Derek Pratt

Derek Francis Pratt (9 May 1938 – 16 September 2009) was an English horologist and watchmaker. Regarded by many within the field as a highly accomplished 20th-century watchmaker, The three-year training was intended to include the finishing and assembly of a pocket watch, but due to a slump in the British watch industry, the syllabus was abruptly changed, and the class was denied that experience. This change led to Pratt's early departure from the program.

Career

After his work at Andrew Fells's companies, A. & M. Fell Ltd. and Felmada, ended in the early 1960s, Pratt took jobs at small companies specializing in microelectronics. One of them was with Kulicke & Soffa, a semiconductor manufacturer. In 1972, Pratt established his own business, specializing in watch and clock restoration and development. His horological interests included Gothic iron clocks such as those by Erhard Liechti (de); he also repaired household clocks, and worked on intricate and singular pocket watches. Amidst the Quartz crisis in the Swiss watchmaking industry, Pratt saw an opportunity and pursued a different approach: he acquired those seemingly obsolete tools of the trade, expanding his workshop with lathes, milling and guilloché machines. His focus was on hand making watches from the smallest screw to the case, and continuing restoration work on antique pieces. These machines were crucial for the work Pratt was to do under the historic brand Urban Jürgensen, which had been purchased and revived by Peter Baumberger in the late 1970s. Pratt also did a lot of work by hand, with a piercing saw or turns. and focused on the refinement of horological escapements. He developed noteworthy but little known solutions.

He started crafting entirely handmade remontoir tourbillon pocket watches using hand tools and hand-operated machine tools. The remontoir, producing a constant force, was an equally constant theme in Pratt's work: he encountered it both in the aircraft clocks as well as John Harrison's famous H4 marine chronometer. Pratt achieved a configuration where the remontoir directly drove the escapement, even within a tourbillon.

Consulting and collaborations

The Urban Jürgensen years In 1979, Peter Baumberger bought the 18th century Danish brand Urban Jürgensen und Sønner (now known as Urban Jürgensen or UJS) and in 1982, he brought Pratt on board as a consultant and technical director. Pratt would remain in that role until 2005. The vintage watch collector and expert Helmut Crott (and subsequent owner of the brand), noted in 2011 that perhaps "only his association with Derek gave Peter the confidence to finalize the deal. Derek was almost certainly the key factor in the acquisition of UJS; his extraordinary skills were needed for the 90 historic movements to be finished, cased and sold." Pratt's involvement with Urban Jürgensen was pivotal to the brand's revival and success with collectors in the 1980s and 1990s.

These decades were Pratt's most productive period: he made a series of pocket watches, mostly under the Urban Jürgensen name. He called these watches 'remontoir-tourbillons'. They are described in an article titled "A Tourbillon indicating full seconds with carriage-mounted remontoire [sic], twin barrels and up & down indicator" from July 1991. These watches marked the introduction of the Wankel-inspired Reuleaux triangle to operate the remontoir. The three watches also feature Pratt's engine-turning (guilloché) skills. Guilloché dials often have different patterns in different regions with the hard-to-execute change hidden by a chapter ring. Pratt's precise execution enabled variations in the guilloché pattern without the need to hide the junction. In the nineteen nineties, Pratt made a further series of three watches, known as the "second series".

The co-axial escapement was attributed solely to Daniels for many years. In the horological world, however, it is well known that Pratt played an important role in bringing this revolutionary invention to life. Not only did Pratt advise and discuss the mechanism for regulating the speed of clocks, he made the dual-purpose escape pinion for Daniels' escapement, using a spark erosion machine he had retained from his micro-engineering work. Daniels and Pratt spoke on the phone every Sunday morning for years, discussing what they were working on in great detail, with sketches exchanged by fax.

According to David Newman, former Chairman of the George Daniels Educational Trust, Pratt was Daniels' greatest horological friend, and a brilliant horologist. Daniels was among the contributors to "Remembering Derek", the Horological Journal's December 2009 issue containing Pratt's obituary. He wrote: "Derek's understanding of escapements was of great assistance to me. He immediately saw the benefit of the coaxial escapement and enthusiastically accompanied me in visiting factories to discuss its worth. He could speak French and Swiss German fluently, which was essential to our needs."

