Key Facts
- Year conducted
- 1944
- Commandos executed
- 10
- Total men killed or died
- 13
- Execution date
- 7 July 1945
- Unit involved
- Z Special Unit (Allied)
- Preceded by
- Operation Jaywick (September 1943)
Strategic Narrative Overview
The raiding party, drawn from the Allied Z Special Unit, initially planned to use motorised semi-submersible canoes called 'Sleeping Beauties' to infiltrate Singapore Harbour, but were forced to fall back on Australian-built Hoehn MKIII folboats. The operation was compromised when local Malay authorities discovered the raiding party, alerting the Japanese. Thirteen men, including commander Lyon, were killed in subsequent engagements at various island locations or died of wounds while in Japanese captivity.
01 / The Origins
Operation Rimau was conceived as a follow-up to the successful Operation Jaywick, in which Allied commandos had clandestinely attacked Japanese shipping in Singapore Harbour in September 1943. Originally part of a broader plan called Operation Hornbill, the mission aimed to exploit the proven vulnerability of Japanese-controlled Singapore by deploying small raiding teams with limpet mines to sink enemy vessels. The operation was led by Lieutenant Colonel Ivan Lyon of the Gordon Highlanders.
03 / The Outcome
Ten surviving commandos were captured by the Japanese and transported to Outram Road Jail in Singapore. They were subjected to a Japanese military tribunal on charges of perfidy and espionage, widely regarded as a kangaroo court. All ten were executed on 7 July 1945, just weeks before Japan's surrender. The operation ultimately failed in its objective to sink Japanese shipping and resulted in the loss of the entire raiding force.
Belligerents & Mobilization Analysis
Side A
1 belligerent
Lieutenant Colonel Ivan Lyon.
Side B
1 belligerent
Kinetic Engagement Axis
Scroll horizontally to view full axis. Events plotted relatively.