It was designed by Mott, Hay and Anderson and fabricated by the famous bridge building firm of Sir William Arrol & Co. at their Dalmarnock Ironworks in Glasgow (they also built the famous Forth Rail Bridge and the steel structure of Tower Bridge in London).
This passage describes the origin of a structure, highlighting its design team and the company responsible for its fabrication. It emphasizes the expertise of Sir William Arrol & Co., known for their significant contributions to bridge construction.