas, too. The result was a double explosion. Actually, a triple one; once the fire reached a shed used to store fertilizer — ammonium nitrate.

Even without an explosion, working with coke ovens can be dangerous. Because the coal is heated to at least 2000 degrees F, coke oven workers must be concerned about heat stress. The coking operation should be a closed system, but a leak can occur, exposing the operators to various noxious dusts and gases — some of which also are flammable.

The coal gas plant explosion in Magdeburg was probably the most dramatic chemical plant accident in canon, but it is not the only one. Hydrofluoric acid — possibly the nastiest of the commonplace industrial chemicals — got on the skin of one of Dr. Phil’s laborants, resulting in the emergency amputation of an arm. See Kerryn Offord, “Dr. Phil’s Family” (Grantville Gazette, Volume 10).

The number of different chemicals which might be manufactured in the USE is enormous. Hence, this discussion will be a general one.

Chemical raw materials are usually supplied as powders or liquids. The powders have to be transported to the plant in containers which minimize leakage. The containers may need to be sealed to keep out air, or even filled with nitrogen or carbon dioxide.

The contents of the individual containers must be transferred to a storage silo, and from there, to the reactor. These transfers should be performed, as much as possible, in closed systems, because each open transfer is an opportunity for release of dust. In addition, there can be a static charge buildup, which creates a risk of fire or explosion.

The preferred transfer mechanism is probably pneumatic. If that is beyond the technological capacity, then we will want to at least provide local ventilation.

Liquids will also be delivered to the plant. The most common ones are solvents (acetone, toluene, methylene chloride, isopropyl alchohol) and mineral acids (hydrochloric acid, sulfuric acid, nitric acid). The liquids will be directed into storage tanks and subsequently to the reactor.

Again, a closed system is desirable, to minimize vapor release. Ideally, the transfers are by permanent, hard-piped lines. If the operation is not of at a scale which favors dedicated lines, and pipes must be moved around depending on the chemical being produced, then there will be an opportunity for chemical release whenever lines are disconnected or reconnected.

Obviously, it is important to maintain the lines to ensure that leaks don’t develop. Also, piping connections can be shielded with jackets for further protection.

Storage tanks are preferably above ground, to make it easier to inspect them, and should have some kind of leak detector. Liquid chemicals can be transferred into the reactor by some kind of pump. A steam ejector can be used to create a vacuum in the reactor to suck in the chemical.

Chemical plants also need to handle gases, such as ammonia and chlorine. Obviously, the tanks and lines need to be impervious to the gas, and unreactive with it.

The reactor will need to be chemically resistant (e.g., glass lining), equipped with temperature controls and a sampling port, and built to withstand pressure. As a second line of defense against overpressure, the reactor will have a vent sealed with a rupture disk (probably made of graphite), and leading to a containment tank. To protect against fire, the headspace of the reactor can be filled with an inert gas, usually nitrogen or carbon dioxide.

Liquid-solid separations typically involve cakes with a large surface area, and hence there will be an opportunity for solvents to evaporate. Solvent vapor exposure can be controlled by local ventilation.

Insofar as providing chemically resistant vessels is concerned, we will want to recreate borosilicate glass (see Cooper, “In Vitro Veritas,” Grantville Gazette 5) and various steel alloys. For secure tubing, rubbers (see Cooper, “Bouncing Back,” Grantville Gazette 6) and plastics are important.

In Grantville, there is ample electricity to run electrical fans, but elsewhere, fans and pumps are likely to be steam-driven.


Coke, iron ore and limestone are fed into the blast furnace, where they are heated to over 3000°F. Either air (Bessemer process) or pure oxygen are blown through the molten iron. Dangers include intense radiant heat, spills of molten metal (which, if it comes into contact with a wet surface, causes a sudden and highly explosive release of steam), carbon monoxide generated by the furnace, noise, and unpleasant encounters with moving equipment. (USW; Burgess).

Metal Fabrication

In a foundry, molten metal is poured into a mold, and allowed to cool, creating a metal article of a desired shape. Hazards include noise, vibration, heat stress, and exposure to silica dust (from the foundry sand used to make the mold) and carbon monoxide.

Metals are machined with various cutting and grinding tools. In Virginia DeMarce’s “‘Til We Meet Again” (Grantville Gazette, Volume 4), we witness the dangers of an airborne power saw.

Then there is forging, which reforms a metal by impact or pressure. In Karen Bergstralh’s “Tool or Die” (Grantville Gazette, Volume 9), the villain is a drop forge. While being caught by the drop hammer is the most obvious hazard, forging was one of the first industries identified as posing a threat to hearing. Hammer operators can expect to experience sound levels of as much as 108-dB. (Burgess 103).


