Review – Urban Jürgensen 1140C, and the Detent Escapement Explained

Three times a seconds… At first glance the Urban Jürgensen & Sonner (UJ&S) 1140C is an alluring dress watch with the traditional attention to detail and lavish craftsmanship that goes into all the brand’s timepieces. Take a closer look though and you will notice the unusual, almost jerking motion of its seconds hand, which actually moves three times a second. Not just a pretty face, the reference 1140C is powered by sophisticated mechanics regulated by a detent escapement, a grail of chronometry adapted to fit in a wristwatch.

Urban Jürgensen stands for understated elegance, sophistication, and hand-craftsmanship. Launched in 2015, their reference 1140C is the continuation of the brand’s 2014 GPHG (Grand Prix de l’Horlogerie de Genève, the Oscars of watchmaking) first prize Winner in the Men’s Category. Remaining true to the pure style of the brand, this elegant dress watch is a new take on that design, housing the patented UJ&S detent escapement (for more information about Urban Jürgensen and its history, read our previous article here).

The Urban Jürgensen reference 1140C is powered by the P8 calibre with pivoted detent escapement. This twin barrel has a pleasing autonomy of 60 hours and features a stop-seconds for precise adjustment. With a diameter of 32mm and a thickness of 5.20mm, it runs at 21’600 vibrations per hour. As always with Urban Jürgensen, the finishing is top-notch with Geneva stripes radiating from the large balance wheel. The bridges, screw and jewel sinks are beautifully chamfered and the full balance bridge is open worked.

A grail of chronometry, the detent (or chronometer) escapement is one of the most accurate type of escapements. Created some 250 years ago, it was mostly used in marine chronometers and a few pocket watches. The balance wheel swings undisturbed during most of its cycle, except the brief impulse period, which is only given once per cycle (which explains why the seconds hand is only moving 3 times per second for a frequency of 21’600 vibrations per hour). It runs virtually without friction and the escape wheel teeth do not require oiling.

There are some disadvantages though. For example, it is rather sensitive to shocks, which is the reason why it was not used in wristwatches until very recently. Developed with Chronode, the UJ&S patented detent escapement features several enhancements compared to the traditional ‘chronometer’ escapement and was tested with Chronofiable. It features 3 stones for 3 individual functions: the center stone on the balance roller lifts the detent aside to release a tooth of the escape wheel from the locking stone while almost simultaneously the impulse pallet powers the balance wheel.

The superb dial features transferred Roman numerals. This real work of art requires painstaking hand work using a guilloche lathe to create its exquisite “grains d’orge” pattern enhanced by a fine layer of silver on its surface. The blued steel hands are diamond finished and designed in the characteristic Urban Jürgensen style, including a click-mounted diamond polished eye in rose gold. At 12 o’clock, the power reserve indication runs over 60 hours.

At 40mm, the UJ&S reference 1140 wears perfectly well with its distinctive stepped bezel and tear-drop lugs. The case is well proportioned and is a three-piece construction with a slightly domed sapphire crystal. It is worn on a black alligator strap with pin buckle, which as usual with UJ&S shows very pleasant quality and smoothness.

The Urban Jürgensen 1140C retails at 49,000 CHF. More information on www.urbanjurgensen.com.

Technical specifications – Urban Jürgensen 1140C

• Case: 40mm – pink gold case – sapphire crystals – 30m water resistant
• Movement: calibre P8 – manual winding – 60h power reserve – 21,600 vibrations/h – 28 jewels – hours, minutes, central seconds and power reserve indication – pivoted detent escapement.
• Strap: alligator leather with pink gold pin-buckle