Tata Steel UK, part of the global steel giant Tata Steel, has a long-established, in-depth knowledge of steel construction. A prolific innovator itself, it is helping to drive the digital transformation of the industry through collaboration with innovative technical SMEs. It saw an opportunity to transform the production and installation of steel trusses used in the superstructure of long-span industrial buildings, to digitise its offering and improve the productivity of these large-scale projects.

Creating large steel truss frameworks required for large scale industrial construction projects is a costly and time-consuming process because trusses tend to be designed on a bespoke basis for each structure and the manufacturing process is largely a manual process. Despite the growth in modern methods of construction, steel truss manufacture has seen very little change or innovation in recent years. In fact, within the construction industry as a whole, 92% of the sector use bespoke methods rather than mass customisable approaches, with only 17% of the industry using automated processes. The project partners saw an opportunity to improve the design and manufacture of steel trusses through the adoption of design for manufacture and assembly principles and the use of advanced manufacturing methods and automation.

The application of modern methods of construction will transform steel-truss assembly. The FASTtruss demonstrator tests the most challenging part of automated truss manufacture, robotic fixturing and welding. The project intention is to show that automated design and manufacture of steel trusses is both feasible and cost-effective, as well as additional benefits such as increased productivity, predictable lead times, improved construction programmes and safer working conditions. Initially designed for warehouse construction, the method can be adapted for long-span structures in the public and private sectors, including schools, retail parks, leisure centres and airport terminals. And improved precision and productivity means better quality buildings for end users.

Driven by the knowledge that 90% of large scale builds still use manual, bespoke approaches, Tata Steel UK saw an opportunity to improve productivity and reduce costs in steel truss assembly. It knew, though, that it needed to demonstrate the economic viability of changing such a long-established process and to do so must develop a working proof of concept. The support from the Transforming Construction Challenge meant it could engage the right partners to create a viable robotic demonstrator.

Aware that it required additional industry experts, Tata Steel UK reached out to Design for Manufacture and Assembly (DfMA) architecture expert Bryden Wood and digital manufacturing specialist AMRC to test the theory. The proof of concept started with a detailed analysis of a traditionally built warehouse, and includes the development of appropriate digital design techniques and the small-scale testing of automated robotic manufacturing.

A more manual process ends up costing the industry more through resources, complex production lines and inaccuracies. A more automated, repeatable approach on large-scale projects will save time, be most cost-effective and add value through productivity and precision.

A key challenge for this project is to determine which processes are required for the automated manufacture of FASTtruss, and what is needed from the advanced manufacturing facility to be able to meet the demand for the high variation in trusses required from mass customisation. To be viable, the facility must be able to produce steel trusses in a manner that is more productive and cost effective than the current, traditional approach. Once the team had benchmarked the traditional process on a traditionally built warehouse, the Bryden Wood team developed the FASTtruss design tool. The tool allows designers to customise the design requirements to meet the needs of different buildings, in a simple and structured way. The tool also models and compares thousands of different truss designs to determine the most suitable for a particular building; it then outputs a 3D model of the final design and creates the bill of materials required to manufacture the trusses. The tool has been used to create the 3D prototype design that the AMRC will create in their demonstrator trials. 

The 3D truss model created by Bryden Wood is being used by the AMRC to create a physical prototype of the FASTtruss - Fabrication Automation for Steel Lattice Trusses (FASTtruss). The AMRC demonstrator involves one gantry robot picking and placing parts into a welding fixture, and one cartesian robot welding the parts to form a truss. The AMRC carefully selected the most suitable equipment for the demonstrator, allowing different welding techniques to be trialled and ensuring equipment was suitable for the harsh environment within the welding cell, such as with heat-shielded motors, cables and sensors. The AMRC trials will demonstrate that the manufacture of robotically welded trusses is feasible. Lessons learned from the trials will be used to improve the Bryden Wood 3D truss design tool and develop the FASTtruss manufacturing facility. While a manual process before would have taken months to do this with many more steps, FASTtruss is already showing that this could reduce to hours. And traditionally the accuracy of fitting parts of the lattice that forms the truss is around 10mm-20mm differential when it is done manually. The robotic demonstrator is showing it is around 0.1mm.

