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The Encyclopedia of Horology

Pocket watch · Observation watch

A. Lange & Söhne U-Boot Beobachtungsuhr Kaliber 48

Partially verified

This observation watch by A. Lange & Söhne features a 60mm metal case with a numbered case back (203780) and an engraved dust cover. It is identified by the source as a U-Boot special edition of the Kriegsmarine 'Auf/Ab' observation watch, characterized by a fluorescent dial. The watch is powered by an A. Lange & Söhne Caliber 48 movement, serial number 203780, which includes an anchor escapement and swan-neck fine adjustment. Features include a power reserve indicator and decentralized seconds display, with blued steel hands. The auction description reports the watch is functional, with the dial described as unrestored and the movement described as clean. It is presented in a wooden box with a plaque reading 'Lange u. Söhne Glashütte'. The auction house classifies it as a military artifact from the World War II era.

Luminous dial view of the A. Lange & Söhne observation watch in its wooden presentation box.
Luminous dial view of the A. Lange & Söhne observation watch in its wooden presentation box. — Sammler-Uhren. Rights pending — permission not yet requested. Original source

Catalogue identity

Source
sammler-uhren.com
Category
Pocket watch · Observation watch
Maker / attribution
A. Lange & Söhne
Reference
Not recorded
Catalogue / lot identifier
Source URL identifies the listing
Source-reported date
c. 1940-1945
Source-reported place
Germany
Source-reported serial
203780

Source-reported attribution and specifications are not independent authentication. A listing does not establish present ownership, current display, availability or permission to reproduce.

Object description

Case and Dial Construction

The watch is housed in a 60mm metal case. The reverse side features a case back numbered 203780, and an internal dust cover that bears engravings. The dial is specifically noted as a fluorescent version, intended for low-light conditions associated with submarine use.

The display includes a power reserve indicator located at the 10 o'clock position labeled 'Auf' and 'Ab', and a decentralized seconds sub-dial positioned at the 3 o'clock mark. The hour and minute hands are constructed from blued steel. The auction description identifies the watch as a specialized edition for the German Kriegsmarine, particularly for U-boat operations, and notes that the dial remains unrestored.

Evidence for this section
  • “Große U-Boot Beobachtungsuhr von A. Lange & Söhne mit Leuchtzifferblatt, No. 203780”
  • “Gehäusedurchmesser: 60mm, Metallgehäuse, Rückdeckel nummeriert 203780, Staubdeckel graviert (siehe Fotos)”
  • “U-Boot-Ausführung mit fluoreszierendem Zifferblatt, Gangreserve-Anzeige und dezentraler Sekunde”

Movement and Mechanism

The internal mechanism is an A. Lange & Söhne Caliber 48, serial number 203780. It is designed as an anchor-escapement movement equipped with a swan-neck fine adjustment mechanism. This movement configuration was utilized in the 'Auf/Ab' observation watch models supplied by the manufacturer.

According to the documentation provided, the movement is in clean condition, and the watch is reported to be functional, although its specific timekeeping accuracy has not been verified or tested by the vendor.

Evidence for this section
  • “Werk: A.Lange & Söhne Kaliber 48 Nr: 203780”
  • “Ankerwerk mit Schwanenhals-Feinregulierung”

Military Association and Provenance

The source characterizes this object as a rare military artifact from the Second World War.

The item is accompanied by a wooden display box, which serves as a container for the watch.

Evidence for this section
  • “Insgesamt wurde das Model B-Uhr Kaliber 48 nur 5.072 mal von Lange & Söhne an die Kriegsmarine geliefert.”
  • “N u r für den U-Boot Einsatz hatte die Kriegsmarine diesen Uhrentyp mit Leuchtzifferblatt bestellt”
  • “Das herrliche Stück (Militär)Uhrengeschichte läuft an und durch”

Open research questions

  • What specific archival records confirm the production dates for the Caliber 48 serial number 203780?
  • Are there contemporary records confirming the specific number of these observation watches delivered with fluorescent dials versus standard dials?

Source evidence

Recorded claims and source quotations for A. Lange & Söhne U-Boot Beobachtungsuhr Kaliber 48
FieldSource-reported valueSource quotation
MakerA. Lange & Söhne“A. Lange & Söhne”
MovementCaliber 48“Kaliber 48”
Serial Number203780“No. 203780”
Case Diameter60mm“Gehäusedurchmesser: 60mm”
FeaturesFluorescent dial, power reserve indicator, decentralized seconds“U-Boot-Ausführung mit fluoreszierendem Zifferblatt, Gangreserve-Anzeige und dezentraler Sekunde”
EscapementAnchor escapement“Ankerwerk mit Schwanenhals-Feinregulierung”

Visible details

  • Fluorescent dial with Arabic numerals and power reserve indicator at the 10 o'clock position
  • Decentralized seconds register at the 3 o'clock position
  • Blued steel hands for hours, minutes, and small seconds
  • Wooden storage box with a metal plaque inscribed 'Lange u. Söhne Glashütte'

Research qualifications

  • The auction description does not provide a specific date of manufacture beyond identification with World War II
  • The auction description states that timekeeping accuracy has not been tested

Photograph identity and source facts were screened before import; rights clearance remains pending.

Consulted source

A. Lange & Söhne U-Boot Leuchtzifferblatt B-Uhr Kal 48 Kriegsmarine WK2

Reviewed 2026-11-02 · Record e3e4434237

Terms in this record

Glossary explanations for terms named in this object’s record.