The London to Portsmouth route was to be completed by the Portsmouth and Arundel Canal, in which Wyndham and the Cutfields, who also held many shares in the Arun Navigation, were both significant subscribers. This was authorised by Act of Parliament in 1817, and an agreement was reached that the Arun would be improved to aid through traffic. Nevertheless, no work commenced on the Arun until the proprietors were sure that the Ford section of the new canal would actually be built. Once they were convinced, they obtained an Act of Parliament in May 1821, and the engineer James Hollingworth oversaw the improvements, which were completed in mid-1823. The work involved improving the depth and width of the channel, and some alterations to bridges and locks to make their size more uniform. The company borrowed £3000 to finance the work, which cost around £5000 in total. The loans had been repaid by 1831, and the work allowed barge sizes to be increased from 30 tons to 40 tons, with the result that business improved.