Tata Steel UK is the largest steel manufacturer in the UK with a long history within the construction industry and a diverse portfolio of construction products. Bryden Wood is an architecture and engineering design practice with a specialism in Design for Manufacture. The AMRC is a network of world leading research and innovation centres, with a global reputation for revolutionising productivity in the aerospace sector. The AMRC is translating this knowledge for the construction sector, applying digital and data driven process into the construction industry to heighten the impact of digital manufacturing. Tata Steel UK, the AMRC and Bryden Wood have created a team of experts that brings together their specific and in-depth knowledge in steel construction, digital design, DfMA, advanced manufacturing methods, and robotics.

• Advanced Manufacturing Research Centre (AMRC)
• Bryden Wood
• TATA Steel

All three partners have been involved in Innovate UK R&D projects before, and Transforming Construction Challenge brought them together to undertake this feasibility study through the creation of a DfMA design tool and FASTTruss prototype.

The aim of FASTtruss is to make the manufacture of steel trusses more cost effective so that they are a viable alternative to a wider portion of the market. By using advanced automated manufacturing and following DfMA principles, FASTtruss will be in a position to offer a number of benefits, including increased repeatability, faster and predictable lead times, improved erection times and improved worker safety both on and off site. The technologies tested in this project will initially be used for the development of steel trusses for commercial warehouses, for both domestic and export markets. However, the technologies are scalable for a wide range of long-span buildings in both the public and private sectors, leisure centres, airport terminals and industrial buildings. The project will lead to a streamlined one-stop process and will demonstrate reductions in costs and delays, together with improvements in productivity and output. It shifts the skills needs to that of digital and offsite assembly, encouraging new skills into the construction sector. It is anticipated that it will reduce carbon emissions by minimising material use, wastage and rework (thanks to advanced manufacturing methods)

Welding is a hazardous and highly skilled job, and given the ongoing skills shortages within the construction industry, it can be difficult to find operatives with the required skills. This solution calls for a diverse set of skills and roles in construction so could attract diverse talent to the industry. For example, this approach is being applied across Bryden Wood’s work, increasing their team’s headcount. The team are supporting PhD students and investing in more R&D as a result of this project. Three full time roles have been retained thanks to this investment.

The FASTtruss demonstrator uses robots to position and weld steel lattice trusses using the design data generated by the parametric design tool. This eliminates the need for manual handling of large structural hollow sections and manual welding, improving worker safety. The FASTtruss manufacturing facility will learn lessons from the AMRC trials and use similar robotic fixturing and welding techniques. It will also aim to maximise automation for all the other processes required, such as part cutting, grinding, cleaning, painting and shot blasting, to create a continuous streamlined facility.   Tata Steel UK has a significant commercial interest in FASTtruss and it is anticipated that the emergence of applicable data from the demonstrator and the ability for customers being able to see the prototype in action this will increase and develop further.

 A significant element of the sector use bespoke methods for steel truss fabrication and assembly, rather than a customisable approach. The robotic automation of a steel truss system will significantly reduce overall production times. FASTtruss and the parametric design will reduce overall pre-delivery time and, when combined with DfMA, suggests an overall time saving of up to 10% could be achieved for the developer. This model will be able to design 2,000 types of trusses, assessing implications, errors and the best options according to project plan. FASTtruss will utilise 100% UK supplied steel Structural Hollow Sections manufactured by Tata Steel UK.

Productivity
The design and optimisation tool designed for FASTtruss is quick and easy to use, allowing design engineers to customise the variables to suit the requirements of each building. The tool generates and compares 2,000 different truss designs, ranking these against various criteria to arrive at truss design that is optimised for that building. The design tool takes only one to two hours to run, providing significant time savings during the design stage.

Time
The automated production facility will be streamlined to maximise efficiency, parts will flow seamlessly and continuously through the production line which will use robotics where possible to increase productivity. FASTtruss and the parametric design will reduce overall pre-delivery time and, when combined with DfMA, suggests an overall time saving of up to 10% for the developer.

Trade Gap
FASTtruss will utilise 100% UK supplied steel Structural Hollow Sections manufactured by Tata Steel UK. 

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