A handful of engineers, two booms, a bust, and one accident that everyone learned from.
The rack railway was not invented once. It was invented again and again, each time by someone who looked at the last design and saw what was wrong with it. Most of them knew each other. Abt worked for Riggenbach; Strub was Riggenbach's pupil; Locher studied under the same professor who chose Riggenbach's tooth shape. Drag along the timeline, or pick a rack system to follow its story.
The first rack locomotives ever built were not for hills. In 1812 nobody was sure that smooth iron wheels could grip iron rails, so the Middleton Railway's engines drove a cog along a toothed rail at the side of the track.
The side rack pulled the engine off-centre and ruled out simple points. When plain wheels proved to grip well enough, the idea was dropped.
Marsh proposed a railway up Mount Washington in New Hampshire in 1858 and patented his rack the same year. His line climbs at up to 37 %, and it is still running.
Mount Washington became the model for Europe: Riggenbach sent his engineer Otto Grüninger to study it.
The sources disagree on when it opened: 1866, 1868 and 1869 are all given.
Riggenbach patented his rack in 1862, meaning it for main lines. Nobody wanted it until the Rigi. On 21 May 1871 the Vitznau–Rigi opened, the first mountain railway in Europe, built with Colonels Naeff and Olivier Zschokke.
It paid dividends of 15 to 20 % in its first three years, and set off a rush. When the next lines failed, Switzerland built no rack railway for thirteen years, and Riggenbach built abroad instead: Vienna, Budapest, Brazil, the Drachenfels on the Rhine. He also built the first rack points, at Rorschach–Heiden in 1875.
His engine works at Aarau had a young head of drawing office called Roman Abt. A surviving drawing is signed "N. Riggenbach, Directeur" and "Abt R, Constructeur".
On 15 August 1882, visiting Hautmont near Maubeuge in France, Abt sketched a rack of several flat bars side by side, their teeth and joints staggered. He was living in Paris, and Switzerland had no patent law until 1888, so he patented it first in France and then in Germany.
His bars were cheap, true and easy to curve. On 15 May 1885, on the Harz railway in Germany, the first sprung entry was tried: the train ran onto the rack "so gently" that the crew did not notice. Abt's system went on to 73 railways and over 570 km of rack.
He also invented the passing loop with no moving parts that over 220 funiculars use, and was president of the locomotive works SLM from 1920 to 1932.
Pilatus was too steep for any rack yet built. A Riggenbach line would have been twice as long, and the federal authorities feared that a vertical pinion would be lifted out of the rack by Pilatus's high winds.
Locher's first design was a steam rack monorail on stilts. What he built was a double-sided rack at up to 48 %, based on an idea of G. Stehlin of Basel. He contracted to finish by a fixed date, at 1000 francs a day if late, and opened on 4 June 1889 without ceremony.
"Many people thought he was crazy." In 1890 he proposed a Jungfrau railway in two air tubes, with the cars blown up the mountain like pistons.
Strub developed his rack in 1896 for the Jungfraubahn, which used it first in 1898. It was cheaper to make and lay, had no cheeks to fill with snow, and the engine's safety jaws could clasp its head as a brake and stop it lifting.
Strub also wrote the best accounts of the early Swiss lines. His 1893 description of the Wengernalpbahn is one of the main sources for the models on these pages, and in it he argued against the line's own rack-gap points.
Peter saw that with vertical teeth the safety against climbing out falls as the line gets steeper. Horizontal teeth make it the same at any grade, as at Pilatus, but his bar was simpler and could be used on mixed lines.
His line to the Dreikreuzberg at Karlsbad, at 50 %, would have been steeper than Pilatus. It was being built when the First World War stopped it.
G. Stehlin of Basel proposed the double-sided horizontal rack in the 1860s. Carl Culmann and Otto Grüninger chose the tooth form. Cathcart and the Baldwin works ran rack engines on the Madison Hill in Indiana from 1848. Adolph Klose improved the ladder for the Württemberg railways. R. Zehnder-Spörry built trailable automatic rack points at Glion in 1912. Hans Tribolet and Josef Marfurt made rack entries fast in the 1990s, and Pfenniger and the Rigi railways built points that bend, in 1999.
Sources: H. H. Peter, "Fünfzig Jahre schweizerischer Bergbahnbau", SBZ (1921); H. G. Wägli, "Carl Roman Abt" and H. Wismann, "Eduard Locher", Schweizer Pioniere der Wirtschaft und Technik (2005); P. Berger, Ferrum 86 (2014); SBZ (1883, 1885, 1918); V. von Röll (1923); ASME landmark brochure, Pilatusbahn (2001); Engineering (1896).