All too often, safety legislation has been prompted by tragedy. The 1911 Tringle Shirtwaist Fire, in which over 140 workers jumped to their deaths, prompted New York’s first building safety code. In the wake of the disaster, New York formed a Factory Investigating Commission, which in turn secured enactment of twenty state occupational safety and health laws.

It is true that during the first decade following the Ring of Fire, the number of industrial workers will be small compared to late nineteenth century America or Britain. However, that will change. The up-timers are making a concerted effort to raise the USE (and Sweden) to a nineteenth century economic level.

They must “gear-up” despite the fact that the educational level of the early seventeenth century USE and Sweden is substantially lower than that of the nineteenth century models. They need to do this quickly, to satisfy war needs. And the technology they are trying to recreate is one which they may know only from books, not from experience.

Accidents are inevitable. The question is what level can we tolerate without causing a reaction which endangers, not only the industrial revolution, but also the political one–the “second American Revolution.”


Legal and Social Framework; Pre-Regulation Accident Rates

Maclaury, “Government Regulation of Workers’ Safety and Health, 1877-1917,”

1911 Encyclopedia, “Labour Legislation”

Harger, Workers’ Compensation, A Brief History,

Seager, Social Insurance: A Program of Social Reform (1910), Chapters II (accident prevention) and III (compensation).

Stein, Priestly v. Fowler (1837) and the Emerging Tort of Negligence,

“Factory Laws,” Wikipedia

Gies, Life in a Medieval City (1969)

Lynch, Mining in World History

Emsley, The Shocking History of Phosphorus: A Biography of the Devil’s Element (2000).

Franco, “Ramazzini and workers’ health,” The Lancet, 354:858 (Sept. 4, 1999), online at

Murphy, Life Insurance in the United States through World War I,

Aldrich, History of Workplace Safety in the United States, 1880-1970,

US Dept Labor, The Job Safety Law of 1970: Its Passage was Perilous

John Marsh, on “Report to the Stockholders” (1925)

Book Review, of SAFETY FIRST: Technology, Labor and Business in the Building of American Work Safety, 1870-1939 MARK ALDRICH, 1997 Baltimore and London: Johns Hopkins University Press

“Scaffold,” 1911 Encyclopedia Britannica,

BOPCRIS, Browse: Factory laws and legislation

Key dates in Working Conditions, Factory Acts, Great Britain 1300-1899

Summary of Factory Acts in the 19th Century UK

Factory Legislation 1802-1878

ROSPA [Royal Society for the Prevention of Accidents] in the Twenties

(discusses the “Safety First” campaign)

Scottish mining accidents

Tuohy, Interurban Railroaders and Changing Work Conditions on the South Shore Line, 1908–1938

Innes, “Origins of the factory acts . . . ” in Landau, Law, Crime, and English Society, 1660-1830 (2002).

Sellers, Hazards of the Job: From Industrial Disease to Environmental Health Science (1997).

Hazards; Safety Technology

Poltev, Occupational Health and Safety in Manufacturing Industries (1985)(used frequently but not specifically cited)

Woodside, Environmental, Safety and Health Engineering (1997)

OSHA, Fact Sheet No. OSHA 92-03, Eye Protection in the Workplace

NIOSH, Eye Safety


Elvex, “How Strong is Polycarbonate,”

NIOSH Guide to Industrial Respiratory Protection (Sept. 1987),

Driving Standards Agency, History of the Highway Code

Cummins, The History of Road Safety

[USW] United Steelworkers Training Guides to Industry, “Safety and Health in the American Steel Industry,”

Burgess, Recognition of Health Hazards in Industry (1995)

IIAHE, “Injuries, Illnesses, and Hazardous Exposures in the Mining Industry, 1986-1995: A Surveillance Report,”


About Iver P. Cooper

Iver P. Cooper, an intellectual property law attorney, lives in Arlington, Virginia with his wife and two children. Two cats and a chinchilla rule the household with iron paws. Iver has received legal writing awards from the American Patent Law Association, the U.S. Trademark Association, and the American Society of Composers, Authors and Publishers, and is the sole author of Biotechnology and the Law, now in its twenty-something edition. He has frequently contributed both fiction and nonfiction to The Grantville Gazette.


When not writing (or trying to get an “orange blob” off his chair so he can start writing), he has been known to teach swing dancing and folk dancing, or to compete in local photo club competitions. Iver adds, “I can’t get my wife to read my fiction, but she has no trouble cashing the checks.”

Iver’s story “The Chase” is in Ring of Fire II