Complex sentence: Normally, the firebox of a steam locomotive has a semicircular top to match the contour of the boiler, however, the Belpaire firebox has more of a rectangular shape, making a locomotive equipped with one easy to spot.
Split into simpler sentences: Normally, the firebox of a steam locomotive has a semicircular top to match the contour of the boiler. The Belpaire firebox has more of a rectangular shape, making a locomotive equipped with one easy to spot.