Complex sentence: Intended as large, fast vessels which had the endurance and speed to operate with the battle fleet, they gained notoriety, and the nickname of "Kalamity class", for being involved in many accidents.
Split into simpler sentences: Intended as large, fast vessels which had the endurance and speed to operate with the battle fleet. They gained notoriety, and the nickname of "Kalamity class", for being involved in many accidents.