Seiko had produced railway watches since 1929, with the Type 19 becoming famous across Japan and seen in every railway cabin. It had been updated over the years, notably from 7 to 15 jewels and with hacking seconds, but was outdated by the 1970s. The Type 19 was discontinued in November, 1971. In 1972, Seiko began producing a railway watch, the Type 61RW using Cal. 6110A, and this was the standard until 1980.
As Seiko gained confidence in their quartz movements, they began developing a quartz model, the Type 38RW. But this was not adopted and production began and ended in 1976. Cal. 7550A was a more modern third-generation quartz movement and was adopted for the next railway watch. Despite offering lower accuracy than Cal. 3870A (15 seconds per month rather than 10), Cal. 7550A boasted longer battery life and cheaper construction.
Type 75RW was introduced in January 1978, the same month the Type 61RW, with sales starting in March. Another mechanical model, Type 63RW, was also introduced in August of that year. The National Railway selected the quartz Type 75RW in 1980, and the mechanical offering was discontinued. Production of the quartz Type 75RW continued until 1987, when a high-precision quartz model, SVBA001, was added. This would be the final Seiko Japan National Railway watch to date.