Minol (pronounced mine-ol) is a military explosive developed by the Admiralty early in the Second World War to augment supplies of trinitrotoluene (TNT) and RDX, which were then in short supply. The aluminium component in Minol significantly prolongs the explosive pulse, making it ideal for use in underwater naval weapons (e.g. sea mines—for which it was developed—depth charges and torpedoes) where munitions with a longer explosive pulse are more destructive than those with high brisance.
Typically, four different Minol formulas were used. All percentages shown are by weight:
- Minol-1: 48% TNT, 42% ammonium nitrate and 10% powdered aluminium.
- Minol-2: 40% TNT, 40% ammonium nitrate and 20% powdered aluminium.
- Minol-3: 42% TNT, 38% ammonium nitrate and 20% powdered aluminium.
- Minol-4: 40% TNT, 40% ammonium nitrate & potassium nitrate (90/10) and 20% powdered aluminium.
Since the 1950s, Minol has gradually been superseded by more modern PBX compositions, due to their superior explosive yield and stable storage characteristics. As a result, Minol is regarded as obsolete. Generally, any Minol-filled munitions encountered will be in the form of legacy munitions or unexploded ordnance dating from before the 1960s.