Experience and calculation: how engineering learned to use science, and what it means for technical businesses

For most of history, engineering ran ahead of science. Builders raised cathedrals, dug canals, smelted iron and built steam engines long before anyone could explain why their methods worked. Knowledge passed from master to apprentice, refined by trial and, too often, by failure. Rules of thumb that had worked before were used again, and margins were generous because nobody could say exactly how much was enough.

During the nineteenth century, that relationship began to reverse. In some fields, most clearly electrical engineering, products and whole industries were built outward from laboratory science rather than from craft tradition. Engineering schools teaching mathematics and physics spread, and the ability to calculate, rather than only to remember what had worked, became central to the profession. The change made engineering faster, more economical and more capable of solving problems nobody had solved before. It did not make experience obsolete.

This article traces how engineering learned to use science, why formal engineering education developed, what each tradition does well, and what that history teaches technical businesses about design margins, models, judgement, capability building and regulation. It is general information for engineers, technical managers and business owners.

When practice came first

Almost every older engineering field developed a practice first and an explanation later. Masonry builders understood arches, buttresses and proportions from experience. Millwrights built water wheels, ironmasters ran furnaces and boilermakers made steam boilers using knowledge accumulated through generations. Theory, when it arrived, mostly explained and refined something that already worked.

Experience is a powerful teacher, but it has a built-in limitation. A design that has worked before shows that its margins were enough; it cannot show how much of each margin was doing useful work and how much was merely reassuring. Experienced designers therefore tend to be conservative, for good reason, and the cost of that conservatism is carried in extra material, weight and expense. Experience also struggles with problems that have no precedent, because there is nothing to imitate.

The first engineering schools

France created engineers deliberately earlier than most countries. The École des Ponts et Chaussées, the school of bridges and roads, opened in 1747 and is usually regarded as the first civilian engineering school. In practice it still relied heavily on apprenticeship, with theoretical lectures given only occasionally.

The more significant change came with the École Polytechnique, founded in 1794, which made mathematics, physics and chemistry the foundation of engineering education rather than optional extras. During the eighteenth century, French engineers and scientists had developed much of what is now called engineering science, the application of theories such as statics and dynamics, and of scientific method, to engineering problems. Germany and other European countries soon established technical schools on similar lines.

The argument that carried engineering science was not intellectual elegance but economy. By the early nineteenth century, it was becoming clear that a structure or machine designed by calculation to carry its expected load with a known margin could be cheaper than one designed by experience alone, because calculation could identify which margins were doing work.

Electrical engineering: built outward from science

Electrical engineering is the clearest example of an industry built from laboratory results. It had no craft tradition to refine. Its foundations were scientific discoveries:

From Volta’s battery to commercial electric power took roughly eighty years, a fraction of the time it took older fields to mature. The telegraph, generator, electric light and alternating current systems were each developed by people who had studied the science, and the field advanced at a pace that craft-based fields had never matched.

Even so, industry ran ahead of education. Formal teaching of electrical engineering in American universities became established only towards the end of the nineteenth century, when electric lighting systems were already operating commercially. That is a normal pattern: new industries usually develop before curricula catch up.

Building capacity quickly

The United States was slow to establish engineering schools. By one account, only two institutions offered engineering instruction there in 1840, the Military Academy at West Point and the Rensselaer school in Troy. The Morrill Land Grant Act of 1862 granted public land to fund colleges teaching agriculture and the mechanical arts, and within a decade the number of American engineering schools grew from a handful to about seventy.

That growth shows that technical capacity can be built deliberately and quickly when it is treated as infrastructure and funded. Building a research tradition took longer. Early American schools mostly adapted European methods, and their contribution to advancing engineering came later.

Fields that kept learning by experiment

Not every field followed electrical engineering’s path. Steelmaking, structures and water treatment continued to advance substantially through experiment and, at times, through failure.

• Steelmaking. Henry Bessemer’s converter of 1856 produced steel quickly by blowing air through molten iron, but it could not use the phosphorus-rich ores common in Europe. In 1878, the cousins Sidney Gilchrist Thomas and Percy Gilchrist developed a lining for converters that removed phosphorus, opening vast ore deposits to steelmaking. The solution came from chemistry and experiment rather than from established theory.
• Bridges. In 1907, the Quebec Bridge in Canada collapsed during construction, killing about 75 workers. The inquiry found that the structure’s own weight was substantially greater than the designers had assumed, and that the calculations had not been revised after the span was lengthened. In 1940, the Tacoma Narrows Bridge in the United States tore itself apart in moderate wind because its slender deck was vulnerable to aerodynamic effects that designers of the time did not adequately account for. Both failures changed engineering practice.
• Water treatment. Sand filtration and later chlorination were adopted because they demonstrably reduced disease, before the mechanisms were fully understood.

These cases show the limits of calculation. A calculation is only as good as its model, its assumptions and its inputs. When a design moves beyond the range where its assumptions have been tested, by size, speed, material or environment, new failure modes can appear that the model does not include.

What each tradition does well

Formal education did not replace supervised experience. It was added to it, because each covers what the other cannot.

Modern professional frameworks reflect that combination. In Australia, Engineers Australia accredits engineering degree programs and administers Chartered status, which requires demonstrated competence developed through practice, and several states, including Queensland, Victoria and New South Wales, operate statutory registration schemes for professional engineers doing certain types of work. Australia was also a founding signatory to the Washington Accord in 1989, under which accredited engineering degrees are mutually recognised among member countries. Registration requirements differ between jurisdictions and change over time, so check current requirements before relying on any summary.

