When Stewart took over less than 250 hands were employed, but within a week he had 2500, and eventually 4000. Rail tracks were laid to all parts of the site and round the perimeter, and material poured in, between 200 and 300 truck loads daily. Riveters were provided with automatic tools to supersede manual work, and their output was quadrupled. Steam hoists replaced human hod-carriers, and bricklayers were shown how to lay from 1500 to 2000 bricks daily instead of their accustomed 400 or 500, a feat that inspired correspondence and a leading article in The Times.

No less than 11,000,000 bricks, 9,000,000 feet of timber, and 17,000 tons of steel were used, and an uncovenanted task was the protection of a main outfall sewer crossing the site: a massive concrete structure was erected—and later put to good use during air-raids in the second world war. In ten months eight of the nine main buildings were ready for use, and the whole task was completed in less than one-fifth of the time originally estimated—a remarkable performance.

An important event during construction was the laying of the foundation stone. Westinghouse himself was prevented from attending by ill-health, but through the good offices of Joseph Lawrence, a director who was also a sheriff, the Lord Mayor of London, Sir Frank Green, was prevailed upon to perform the ceremony. At two o'clock on August 3, 1901, he arrived with the Lord Mayor of Manchester, and after speeches, which included a reference to the combination of American intellect and British capital, the stone was laid. Beneath it was placed one of each coin of the realm so as "to put the undertaking on a sound financial foundation".

It was a gala day for Traffordville said the local press. A banquet was laid out in a marquee erected in 'A aisle', where many had their first experience of American bars and Martini, Manhattan, and Bronx cocktails. The foundation stone may still be seen at the north-eastern corner of the main office building, and eye-witnesses of the ceremony, among them W. Roughton of comptroller's department, are to be found at the works.

The factory covered some 30 acres of the main 100-acre site. The chief buildings, all in use today, ran from north to south on either side of a main avenue with gates at each end. On the west side was the machine shop, known today as the main shop and still one of the largest in the world. This building, measuring 900 by 440 ft, was divided into a number of bays or' aisles', lettered A, B, C, D and E.