Complex sentence: In the US, this type is known as the Union after the only US railroad to purchase locomotives of this arrangement, the ten Union Railroad 0-10-2 locomotives built for the Union Railroad in the Pittsburgh, Pennsylvania area.
Split into simpler sentences: In the US, this type is known as the Union after the only US railroad to have new locomotives built in this arrangement. These were ten 0-10-2s built for the Union Railroad in the Pittsburgh, Pennsylvania area.