Finally! Sinn Revives an Iconic Military Chronograph

Sinn fans rejoice; the Frankfurt favorite has finally released a watch we’ve all been waiting for. 156 is a number that most Sinn fans have memorized as it refers to one of the most excellent watches in the Sinn archives, not just because of its looks but also because of its lineage and movement(s). You see, the story of the 156 begins with a watch by a different brand altogether, the Heuer-Leonidas Bundeswehr 1550 SG, commonly called the “Heuer Bund.”

A pilot’s chronograph used in the 60s and 70s mainly by the German airforce, though others as well, the Bund was a remarkable tool watch of its day. Powered by the manual wound Valjoux 22 and Valjoux 230 calibers, they featured flyback mechanisms and a clean, bold design with large lumed numerals and a particularly appealing bezel layout. Measuring 43mm in diameter and 13mm thick, they were huge for the era, though in keeping with pilot watch tradition.

Helmut Sinn, the founder of Sinn, purchased old inventory of these watches in the 1980s, reconditioned them, added Sinn branding, and rebadged them as the Sinn 155 Bw. In the late 1980s, Helmut set out to create a new generation of military-issued pilot’s chronographs with the 156 by combining the case and general dial design of the 155/Bund with relatively new-to-the-market automatic chronograph movements by Lemania. Thus, the 156 is the direct successor to the Bund via the 155.

The 156s most commonly featured the “legendary” Lemania 5100 caliber. A notoriously rugged and shock-proof movement that went on to be used in watches issued to NATO jet pilots, the 5100 was created for tool watches. It’s not pretty or thin, but it is highly functional. A three-register design, it features a central minute counter for the chronograph function, along with central seconds. The best (I’ll stand by that) arrangement for a chronograph, the center minute hand is more legible and counts a full 60 minutes. Elapsed hours are at six, active seconds at nine, and a 24-hour dial (not independent) is at twelve. Accompanied by day and date windows at three, it’s about as practical as a chronograph can be. There were also versions of the 156 with the Lemania 5012, which lacked the 24-hour sub-dial, and appear to have been far less common.

Available in two versions, ones with and without the word “military” above the date window, the 156s were uniquely cool and attractive watches given their Bund-lineage, though they were never actually military-issued. Made for approximately 20 years, they are a slightly under-the-radar gem in the “neo” vintage world. I’ve personally owned one, as I like anything with a Lemania 5100 in it, but for the 43mm diameter and 15mm thickness, I adored it. I’ve since acquired a Sinn 256 (an article for another day), which has a similar aesthetic but a 38.5mm diameter and is powered by the Valjoux 7750.

But, I digress, as Sinn has finally launched a true continuation of the 156 line, some 20 years after they went out of production, with the 156.1 and 156.1 E models, which are production and limited, respectively. The 156.1 is the spiritual follow-up of the 156, combining the vintage DNA of the originals, specifically the 5012 models, with specs befitting a modern Sinn. Sinn maintained the overall look, harkening back to the Bund, with large Arabic hour numerals, sub-dials at six and nine, a bead-blasted case with drilled lugs, and a bowl-shaped case-back.

The edge-to-edge black friction bezel thankfully keeps the original layout but features two modern updates: Black Hard Coating over TEGIMENTED steel and a lume pip. The domed crystal appears to have a similar shape to the original acrylic, but it is now sapphire. The hands are very similar, but are slightly altered. The 12-hour sub-dial features a wedge shape, which on the 156 was used on the 24-hour dial. The hour and minute hands appear the same shape as the central minute and second counters; however, the highlight paint on the minute counter covers more of the hand. Notably, what was orange is now red.

The biggest change is within, as Lemania 5100s are long out of production. Powering the 156.1 is the SINN SZ01 movement. Based on the Valjoux 7750, Sinn developed the SZ01 as a Lemania 5100 stand-in. Like the 5100, it features a central minute hand, and, in its “full” form, a 24-hour dial at three, 12-hour counter at six, and active seconds at nine. Dropping the 24-hour hand for the 156.1 makes sense, given the 5012 models and the SZ01’s layout, allowing for the date at three, though it would have been fantastic to bring back the day as well.

The 156.1 measures 43mm in diameter and 15.45mm tall with a 22mm lug width. It’s a large watch, but in this instance, that’s accurate to the original. However, the lug width increased from 20mm, which might make the 156.1s wear even larger. The 156.1 is available on a leather strap for $4,540, and on a bracelet for $4,780.

The 156.1 E is a limited edition of 300, bringing some curious elements to the model. Some were vintage-inspired, and others were, well, out of nowhere. The most obvious change is to the lume and hand color. The lume on the numerals and hands has been switched from white to a warm ivory color, giving it a tinge of fauxtina. The active seconds hand has also been painted ivory, which doesn’t really make sense as it wouldn’t have been lumed.

The red has been removed entirely, replaced by white. As the 156s always featured bright orange, to my knowledge, I believe this is meant as a throwback to the 155. Furthering the aged look, the bezel is anthracite gray instead of black. It undoubtedly looks good if you don’t mind fauxtina, but I think it’s an odd design choice.

Odder still, the date window at three has been changed to a “Kollsman” altimeter design, partially showing the date before and after the current. This has no relation to anything and feels abruptly modern against the ivory accents. Though I’m not necessarily a fan of this window type, I don’t think it looks bad here as it balances out the logo. I’m just a bit baffled by the decision to include it. At least it’s on the limited edition and not the production version. The 156.1 E is priced at $4,970, including a bracelet and a strap.

In case you can’t tell, I’m genuinely excited about the 156.1. It’s been a long time coming. Sinn has revived the 155 several times over the last few decades, so it was time to give the 156 the spotlight. With that said, this is a situation where the modern watch costs more than the vintage, as 156 hover around $3k. But given the contemporary build and specs, as well as service costs of 5100s, there’s a logic to getting it over the vintage. Or getting both, which is very tempting. Sinn