RAF, Triangle Dial Without T
Mark XI 6B/346 — RAF, Triangle Dial Without T
From 1952 a luminous triangle replaced the 12 and a shorter, thicker squared-off hour hand was fitted for quicker reading. Radium lume, so no tritium mark above 6. Collectors call it the “No T” dial.
At least 7,400 IWC watches for the RAF; IWC records identify more than 8,000 military movement numbers, with about 600 more thought to await confirmation (Horological Journal 2004).
Identifying details
- Military caseback engraving
Issue markings on the caseback, e.g. stock number, broad arrow, issue number and year.
- Military issue
Issued to armed forces.
- Broad arrow on dial
British government-property broad arrow printed on the dial (also struck on case and movement).
- Triangle at 12
Luminous triangle in place of the numeral 12.
- Soft-iron inner case
Soft-iron inner case and dial forming a cage that shields the movement from magnetic fields.
Variants of 6B/346
Reference overview →| Variant | Production |
|---|---|
| RAF, White 12 Dial | 1949–1952 |
| RAF, Triangle Dial Without TCurrent | 1952–1963 |
| RAF, Encircled T Dial | 1963–? |
| RAF, Encircled T Dial · Encircled T, Hooked 7 | Undated |
Case & movement
- Reference
- 6B/346
- Production
- 1952–1963
- Case material
- Stainless steel
- Case diameter
- 36 mm
- Crystal
- Acrylic, held by a screwed retaining ring
- Movement
- Manual winding
- Date
- No
- Caliber
- IWC 89
Dial, bezel & hands
Movement
IWC 89
Albert Pellaton’s hand-wound centre-seconds calibre with indirect seconds drive and a Breguet hairspring. The Mark XI version stops the seconds for synchronisation. Early batches had no shock protection; later ones were fitted with Incabloc.
Manual winding · Introduced 1946 · 18,000 vph · 17 jewels
Read more
- Time Spec: The Mark XIRead more at Worn & Wound (opens in a new tab)
- ‘Man is Not Lost’ – an Account of the Mk 11 Navigational WristwatchRead more at Horological Journal (British Horological Institute) (opens in a new tab)
- Flying Legend: IWC Pilot’s Watch Mark 11Read more at Revolution (opens in a new tab)