Complex sentence: It equipped the Type 22 frigates HMS "Brilliant", and the Batch 2 Leander class frigate, which were assigned "goalkeeper" duties, to provide close anti-aircraft defence of the carrier task force.
Split into simpler sentences: It equipped the Type 22 frigates HMS "Brilliant", and the Batch 2 Leander class frigate. These ships were assigned "goalkeeper" duties, to provide close anti-aircraft defence of the carrier task force.