A. Lange & Söhne Scales Down the 1815 AUF/AB: two Gold Versions Measuring 37.5 Millimetres

A. Lange & Söhne is introducing a smaller version of the 1815 AUF/AB in 2026. The two new models combine a 37.5-millimetre case in red or white gold with a blue dial and silver-coloured sub-dials. Each variant is limited to 300 pieces. Like the 39-millimetre versions, both models continue to be powered by the hand-wound calibre L051.2.

The generation launched in 2013 measured 39 millimetres in diameter; the new editions now measure 37.5. What sounds like a very small difference significantly alters the relationship between the case, the dials and the open space on the 1815 AUF/AB, with its large dial opening. Together with the new colour scheme, this creates a noticeably more compact and modern interpretation of the 1815 AUF/AB.

A familiar model on a more classic scale

The dial of the 1815 AUF/AB is characterised by two subsidiary dials: the power reserve indicator on the left and the small seconds dial on the right. It is precisely for this reason that the change in size has a greater impact than the sheer difference might initially suggest. In a round watch with a narrow bezel, where the dial occupies a large part of the case front, every millimetre affects the proportions between the dial surface, the lugs and the case edge. With a diameter of 37.5 millimetres and a height of 8.7 millimetres, this reinterpretation is likely to appear more compact and formal than the 39-millimetre version, without the displays being pushed closer together.

This is an editorial assessment, not a statement regarding the replacement of existing models within the collection. One thing is certain: A. Lange & Söhne utilises the familiar design architecture whilst altering its emphasis. The smaller case makes the historic design motifs appear less expansive, but more concentrated. For a watch whose design heritage harks back to pocket watches, this is a remarkable step. It thus moves closer to the understated dimensions and proportions that were once standard and commonplace for elegant hand-wound watches.

Blue, argenté and two different shades of gold

The dial is made of 925 sterling silver. Two argenté-coloured sub-dials stand out clearly against the blue background and divide the lower half of the dial. Arabic numerals, a railway-style minute track and the recessed centre echo the design language of historic pocket watches. However, the colour scheme frees these elements from a purely archival context: the dark blue and the light-coloured subsidiary dials give the 1815 AUF/AB a very attractive and contemporary appearance.

However, it is not just the colour scheme of the dial that is key to the 1815 AUF/AB’s classic yet modern appearance. White gold keeps the colour scheme cool and emphasises the graphic contrast between blue and argenté. Rose gold provides a warmer contrast to the blue dial and integrates the case more closely into the colour scheme. The hands, crafted from 750 gold and blued steel, further distinguish the displays. Both the front and the display caseback are made of sapphire crystal.

The smaller case size does not alter the familiar layout of the dials. At 8 o’clock, a sub-dial indicates the remaining power reserve, whilst the small seconds dial at 4 o’clock provides a visual counterbalance. The two dials are deliberately positioned side by side to stabilise the dial below the central axis. In the smaller case, it is precisely this balance that helps ensure that, whilst the A. Lange & Söhne 1815 AUF/AB appears more compact, the two subsidiary dials are not visually crammed together.

The fact that the downscaled 1815 AUF/AB fits perfectly into the manufacturer’s current range is also demonstrated by the recently downscaled Saxonia Annual Calendar in 36 millimetres – read more about this in our article.

What ‘AUF’ and ‘AB’ mean in technical terms

The term dates back to a power reserve indicator patented for A. Lange & Söhne in 1879. ‘AUF’ indicates that the movement is fully wound, whilst ‘AB’ marks the end of the stored power reserve. In between, you can see how much of the total 72-hour power reserve is still available. In a hand-wound watch, this is not some contrived gimmick, but a piece of immediately useful information: when the movement needs to be wound again.

Equally remarkable is the planetary gear train of the power reserve indicator. It is integrated directly into the in-house calibre, rather than being fitted as a separate module onto an existing calibre. Put simply, such a gear train distributes movements within a compact gear arrangement and thus transmits the tension in the mainspring to the hand. A superimposed assembly would introduce additional layers and thus potentially increase the movement’s height. This integration is therefore particularly appropriate for the 1815 AUF/AB, which, despite its power reserve indicator, measures just 8.7 millimetres in height.

The L051.2 calibre remains the technical foundation

Behind the sapphire crystal caseback of the A. Lange & Söhne 1815 AUF/AB lies the familiar Lange in-house calibre L051.2. Its dimensions are particularly relevant to the new format: With a movement diameter of 30.6 millimetres, only a comparatively narrow bezel remains within the 37.5-millimetre case. The movement’s height of 4.6 millimetres also contributes to the slim overall height of 8.7 millimetres.

The calibre comprises 245 components and operates at 21,600 vibrations per hour, or 3 hertz. The calibre has 29 jewels, seven of which are set in screw-mounted gold chatons. The classic screw-mounted balance operates in a non-escapement oscillation system with an in-house-developed balance spring. It is regulated in five positions to ensure it runs as evenly as possible in different positions.

Visually, the three-quarter plate, crafted from natural nickel silver, defines the visible rear of the movement. The winding wheels mounted on it are also sun-brushed, and the decoration on the balance cock is hand-engraved. They lend the technically unaltered foundation a clearly recognisable artisanal signature, whilst the actual redesign of the 1815 AUF/AB focuses on the case and dial.

Two references, 300 pieces each

The rose gold version bears the reference number 244.037 and is presented on a hand-stitched reddish-brown alligator leather strap with a rose gold pin buckle. Reference 244.028 combines white gold with a blue, hand-stitched alligator leather strap and a white gold pin buckle. Both versions feature a numbered limited-edition engraving and are limited to 300 pieces each.

The watches will be unveiled at the Concours of Elegance at Hampton Court Palace. This gathering of historic cars in a courtly setting provides a fitting backdrop for the presentation of mechanical timepieces. The significance of these editions ultimately lies less in a new complication than in the focused reworking of the design and appearance of the A. Lange & Söhne 1815 AUF/AB.

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