Complex sentence: The construction shed at the Cavendish Dock at Barrow was too small for the new design so a new hangar was built at Walney Island, off the west of Barrow.
Split into simpler sentences: The construction shed at the Cavendish Dock at Barrow was too small for the new design so a new hangar had to be built. This was done at Walney Island, off the west of Barrow.