Complex sentence: Simultaneously, the British III and IV Light Cruiser Squadrons began a torpedo attack on the German line; while advancing to torpedo range, they smothered "Wiesbaden" with fire from their main guns.
Split into simpler sentences: Simultaneously, the British III and IV Light Cruiser Squadrons began a torpedo attack on the German line. While advancing to torpedo range, they smothered "Wiesbaden" with fire from their main guns.