"We wanted it to be an immersive experience with every last detail taken into consideration," he told Dezeen.
"For me a collection called Underground featuring iconic moquette designs predominantly used on the London Underground had to be presented on a tube carriage."
The studio re-paintied the entire exterior in alternating blocks of mint and soft pink, with the windows and lights covered in gels of the same colours. This palette is repeated on the inside to create the coach's standard class section.
"All the graphics were redesigned in our colours and carefully installed to protect the original posters and maps underneath," explained Mould.
"The handrails were covered for protection before being painted and we installed matching vinyl flooring."
Stylist Hannah Bort worked out the details, turning plastic grab handles into gold brass hoops, while a team of upholsterers and carpenters decked the seats out in Kirkby Design's Underground Vol. II fabric collection.
Each design in the series of seven upholstery velvets presents a modern take on original archive prints from the London Transport Museum.
"We chose velvet as it was the most similar in quality to the original wool moquette. Mouqettes are very tough and resilient fabrics and too coarse for interiors."
"Velvet seemed a more tactile alternative while achieving a similar aesthetic," said Mould.
Hidden behind heavy curtains, again in velvet, the first class section features a slightly darker, teal blue and coral palette.
Here, plush carpet is laid and wooden tables are topped with brass art deco lights to evoke an Orient Express-style nostalgia.
Other notable projects from the festival include a space-themed furniture collection by Lara Bohinc exhibited in an 18th-century townhouse, and Dan Tobin Smith's three-year project to capture the inner life of more than 100 gemstones.
Photography is by Luke Hayes.