Charles Collett, Chief Mechanical Engineer from 1921 to 1941, greatly improved the works' boiler making and its facilities for working heavy gauge sheet metal.
In 1927 the GWR's most powerful and largest locomotive, the King class, was introduced to become the "flagship" of the GWR fleet.
The Kings had been developed from the Castle Class which, along with the Halls, were the foundation of the GWR's reputation and image.

This was the heyday of Swindon Works, when 14,000 people were employed and the main locomotive fabrication workshop, the A Shop was, at 11.25 acres (45,500 m²), one of the largest covered areas in the world.

During World War II Swindon was once again involved with military hardware, producing various types of gun mountings.
Loco wheel-turning lathes were also ideally suited for making turret rings for tanks.
The works also built landing craft and parts for midget submarines.
Charles Collett, Chief Mechanical Engineer from 1921 to 1941, greatly improved the works' boiler making and its facilities for working heavy gauge sheet metal. In 1927 the GWR's most powerful and largest locomotive, the King class, was introduced to become the "flagship" of the GWR fleet. The Kings had been developed from the Castle Class which, along with the Halls, were the foundation of the GWR's reputation and image.
This was the heyday of Swindon Works, when 14,000 people were employed and the main locomotive fabrication workshop, the A Shop was, at 11.25 acres (45,500 m²), one of the largest covered areas in the world.
During World War II Swindon was once again involved with military hardware, producing various types of gun mountings. Loco wheel-turning lathes were also ideally suited for making turret rings for tanks. The works also built landing craft and parts for midget submarines.
Swindon Works