 The canal was commissioned in 1791 by local landowners and businessmen and built between 1791 and 1808 , during the Golden Age of canal building , at a cost of £ 127 @,@ 700 ( £ 8 @.@ 93 million today ) . Originally designed for narrow gauge boats , during its construction the canal was altered into a broad gauge canal to allow an ultimately unrealised connection with the Leeds and Liverpool Canal . The canal company later converted into a railway company and built a railway line close to the canal 's path , which required modifications to the Salford arm of the canal . 
