SINN Spezialuhren zu Frankfurt am Main went a step further with two watches from the 756 and 900 series and had them tested under extreme conditions by DEKRA at the Technology Center in Klettwitz (Brandenburg). The test specification: impact speed of 64 km/h with up to 81 g (1 g = 9.8 m/sec (3.2 ft/sec)2) on the wrist of a dummy in an automobile body. The automotive specialists at DEKRA had never performed a test like this before, and it remains unique to this day.
The DEKRA testing center was the location of a watch test that remains one of a kind. SINN Spezialuhren is known for using unconventional technologies and materials in manufacturing its watches. Thus, one of the most unusual stress tests carried out under standardized conditions at DEKRA was ideal for Brand's purposes.
|Sinn Model 756 duochronograph|
A watch on the wrist of a 75-kilogram "human" dummy had never been launched from the compressed air catapult before. For real human passengers in an automobile, the simulation test would correspond to acceleration forces of up to 81 g at a speed of 64 km/h. Without the use of safety belts and airbags, the chance of survival in a real crash would be zero.
|Sinn Model 900 multifunctional chronograph|
Then the countdown started as if for a spaceship and the technicians left the launch ramp. Buckled up in his seat and wearing his SINN watch, the dummy looked rather lonely. The final launch preparations got underway behind a thick glass window in the control center above the test hall. Behind sound-insulated walls, a compressor filled a set of air tanks to 150 bar. The catapult was held in front of the launch jet with several brake cylinders connected in series.
With a loud bang, the catapult was released.The pressure mounted as the countdown continued – ten seconds left. With a bang, the dummy and his watch were flung into the safety belt in 60 milliseconds. The dummy's upper body shot forward like lightning. The arm with the watch waved through the opening of the side window. After 20 meters,the vehicle body braked to a stop. The SINN team with SINN's CEO engineer Lothar Schmidt and the technical developers Dr. Wolfgang Schonefeld and Dr. Ronald Boldt (CEO of SUG) approached the catapult. Would they find a "time bomb" ticking there, or merely an extremely durable watch? By comparison,aerobatic and jet pilots are exposed to acceleration forces of "only" 11 g. The DEKRA test was much tougher!
The initial inspection revealed that the dummy was fine, the watch that was knocked against the car body showed no external signs of wear, the spring bars of the watch band were just as straight as before the launch, and the watch was running. The subsequent measurement on the timing machine showed how the mechanical movement withstood acceleration forces up to 81 g. Compared with the values recorded before the test, the new measurement data were practically identical.
After the second test with the 900 model, the DEKRA and SINN teams recognized that this was no"time bomb" ticking away, but a perfectly functioning, extremely robust mechanical wristwatch. Here as well, there were only minimal changes in the amplitude values in the range of hundredths of a second. In addition to robust watch mechanisms,hardened cases and sapphire crystal glass surfaces also contribute to the enduring beauty and reliable functionality of these watches in everyday use. DEKRA has officially certified this unusual watch stress test.