Rolex ref 6556 Trubeat

The Rolex ref. 6556 “Tru-Beat” is a very rare 1950s Oyster Perpetual with a mechanical dead‑beat seconds complication (jumping once per second like a quartz), built around the automatic caliber 1040 and aimed especially at doctors for taking pulse readings.

Key characteristics

• Produced mid‑1950s (commonly cited around 1954–1960) in an Oyster case about 34–35 mm in diameter, in stainless steel with classic silver “Tru‑Beat” signed dials.

• Uses the automatic caliber 1040, derived from Rolex’s 1030, with an added dead‑seconds mechanism that converts the normal sweep into a single jump per second at 3,600 visible “ticks” per hour.

Dead‑beat seconds concept

• The seconds hand “ticks” once per second like a quartz watch, but is fully mechanical; the additional train and pallet system stores and releases energy once per second.

• This behavior was marketed to medical professionals and scientists, as the clear one‑second jumps make it easier to count heart rate or perform time‑based observations without a chronograph scale.