Client: Watford Borough Council
Architect: tp bennett LLP
Principal contractor: TSP
Structural engineer: AECOM
Steel fabricator: Nationwide Structures Ltd
Tata Steel products: Celsius® 355 Elliptical Hollow Section
Year: 2014
Images: Courtesy of AECOM

The challenge

A bold design was needed to draw in new visitors and create a thriving retail environment. The council decided to utilise recycled shipping containers as a cost-effective way to create an open and contemporary market space. This posed several challenges for the design and construction teams. The two-storey design meant strengthening work would be required throughout the structure of assembled containers.

An efficient but attractive solution was required for the steel portal frame which would be on view, supporting the roof. The cramped, urban site with a complex, sloping topography posed another challenge – requiring carefully detailed groundworks to support the containers and allow easy access for shoppers.

The roof design was regarded as pivotal in creating a functional but inviting space. A restricted budget of just under £2 million and a tight one-year delivery schedule posed additional project challenges.

The solution

By the latter part of 2013, the market design had been fine-tuned. Work began on procuring long-lead items including 42 recycled shipping containers, supplied by Adaptainer. Working with specialist roof fabricator, JJ Carter, AECOM also developed its concept for a stretched fabric canopy roof.

AECOM came up with the idea of using elliptical hollow section for the portal frame. Tata Steel’s Celsius® 355 Elliptical Hollow Section is used in the same size, 400mm x 200mm, for all of the columns and beams, irrespective of span.

Tata Steel liaised closely with AECOM to ensure that requirements for the Celsius® 355 material were met on time and in full.