Maurice Koechlin’s structures have become world-famous landmarks. Animation by Klaas Kaat.

The Swiss ‘magician of iron’

Engineer Maurice Koechlin created some of the icons of engineering prowess: the Statue of Liberty, the Eiffel Tower, and numerous bridges. Yet others reaped the glory.

Helmut Stalder

Helmut Stalder is a historian, publicist and book author specialising in economic, transport and technical history.

Maurice Koechlin is one of those people whose creations are much more famous than they are. Not many people know that this talented Franco-Swiss engineer played a key part in the construction of the Statue of Liberty, the Eiffel Tower and the Garabit Viaduct.

Karl Culmann’s star pupil in graphic statics

Maurice Koechlin was born into an industrial family in the Alsatian town of Buhl in 1856. The Koechlins were originally from Stein am Rhein, spreading out via Zurich and Basel to Alsace. When Alsace came under Prussian control during the Franco-Prussian War, Maurice’s father sent him to the ETH in Zurich (then still known as the Polytechnikum) in 1873 to study engineering. In 1876 Maurice Koechlin became a citizen of Zurich and therefore also acquired Swiss citizenship.

One of his most important professors and mentors was Karl Culmann, the inventor of graphic statics. This new, graphical method was used to analyse forces on beams and framework structures. The method experienced a boom, particularly in the construction of railway bridges. Koechlin was Culmann’s most gifted student and completed his studies in 1877, coming top of the class.

**Maurice Koechlin’s father ran a spinning mill and cloth factory, so Maurice learned about the requirements of the industrial age early on. Photo taken circa 1876.** e-pics

Talented engineer recruited by Gustave Eiffel

Armed with these skills, Koechlin moved to France and started working as an engineer for a railway company in the eastern part of the country. France was in the midst of an engineering heyday, driven by engineer Gustave Eiffel, whose company was big in the railway bridge business. The Maria Pia Bridge over the Douro in Portugal was built in 1877. It was designed by Eiffel’s leading engineer and associate, Théophile Seyrig. Eiffel was subsequently asked to build a similar bridge in the Auvergne region of France – the Garabit Viaduct over the River Truyère. However, Seyrig wanted a bigger financial stake and a share of the publicity, most of which Eiffel had deftly kept for himself. The pair fell out, and Eiffel showed Seyrig the door. He then started looking for a competent successor, reaching out to Karl Culmann, who recommended his star graduate, Maurice Koechlin.

In November 1879, Koechlin, then aged just 23, started working as chief engineer at Eiffel’s firm. Koechlin and his boss were very different in character, but they complemented one another. The ambitious and extroverted Eiffel was something of a social butterfly, had political ties, a keen business sense and managed to secure some spectacular projects. The reserved and publicity-shy Koechlin, on the other hand, worked away on the sidelines and solved tasks with innovative ideas and technical flair.

**Maurice Koechlin (first left) and Gustave Eiffel (second left) under the Garabit Viaduct.** Wikimedia

The Garabit Viaduct was Koechlin’s first major project. He worked with Emile Nouguier – an engineer specialising in construction organisation at Eiffel – to completely rework the specification, including the addition of a parabolic rather than a circular arch. The Garabit bridge was built in 1884.

**Assembly of the bridge arch at a dizzying height: at 122 metres high, the Garabit Viaduct was and remained the world’s highest railway bridge for 25 years. It is now a UNESCO world heritage site.** Wikimedia

In parallel, Koechlin designed another viaduct in the Nouvelle-Aquitaine region. For this beam bridge over the River Tardes, he developed a close-mesh lattice girder instead of the usual cross-braced truss, which spanned over 100 metres between two masoned columns. The bridge was completed in 1885 and now has protected monument status.