In a Horological Journal article from July 1991, Today, the co-axial escapement is central to the mechanical identity of any Omega watch, used in most of the mechanical watch models currently produced by Omega SA.

Daniels' tribute to Pratt ended with this note: "With Derek's passing we have all lost an important mechanical horologist of great experience and great knowledge, who was above all generous and congenial in his dealings with others. I have simply lost a brilliant horological friend and companion."

Wristwatch collaborations

Pratt loved solitude in the workshop, but cultivating friendships with fellow watch- and clockmakers was very important to him, too. In addition to the weekly calls with George Daniels, he had lively exchanges with peers in Switzerland, the UK and the US. He opened the doors to his workshop to countless students of horology and was interested in the next generation of watchmakers. and received its rarely awarded Tompion Gold Medal in 2006.

In 2014, DeCorte brought in Tom Bales, an American entrepreneur and watch collector. Bales invested into the completion of the watch, which Soprana took on. Since then, a handful of Derek Pratt Remontoir d'Égalité watches have been produced under the Derek Pratt trademark. With these watches, Derek Pratt's legacy is carried forth by Luca Soprana.

Independent watchmaking

The Oval

In 1982, as the Quartz crisis hit the Swiss industry, Pratt focused on his true passion – mechanical watchmaking – and embarked on a new project, a pocket watch known as The Oval. Officially named the Detent Escapement Tourbillon with Remontoir in an oval case, it has been described as Pratt's magnum opus. detent escapement, a central minute-wheel bridge, "flying" mainspring barrel, moon phase, power reserve and thermometer. The movement, visible through a hinged case back,

The shape also presented challenges. Pratt wrote in the same article "The problem uppermost in my mind was how to make an oval case complete with domed glass." He expressed hope that an engine-turning machine with an oval chuck he had in his arsenal would allow him to create the shape. He referenced the 1894 book "The Principles & Practice of Ornamental or Complex Turning" by John Jacob Holtzapffel and noted intending to use "an oval turning head made to fit on a Schaublin 102 lathe which was driven by the lathe headstock."

The Derek Pratt Double-wheel Remontoir Tourbillon

In 1997, Pratt created a pocket watch known as the Derek Pratt Double-wheel Remontoir Tourbillon. It was his submission for the Prix Abraham-Louis Breguet, a tourbillon contest held by the Breguet foundation to commemorate the 250th anniversary of Abraham-Louis Breguet's birth. The competition was to celebrate innovative mechanical ideas in horology. Pratt chose to make a Double-wheel Remontoire Tourbillon pocket watch, knowing that this produced far better timekeeping. It also perfected and enhanced two of Breguet's inventions. Pratt's realization that a fixed wheel with both inward and outward facing teeth would drive the twin escape wheels in opposite directions provided the only tenable solution for an échappement naturel in a tourbillon watch. The original timekeeper was completed by Harrison in 1759, and won him the Longitude reward (colloquially known as the Longitude Prize). Unlike Harrison's H1, H2 and H3 timekeepers, which are quite large clocks, H4 could be described as an oversized pocket watch. It is equipped with tiny diamond pallets in the escapement measuring a mere 1mm x 2mm – a very challenging part of the watch, and how the original pallets were made is a mystery.

Pratt started work on "his H4" in 1997. He worked on it for the next 12 years, researching, planning and making the various parts. Harrison's masterpiece H4 is located at the National Maritime Museum in Greenwich, London, and was at the time under the auspices of the MoD (Ministry of Defence) Art Collection. (Ownership of the Ministry of Defence Art Collection was transferred to museums and public bodies in 2017. )

For some work, Pratt commissioned specialists. The case was made by the late Martin Matthews, a fourth generation watchcase maker. The dial was made by Jos Houbraken, an enameler in the Netherlands. Charles Scarr did the engraving.

