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IWC Mk 11 RAF Radium Dial, 1951 — view 1 of 6
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Instruments · Deck watch

IWC Mk 11 RAF Radium Dial, 1951

DocumentedDocumented from a dealer's listing; attribution and date as stated by the dealer.
Maker / attribution
IWC (maker)
Date
1951
Country of origin
Switzerland
Object type
Deck watch
Stock no.
Product 1603784310871
Credit line
Dealer listing, S.Song Watches (product 1603784310871)
Catalogue title (original)
IWC Mk 11 RAF Radium Dial (English)

View the source record (dealer listing) ↗ (opens another website in a new tab)Suggest a correction

Record summary

Catalogued by S.Song Watches (dealer), Seattle (stock number Product 1603784310871), this is a deck watch by IWC, made in Switzerland, dated 1951. The Atlas places it in the Modern Mechanical Horology period (1945 – 1969) of its Instruments collection. The record is illustrated with 6 photographs.

Assembled from the source record's structured fields. Dates and attributions are given as the source states them; where a field is missing the Atlas leaves it blank rather than estimating.

Catalogue description

Dealer description — S.Song Watches

The Mk 11 wristwatch issued to the British Royal Air Force (RAF) was aviation’s equivalent to the marine chronometer- aptly nicknamed the air chronometer. Considered by many to be the original Pilot’s watch, it was made to the incredibly strict 6B/346 specifications and was one of the costliest commissions for a wristwatch by a military. Some of the 6B/346 specs included the need to be regulated or adjusted to a chronometer level, the need for a hacking function, for it to be waterproof and to be anti-magnetic. These all stemmed from real needs from pilot’s in the RAF who relied on these watches both for navigation and timing purposes. The Mk 11 watches can lay claim to be the first watch that was built from the ground up to be antimagnetic. With a thick iron dial and a soft iron dust cap, this created a Faraday cage, protecting the movement from any interference from the other equipment on the plane. It was, without doubt the most advanced watch issued to the military at the time. This example is perhaps one of the rarest iterations of the Mk 11. Nearly all of the Mk 11s either have service dials from IWC, or had their luminous material replaced with tritium by the Ministry of Defence. This IWC Mk 11 somehow managed to escape the change and retains its original radium dial as denoted by the lack of the ’T’ marking on the dial most would be used to seeing. Something like this really does not come up very often and to find one in this condition is unbelievable. Often misnamed as a Mark 11 or Mark XI, the correct spelling according to the MoD is actually Mk 11. A perennial favourite amongst collectors partly due to its utilitarian no-nonsense layout and incredible quality, the Mk 11 is a great casual watch to wear as a daily beater. With only roughly 8000 pieces produced, and this one made even rarer by the radium dial, it is a real collector piece for hardcore military collectors.

Historical context

Modern Mechanical Horology (1945 – 1969)

Tool watches for divers, pilots and astronauts; electric watches anticipate the electronic age.

Electronic instruments, quartz frequency standards and the first atomic clocks transformed precision timing in laboratories and broadcasting.

Read the period in the timelineMore instruments from this periodEarlier: Golden Age of Mechanical Watchmaking

Atlas type guide

Marine chronometers

A marine chronometer is a precision timekeeper carried at sea to find longitude: the navigator compares local noon, observed with a sextant, with the time at a reference meridian kept by the chronometer. Each hour of difference corresponds to fifteen degrees of longitude. John Harrison proved the method in the 1760s; Pierre Le Roy, Ferdinand Berthoud, John Arnold and Thomas Earnshaw then developed the detent escapement and the compensation balance that made chronometers practical to manufacture.

By the nineteenth century London, Liverpool, Le Locle and Glashütte supplied navies and merchant fleets. A typical box chronometer has a spring-detent escapement, a fusee to equalise mainspring torque, a bimetallic compensation balance with a helical balance spring, and is mounted in gimbals inside a wooden box so that it stays level.

What to look for

  • Gimbals and a three-tier wooden box with a glazed inner lid.
  • A power-reserve ('up and down') indicator on the dial, usually showing 56 hours on two-day instruments.
  • Spring-detent escapement and a cylindrical (helical) balance spring visible through the movement.
  • Admiralty or navy marks (broad arrow), and rating certificates from observatories.
  • The maker's number on the dial and movement; many makers' registers survive, allowing dating.

Dating clues

  • Earnshaw-type spring-detent chronometers became standard after about 1800.
  • Auxiliary compensation devices on the balance appear from the mid-nineteenth century.
  • Quartz and radio time signals ended routine use of mechanical chronometers in the 1970s and 1980s.

General guidance written by the Atlas editors about this kind of object. It is not a statement about this particular piece; for that, rely on the source record above and on physical examination.

Read next:Spring detent (chronometer) escapementFuseeBalance spring (hairspring)Detent escapement

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