In the 1950s innovations in aviation technology made transatlantic travel a more appealing option than ever before. The airline Pan Am quickly emerged as a leader in transatlantic travel by jet plane.
With the unprecedented success that met the introduction of the Rolex Sports models, it came as no surprise when the world’s largest airline, Pan-Am, commissioned a watch to be designed with features specific to its needs, enabling their pilots to keep track of time in two locations.
In conjunction with Pan-Am’s Captain Frederick Libby (a decorated World War II veteran and one of the airline’s most respected navigators), Rene-Paul Jeanneret devised the concept of a watch with an additional hour hand which revolved once every 24 hours and a rotatable bezel marked with those same 24 hours. Hence, the GMT-Master was created.
Although the watch had been made to Pan-Am requirements, many other pilots came to depend on the watch, particularly military pilots. They kept the rotating bezel at “12″, thereby enabling the watch to give them both civilian and military (or 24 hour) time. Among the pilots who came to rely on the GMT Masters most were those chosen by NASA to fly the North American X 15.
While it had been the introduction of the Boeing 707 that had caused Pan Am to commission the GMT Master, eventually it was the people who flew on them as passengers who became the main customers for the watch. With the introduction of jet travel, many people were now travelling between countries and of course between time zones. For these new international travellers the GMT Master was the answer to their prayers.
In 1954, the first GMT Master (ref. 6542) was launched. This model was very distinctive, with Mercedes hands and an extra hour hand had been added which was clearly differentiated by the triangle at the tip. Instead of the usual metal bezel insert, there was a special insert of transparent acrylic which had twenty-four hour markings printed on its underside. This material was chosen to cut down reflectivity and avoid blinding the pilots.
This acrylic bezel insert was the first item to be changed, in 1956, giving way to a metal insert with the numbers now screen-printed. These new bezels were less likely to crack than the earlier plastic ones but were much more likely to fade in bright sunlight.
The original plastic bezel inserts were luminous and it seems that the tritium used to paint them had somehow become contaminated with Strontium 90. Once the problem was fixed, Rolex made sure to confirm to its customers that the model was safe for use.