Complex sentence: BAE's original working baseline for the Type 26 design was a vessel of 141 metres long with a displacement of 6,850 tonnes and an "in service date" of 2021.
Split into simpler sentences: BAE's original working baseline for the Type 26 design was a vessel of 141 metres long with a displacement of 6,850 tonnes. With an "in service date" of 2021.