Complex sentence: She was oil-fired and had a bunkerage of 320 to 370 tons, giving a range of between 3500 nautical miles at 15 knots or 900 nautical miles at 32 knots.
Split into simpler sentences: She was oil-fired and had a bunkerage of 320 to 370 tons. This gave a range of between 3500 nautical miles at 15 knots and 900 nautical miles at 32 knots.