By 2009, much of the work on the movement was done. But with Pratt's health in decline, he consulted very closely with expert watchmakers Roger Stevenson and Philip Whyte of Charles Frodsham & Co. He maintained a long-standing friendship with the Frodsham team, and frequently spent time in their workshop, discussing detent escapements for wristwatches They described Pratt's 'Work in Progress' and the many steps: the making of the silver pair cases, the enamel dial, the piercing and engraving of various parts of the movement, as well as all the research that went into it. Stevenson noted how Pratt's generous spirit paid off in that he could now lean on the generosity of others: his friend, the horologist Anthony Randall, freely shared information as well as special tools from Randall's own work on another Harrison piece.

Pratt's CARD model of a double wheel remontoir escapement, made of cardboard and rubber bands. For the completion of the project, the Frodsham team introduced SolidWorks CAD – a tool Pratt never worked with, but was still around to witness (he often joked about his system, CARD, derived from models built out of cardboard). Pratt had completed much of the work on the movement himself, but there was still work to be done.

The Pratt-Frodsham H4 replica was exhibited as a loan alongside John Harrison's original H4 in the exhibition Ships, Clocks & Stars: The Quest for Longitude, celebrating the 300th anniversary of the Longitude Act. It was first shown at the National Maritime Museum in Greenwich, England, in 2014, and subsequently, at the Folger Shakespeare Library in Washington, DC, The Museum of America and the Sea, in Mystic Seaport, CT, and The Australian National Maritime Museum, in Sydney, Australia. In 1995, upon seeing his childhood friend Derek Goldsmith's unfinished indoor swimming pool, he was inspired to propose a site-specific water clock. He subsequently created two more outdoor water clocks for Luterbach and Langendorf, villages near his workshop. The Luterbach clock celebrated the municipality's 950th anniversary. The Langendorf one was for the 700-year-anniversary. He detailed his process in articles in the Horological Journal. The first Pratt water clock, as a proof of concept piece, was made and installed in his workshops. It was subsequently removed and gifted by his wife to the British Horological Institute at Upton Hall, where it remains on public display.

Personal life Derek Pratt was married to the Swiss Franziska Hess whom he'd met in a pub in the UK a few months before work took him to Switzerland, from 1965 to 1985.

Personal interests

In addition to horological heroes, Pratt also admired outliers in mechanical inventions: Franz Reuleaux, the inventor after whom the curved triangle is named. He drove a first-generation Mazda RX-7, a sportscar with a Wankel engine based on the Reuleaux triangle. The Reuleaux triangle made appearances in his watches time and again. Musée international d'horlogerie: Prix Gaïa (1999), "for his specialization in the repair of iron clocks and complicated watches as well as in the design of complicated pieces." The Worshipful Company of Clockmakers: Tompion Medal (2006), for "outstanding contributions to horology; a top class watch and clock maker; his ingenuity, technical ability and curiosity have helped to solve a variety of prototype and production problems; a supreme artist-craftsman"

Exhibitions Pratt's replica of John Harrison’s H4 timepiece was shown alongside the original at the 2014 exhibition Ships, Clocks & Stars: The Quest for Longitude, at the National Maritime Museum in Greenwich, England, presenting an account of why longitude was so important some 300 years ago.

Pratt also translated several books on horology, along with his wife, Jenny Haller Pratt, for example the MIH: Catalogue d'œuvres choisies, by Catherine Cardinal and Jean-Michel Piguet.

The book Derek Pratt Watchmaker

Documentary film The two-part documentary A detailed study of H4, directed and produced by Barbara Darby, gives insight into Pratt’s journey in the reconstruction of John Harrison's Longitude timekeeper H4, including his collaboration and commissioning other craftsmen for parts such as the case (Martin Matthews) and the dial (Jos Houbraken), and subsequently, Charles Frodsham & Co.'s completion of the watch.

Legacy The Derek Pratt Prize, a £20,000 award established in 2014, recognizes individuals or organizations worldwide that demonstrate innovation, ingenuity, elegance, and the highest standards of workmanship and precision in the craft and science of timekeeping. It is intended to inspire future generations in this field and is awarded no more often than every three years. There have been three awards to date: the late Martin Burgess was the first recipient of the Derek Pratt Prize in 2014. In 2018, it went to Charles Frodsham & Co Ltd, and in 2024, to Eliott Colinge.