JLC Mark XI
Why We Love it
Why We Love it–
Through much of World War II, allied aviators were donning the American-made A-11 service watch. While this tough-as-nails timekeeper performed meritoriously for soldiers and airmen alike, Britain's Ministry of Defense found that the production specifications of the A-11 were too broad and resulted in timepieces too imprecise for effective navigation.
As an answer to the A-11, the MoD issued new standards for the watches going to its RAF pilots. The new standard, coded 6B/346, required chronometer-grade performance and anti-magnetic properties. As the MoD did for all watch procurements, they turned to Goldsmiths & Silversmiths Co., Ltd., a High Street jeweler with Royal Appointments who worked with the general public, as well as royalty and government ministries. Goldsmiths & Silversmiths likely approached all of the major European manufactures, eventually giving contracts to two: Jaeger-LeCoultre and International Watch Company.
The resulting timepiece was the Mark XI Pilot's watch.
In addition to the relatively standard features present on the A-11 (center seconds, hacking and a stainless steel case) the Mark XI featured a soft iron dial and dust cover, surrounding the movement with iron on all sides (known as a Faraday cage) and shielding it from magnetic fields that can throw off timekeeping accuracy. It’s worth noting that the Mark XI was likely the first watch designed from the start to be anti-magnetic, a feature that would later become prevalent in military and professional timepieces.
As cool as the engraved case back and Faraday cage are, it’s a shame that the JLC Caliber 488 can’t be seen, since it’s one of the most beautiful movement of the era, not to mention built to an extremely high standard. The Cal. 488 is one of only a handful of chronometer grade movements from the 40’s and 50’s, designed to be accurate within just 4 seconds per day. While many assume that a military watch such as this would be the epitome of function over form, the gorgeous hand-finished Geneva stripes on the movement are squarely in the realm of haute horology. Putting the military heritage aside, the JLC Mark XI is simply one of the finest watches of its day.
This particular example is one of the cleanest and most lovely examples we've ever come across. With a crisp dial free of blemishes, sharp printing, and even its original "Cathedral" style hands (commonly replaced during contract servicing), this is a Mark XI you won't want to miss!
Analog:Shift stands behind the authenticity of our products in perpetuity.
Since our pieces are vintage or pre-owned, please expect wear & patina from usage and age. Please read each item description and examine all product images.
We back each Analog:Shift vintage timepiece with a one-year mechanical warranty from the date of purchase.
Please contact us prior to purchase for additional details on shipping and payment options.
Shipping & Returns
Shipping & Returns+
All of our watches include complementary insured shipping within the 50 states.
Most of our products are on hand and will ship directly from our headquarters in New York City. In some cases, watches will be shipped directly from one of our authorized partners.
We generally ship our products via FedEx, fully insured, within 5 business days of purchase. An adult signature is required for receipt of all packages for insurance purposes. Expedited shipping is available at an additional cost. We are also happy to hand deliver your purchase in Manhattan or you may pick it up at our showroom.
Returns must be sent overnight or by priority international delivery, fully insured and paid for by the customer. A restocking fee may apply. Watches must be returned in the same condition as initially shipped.
We welcome international buyers, please contact us prior to purchase for additional details on shipping and payment options.
JLC Mark XI