Great Britain Share Certificate The Grand Ship Canal 1827 (Intended Ship Canal from London to Portsmouth), certificate for 20 shares. Fine illustration of Ocean sailing ship being towed along the intended ship canal by Steam Tug, Unissued share certificate complete with counterfoil, in clean condition. Note: An interesting example of what might have been. Sir John Rennie in 1811 surveyed this intended Ocean Ship Canal for "The Grand Southern Canal" promoters. Later for "The Grand Imperial Ship Canal" promoters in 1825 proposes, with his brother, "a ship canal from London to Portsmouth, capable of conveying Line of Battleships and the largest Merchantmen" 86 miles long, 300 feet wide and 24 feet deep. The route was to be via Guildford, Loxwood and the Avon Valley. The cost was estimated at Seven Million Pounds