Inside the Statue of Liberty

There was another reason why Eiffel was dependent on a capable, hard-working chief engineer: the firm had been awarded the most exciting major project at the time – the Stature of Liberty. French sculptor Frédéric-Auguste Bartholdi was working on the colossal statue ‘La Liberté éclairant le monde’, which the French wanted to gift to the United States in honour of the alliance between the two countries during the American Revolutionary War. A number of parts had already been made before it had been decided how the 46-metre-high and 225-tonne figure made from hammered copper panels would be held up. The commissioned architect died unexpectedly, without leaving behind any instructions.

The contracting authority then contacted Eiffel, who in turn entrusted the task to Koechlin. In the same way as for a bridge, the engineer designed a structural framework consisting of four strutted columns and a double spiral staircase, as well as a projecting framework structure for the right arm. Instead of a rigid structural framework, Koechlin’s design featured a flexible lattice skeleton. This flexibility proved game-changing as the copper coating that was mounted on it allowed the statue to withstand temperature fluctuations and changing wind loads.

From 1881, ‘Lady Liberty’ was erected for testing purposes on the site of the foundry in Paris, and it towered over the surrounding buildings for more than two and a half years. At 93 metres high, it was the tallest statue in the world until 1959. Wikimedia / Wikimedia

Lady Liberty was officially inaugurated in 1886. But Maurice Koechlin didn’t get any of the limelight. It was only in 1936, on the occasion of the 50th anniversary, that the press praised the unassuming engineer for his crucial contribution to the masterpiece.

Early sketches produced on the living room table

But Maurice Koechlin’s greatest coup was the Eiffel Tower. In early 1884, the French government announced that it would be hosting a world fair to mark the centenary of the French Revolution. The then 28-year-old wanted to create something phenomenal. He and his colleague Émile Nouguier started thinking of their own accord about a project that would “make the upcoming fair more attractive”. On the evening of 6 June 1884, as Koechlin was sitting at the table in his apartment at 11 rue Le Chatelier, he produced a quick, manual sketch of the ‘300-metre-high pylon’. He then jotted down a calculation of the vertical load and the horizontal wind load on the sketch.

To illustrate the height, Koechlin added a number of famous monumental structures alongside the tower on a scale of 1:50: Notre-Dame, the Arc de Triomphe, the Statue of Liberty, the columns on Place Vendôme and Place de la Bastille, the Obelisk on Place de la Concorde and a luxury town house. e-pics

The austere technical sketch shows the parabolas, the iron framework, six floors, and the flat arches on the lowest level. Koechlin intended to construct the tower with a supporting framework similar to the Statue of Liberty’s, only visible. The framework offered little resistance to the wind and made it possible to build higher than ever before. His wrought iron tower was to be the tallest in the world – a symbol of the spirit of the industrial age, right in the heart of Paris.

Eiffel hesitant before jumping on board

The engineers presented the structural drawing to Gustave Eiffel, who explained that he “had no inclination to take an interest in it”, as Koechlin wrote in a summary of the tower’s origins. But he allowed them to continue working on it. They passed the sketch on to architect Stephen Sauvestre, asking him to make it more aesthetically pleasing. Sauvestre reduced the number of platforms, added the unnecessary yet elegant semicircular arches at the foot, the glass pavilion on the first floor, and the cupola at the top. The architectural drawing bears the words: “Drawn by Nouguier, Koechlin, Sauvestre”. This time Eiffel recognised the potential, adding his name under the other engineers’, alongside the words ‘Présenté par G. Eiffel’. A patent was hastily filed for the construction process “allowing the construction of metal supports and pylons capable of exceeding a height of 300 metres”. The patent was registered in the names of Eiffel, Nouguier and Koechlin.

**Patent document for Koechlin’s construction: Brevet no. 164364, 18 September 1884, signed by Koechlin, Nouguier and Eiffel.** Google Arts & Culture

Eiffel immediately bought the patent rights from them. Under the contract, he was then allowed to realise the project in his name, but had to credit the engineers as initiators. By way of a fee, he pledged them a percentage of the construction costs – 51,418 French francs each. According to Koechlin, Eiffel then did everything necessary, employing his usual tenacity, to ensure that the project would be accepted and go ahead.

