Complex sentence: On 18 August, Admiral Scheer attempted a repeat of the 31 May operation; the two serviceable German battlecruisers--and--supported by three dreadnoughts, were to bombard the coastal town of Sunderland in an attempt to draw out and destroy Beatty's battlecruisers.
Split into simpler sentences: On 18 August, Admiral Scheer attempted a repeat of the 31 May operation. The two serviceable German battlecruisers, and, supported by three dreadnoughts, were to bombard the coastal town of Sunderland in an attempt to draw out and destroy Beatty's battlecruisers.