Omega Railmaster
The original OMEGA Railmaster was first launched in 1957 – the same year as the now legendary Speedmaster model – as the successor to a watch created for the British Royal Air Force in 1953. Designed specially for scientists, technicians, electricians and railway workers, or anyone else working in or around powerful electric currents, it had a special double antimagnetic case to protect the watch movement from the harmful effects of these electrical fields. The outside case was made of Staybrite stainless steel, with a polished bevelled bezel, polished solid enveloping lugs, reinforced crystal and a screw-in back with O-ring gasket to ensure water resistance. The inside case consisted of a protective cap, a casing ring and a 1mm thick dial (as opposed to the 0.4mm for a standard dial) made of soft iron, which formed a screen against magnetic fields of over 900 Oersted in any position, as opposed to 60 Oersted for a conventional antimagnetic watch.
Omega Speedmaster
The Speedmaster's history goes back to 1957 when it was introduced as a sports and racing chronograph, complementing OMEGA's position as the official timekeeper for the Olympic Games.The "Speedmaster" name was chosen for its tachymeter scale bezel and following the OMEGA convention used for other models like the Seamaster - initially the Speedmaster was part of the Seamaster line - and the Railmaster.
Omega Seamaster
At the time the Seamaster was introduced in 1948, standard watches were extremely susceptible to water damage from even a dip in a sink or tub. The Seamaster was created as a line of standard dress-style watches which were 'waterproof' (as they called them then) suitable for swimming and other light water activities. Their water resistance then is about comparable to a 10 to 30 meter rating today. The now common diver's watch style was unknown at that time. Ten years later in 1958 Rolex introduced the Submariner, really starting the popular market for the sports/diving style of watch (though other brands did have such watches even earlier). A few years later, OMEGA added the comparable sportier models that were designed for even deeper water activities like diving that need a rating of 100 to 300 meters. They maintained the Seamaster name because of their water resistant designs. This split the Seamaster line of water resistant watches into both classic dressy and more rugged sporty styles.
Omega Globemaster
The Globemaster name was the result of a trademark conflict in the United States, resulting in watches from the Constellation line being renamed as a Globemaster, however, this issue was resolved in 1956. Many of these watches simply had the Constellation star on the dial. The name stuck in future lines following resolution of the trademark issue.
