Complex sentence: With this obstacle successfully negotiated, "Irresistible" and "Emerald" attacked the anchored Spanish frigates broadside to broadside and the action lasted an hour and a half, with the Spanish ships taking much the worst of the damage.
Split into simpler sentences: With this obstacle successfully negotiated, "Irresistible" and "Emerald" attacked the anchored Spanish frigates broadside to broadside. The action lasted an hour and a half, with the Spanish ships taking much the worst of the damage.