Complex sentence: On 23 January 1942, No.615 Squadron (County of Surrey Squadron) Auxiliary Air Force, arrived from Angle aerodrome, equipped with Hawker Hurricane fighters, operating there until 17 March when the squadron moved by train to Liverpool Docks, boarding the Johan van Oldenbarnevelt.
Split into simpler sentences: On 23 January 1942,615 Squadron (County of Surrey Squadron) Auxiliary Air Force, arrived from Angle aerodrome, equipped with Hawker Hurricane aircraft. They operated until 17 March when the squadron moved by train to Liverpool Docks and boarded the Johan van Oldenbarnevelt.