“An eyesore”

Eiffel, who had not contributed anything to the design, then demonstrated all his tactical shrewdness in making sure that the tower was a success. While Koechlin carried out detailed calculations on the construction, Eiffel railed against his rivals, hoping it would help him win the competition and secure the contract. The specifications set out the rules for an open competition to "include a study of the possibility of raising an iron tower with a square base of 125 meters per side and a height of 300 meters.” Eiffel’s firm immediately won the contract.

But there was some resistance to the construction of the “useless and monstrous Eiffel Tower in the heart of the French capital”. People dubbed it “an odious column of bolted metal” that would rise above Paris like a gigantic, black smokestack, crushing all the city’s monuments under its barbaric bulk.

Eiffel went ahead with the project – and Koechlin worked with around two dozen technicians to produce over 700 overall plans and 4,000 detailed sketches. By the time it opened in May 1889, public enthusiasm was high. The Eiffel Tower by then represented a terrific achievement by Gustave Eiffel.

The building of the Eiffel Tower depicted in a graphic model. Youtube

“The idea and the calculations were mine”

Eiffel reaped the glory for the tower, and it made him world famous. Koechlin never expressed any regret about it, however, and continued to work faithfully with Eiffel. When the latter was convicted following his involvement in the Panama Scandal, Koechlin took over the management of Eiffel & Cie, later becoming the Chair of the Eiffel Tower Company. In 1890 he was made an officer of the French Legion of Honour, in 1903 he was awarded the gold medal by the French Engineering Association, and in 1929 he became an honorary member of the society of former polytechnicians at ETH Zurich. But recognition was limited to specialist circles, as Koechlin was overshadowed by the name Gustave Eiffel. Only in 1939, on the 50th anniversary of the tower, did Koechlin call to mind his role as its creator, saying to a journalist: “The father of the tower is Eiffel. But the idea and the calculations were mine.”

**Postcard from 1939: to mark the 50th anniversary of the Eiffel Tower, Koechlin’s design sketches were published.** 1900lartnouveau.com

Koechlin knew that without Eiffel’s tireless efforts and dedication, the tower would never have been built. But he also knew that Eiffel could not have built the modern wonder of the world without him. Koechlin spent his twilight years with his Vevey-born wife Emma Rossier in Veytaux on Lake Geneva, where he built a house in 1900. He died in 1946 at the age of 90 and was buried in Vevey.

Thanks to the Eiffel Tower, Gustave Eiffel became world renowned as the ‘magician of iron’. Maurice Koechlin is commemorated by a waxwork in the Eiffel Tower, a small monument and a primary school in Buhl, and three streets named after him in French villages. Meanwhile, in Switzerland, there is no monument to the Swiss ‘magician of iron’, the genius in Eiffel’s shadow.

More of: 20th / 21st century Technology Architecture

Further posts

Powered by water, driven by ambition

Caroline Calame 27.02.2025 Jonas Sandoz acquired the concession to operate mills in the caves of Col-des-Roches thanks to his political acumen. It was a successful venture – until he ran into financial difficulties.

Maps and Switzerland’s linguistic destiny

Felix Frey 09.01.2025 Poncello or Puntcell? Illarsaz or Illarse? Kalbermatt or Chalbermatt? The spelling of place names has frequently been a contentious issue in all parts of Switzerland, particularly when it comes to striking the right balance between standard language and dialect.

Dialect or standard language? This question occupied the topographers. Illustration by Marco Heer.

A moving mountain: the enigma of the Rosablanche

Felix Frey 29.08.2023 In 1915, land surveyors realised that the summit of the Rosablanche mountain in the canton of Valais had moved several metres in the space of just a few years. Today, the cause of the movement is more relevant than ever.