Patterns that repeat

Looking across the nineteenth century, several patterns recur whenever a field acquires a science:

• The system beats the device. Edison’s lamp succeeded as part of a designed system of generation, distribution and metering, and the same was true of arc lighting and alternating current.
• Priority is usually contested. Joseph Henry and Michael Faraday each discovered electromagnetic induction, and Bessemer’s process had a rival claimant in the American William Kelly. When enabling knowledge matures, several capable people often reach the same result.
• Removing a limit creates a market. The transformer made long-distance transmission possible, and the Gilchrist Thomas process made phosphoric ores usable. Demand often did not exist until the constraint was removed, so forecasts made under the constraint understated the outcome.
• Regulation can slow a technology. Britain’s Electric Lighting Act of 1882 allowed local authorities to buy private electricity undertakings after 21 years, which discouraged investment. It is commonly cited as one reason electric supply developed more slowly in Britain than elsewhere, until the law was amended in 1888.

Lessons for technical businesses

Analysis pays for itself by finding which margins work

The commercial case for engineering analysis is economy. Standard designs inherited from experience often carry margins nobody can explain. Analysis against current standards can show where material, weight or cost can be saved safely, and where a margin is thinner than everyone assumed.

Check models against reality

Calculation is only as good as its assumptions. The Quebec Bridge failed because assumed weights were not checked against the evolving design. Revisit assumptions when designs change, test prototypes and compare predictions with measurements. Make sure tests could actually reveal a problem; the tests that cannot fail article explains why some checks give false comfort.

Be cautious beyond tested ranges

When a product or structure becomes larger, faster, lighter or used in a new environment, look for failure modes that experience and existing models may not cover.

Combine knowledge and supervised experience

Formal training and on-the-job experience are complements. Graduates need supervised practice to build judgement, and experienced tradespeople benefit from understanding principles. The building workforce capability in manufacturing article covers practical methods for developing skills inside a business.

Capture what experience knows before it leaves

Experienced people hold knowledge that calculations miss, such as how a material behaves in a particular process or which assembly sequence avoids distortion. Pairing them with people trained in analysis lets each test the other’s knowledge.

Expect to train ahead of the curriculum

New technologies usually reach industry before formal courses cover them. Businesses adopting new methods should plan their own training rather than waiting for graduates who already know them.

Engage with regulation

Regulations can enable or hold back technologies. Keep track of the standards and rules that govern your products, including which edition applies; the which edition of a standard applies article explains why that question matters.

A worked example

This is an illustrative example. A fabricator makes steel stairs and platforms for industrial sites, about 150 stairs a year. Its standard designs were set decades ago by an experienced founder and have never been formally checked against current standards. A senior fabricator who knows the designs well is planning to retire within two years.

Analysis. The business engages a structural engineer to check its standard designs against the current Australian standards for fixed platforms, walkways, stairways and ladders, AS 1657, and for steel structures, AS 4100. The check finds that stair stringers are much heavier than needed, while one bolted connection used on longer platforms has less capacity than assumed for some load cases.

Changes. Stringers are resized, saving about 8 kilograms of steel per stair. At an assumed material and fabrication cost of $5 per kilogram, that is about $6,000 a year across 150 stairs, plus easier handling. The connection is redesigned and existing installations with long platforms are reviewed with their owners. A prototype stair is load-tested to confirm the revised design before it is adopted.

Knowledge capture. A graduate engineer works alongside the senior fabricator for a year, documenting the rules of thumb used in the workshop and checking each one by calculation. Most turn out to be sound, including a welding sequence that controls distortion on long stringers, which no calculation had captured and which becomes part of the written procedure.

Result. Calculation found both wasted margin and a hidden weakness; experience supplied knowledge the analysis lacked. As in the history, the business needed both.

Applying these lessons in an Australian business

• Review inherited standard designs against current standards with qualified engineers.
• Record design assumptions and revisit them when designs change.
• Test prototypes and compare predictions with measurements.
• Watch for new failure modes beyond tested ranges.
• Pair experienced people with analytically trained people to capture knowledge.
• Plan training for new technologies ahead of need.
• Check registration and standards requirements for engineering work in your jurisdiction.

Questions worth considering

• Which of our standard designs rely on rules of thumb nobody has checked?
• Where might our margins be larger than needed, and where might they be thinner than we think?
• Which products are being pushed beyond the range where our experience applies?
• What knowledge held by experienced staff is not written down anywhere?
• Which new technologies are we adopting faster than our people are being trained?

Bringing it together

Engineering learned to use science during the nineteenth century, most dramatically in electrical engineering, which grew from laboratory discoveries into an industry within decades. Engineering schools followed, built on mathematics and physics, and capacity grew quickly where it was deliberately funded. Yet fields such as steelmaking, structures and water treatment kept advancing through experiment, and failures such as the Quebec and Tacoma Narrows bridges showed the limits of calculation. For technical businesses, the lessons are to use analysis to find which margins work, test models against reality, respect the limits of tested ranges, combine formal knowledge with supervised experience and engage with the regulation that shapes their field.

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Source: KEVOS editorial notes, drawing on an earlier KEVOS engineering history series on applied science and engineering education, together with established histories of engineering. Professional registration and accreditation arrangements are summarised for orientation only and should be checked against current requirements. The worked example is illustrative. This article is general information.