Complex sentence: Her skipper, Mengersen, was ordered to shadow and report, but during the day also the first Western Approaches escort, the destroyer "Viscount" (Lt.Cdr MS Townsend), arrived from OB 251.
Split into simpler sentences: Her skipper, Mengersen, was ordered to shadow and report. During the day, the first Western Approaches escort, the Royal Navy destroyer under Lieutenant Commander M. S. Townsend, arrived from OB 251.