As built, the staircase locks were 180 feet (55 m) long, rather than the 170 feet (52 m) of the single locks. The final two were ready by the end of 1811. By June 1809, three of the locks had been completed, and although completion of the flight was expected in 1810, there was a shortage of labour, and only three more were finished. To provide rubble-stone to build the locks, a quarry was opened at Corpach Moss. Consequently, cast iron swing bridges were used, and both the road and the railway at the foot of the flight cross bridges of this type. On the Forth and Clyde Canal, low level crossings were carried over the canal by bascule bridges, but Telford and Jessop rejected this arrangement for their canal, as they thought the risk of masts being damaged by them was too great. It was decided to arrange the locks in clusters to reduce the cost of the project, and so Banavie was chosen as the site for eight locks.

It was intended to build the locks 162 by 38 feet (49 by 12 m), with smaller locks beside them through which boats carrying up to 200 tons could pass, but after consideration of the size of 32-gun frigates and ships which traded with the Baltic, the size of the main locks was increased to 170 by 40 feet (52 by 12 m), and the smaller locks were omitted. There were two resident engineers the one covering the southern section, including Neptune's Staircase, was John Telford, who was no relation to the principal engineer. Telford was appointed as principal engineer, with William Jessop as consulting engineer. An Act of Parliament obtained in July 1803 established a board of commissioners to oversee the work. He suggested that the construction of public works would provide employment, and would also help to develop industry, fishery and agriculture. The Caledonian Canal was conceived by the engineer Thomas Telford after the government asked him to look at measures which might stem emigration from the Highlands. The base plinths of the original capstans can still be seen, although the capstans themselves have been removed. With the advent of hydraulic rams and push-button control, transit times through the flight have been reduced from just over half a day to 90 minutes. There were 36 capstans on the flight, and 126 revolutions were required for a boat to travel up or down the complete flight. Each gate leaf had two capstans, one to open it and another to close it.

Prior to mechanisation, the locks were operated by capstans, each with four poles, which had to make seven full revolutions to open or close a gate.

a dropping craft to pass a rising craft on the same fill/empty cycle. They usually operate on an 'efficiency basis' that is, they try either to fill each cut with ascending boats or with descending boats, or to allow for passing, i.e. The current lock gates weigh 22 tons each, and require a team of at least three lock-keepers to operate the staircase. It consists of eight locks, each 180 feet (55 m) by 40 feet (12 m), and it takes boats about 90 minutes to pass through the system. It is the longest staircase lock in Britain, lifting boats 64 feet (20 m). Neptune’s Staircase at Banavie, near Fort William just north of Loch Linnhe, is kept by Scottish Canals.

Neptunes staircase