The Seiko Corporation, through its Seiko UK Ltd. subsidiary, began supplying British Forces with wristwatches in the mid 1980's and continues to do so as of this writing. According to British Military Seiko expert, Ian Fogden, there have been only 3 issued Seiko brand chronographs. Although there is also a rare yellow-dialed "Vulcan" chronograph from Seiko that is reported to have been used by Vulcan bomber crews, these rare watches do not carry issue markings. According to Seiko UK Ltd. They were most likely a one-off acquisition by "local purchase order" and not Ministry of Defence (MoD) issue watches in the usual sense.
This review focuses on the three Seiko chronographs that are known to have been Ministry of Defence (UK) issue. At the end of this review is an excerpt from an on-line report by Seiko expert Ian "Foggy" Fogden on the mysterious Vulcan Seiko.Gen. 1 RAF-issued Seiko chronograph
The first RAF-issued Seiko chronograph ( Gen. 1 ) was procured from Seiko UK and issued primarily to Royal Air Force pilots and navigators from October 1984 until November 1990. According to documents I have received from Seiko, 11,307 pieces of this Gen. 1 model were supplied by Seiko to the British Armed Forces.
This Gen. 1 chronograph was contained in a stainless steel case. It carries the highly-regarded, 15-jewel, quartz 7A28 Seiko movement.
As you can see in the above diagram, this Gen. 1 model has three pushers and has all the usual chronograph functions including: split times and 1/10 sec timing, as well as second and minute indicators up to 30 minutes.
A wonderful idiosyncrasy of the Gen 1 chronograph occurs with the register at the 3 o'clock position. This sub-dial measures tenths of a second actively until 10 minutes have passed. At this point the register stops actively measuring time, even though it keeps track within the movement. Once the chronograph is stopped the hand will move to the correct position indicating the tenths of a second that have elapsed. I suppose this was a power saving feature, but it is puzzling until you learn what is going on.
The dial has luminous markers as a result of the application of Promethium 147, a mildly radioactive emitter. The case measures 37mm across, excluding the crown and pushers, and has an inter-lug width of 20mm. Fixed strap bars are used as required by the MoD standard. The crystal is mineral glass and although Seiko no longer carries the original crystal (p/n 300WF0GN00) they have cited reference p/n 300P04HN03 as a replacement.
