Birmingham New Street Challenges Overcome

TDS has taken on one of its most complex and challenging projects to date – detailing the cladding and support frame for the Southern Hub ticket office at the end of the new Navigation Street footbridge, which forms part of the multi-million pound Birmingham New Street Station Gateway Plus redevelopment.

Our work began in January 2016 and the project is due to commence construction next month. It is fair to say that it has not been an easy journey, but now as it nears completion we can look back at the challenges and the ultimate success of the project. There are two elements at the centre of the project that have complicated the process from the outset.

Firstly, TDS, as steelwork specialists have relatively little experience with aluminium products. The supplier and fabricator commissioned for this element of works, are lightweight metal framing specialists and getting to grips with modelling systems we’ve not encountered before set up the initial big challenge. However, after adapting our existing knowledge and regular design meetings with them we overcame this obstacle.

Secondly, since the conception of the project, The Southern Hub has passed through the hands of several designers. It was clear early on that the twisting, curving nature of the structure was designed to complex geometry and this original setting out would be crucial for the development of the cladding subframe. The original setting out could not be obtained meaning that most of our model work has been done with very little tangible setting out information and in a purely 3D environment, modelling to other parts within the model rather than to a defined set of coordinates or grid lines.

These initial complications could be overcome with time, but The Southern Hub design has been a minefield of complications, just as we managed to diffuse one issue, another would crop up. The predominant concern when it came to draughting was with the cladding panels and the general shape they form. The entire roof twists and turns but this twist is present in each individual cladding panel to varying degrees. We were asked to take the twist out of the cladding panel but this was impossible without the original setting out so the decision was made to design the subframe to suit the twist but provide the cladding panel flat, and let the panel take the correct shape when fixing it to the frame. However, a sample panel had to be created to determine if the aluminium cladding sheet could deflect by the amounts required. Together with the design team and our supplier and fabricator, we found a way of making this design practical whilst maintaining its architectural integrity.

On top of finding the answer to that dilemma we also had to solve the puzzle of how to fix a sloping cladding panel and subframe to rafters that are not parallel to the cladding and rafters that do not line through with each other. This was a round peg into a square hole scenario. Creative ways were found to use standard and bespoke products to achieve the fixing tolerances required. It was not a simple task but something that has taken a huge amount of time and has ultimately been successful.

The whole project has really been an exercise in trial and error modelling, the skill of our experienced TDS draughtsman leading the project has been key. It hasn’t been an easy journey, but every problem encountered has been overcome and the final detailing maintains architectural appearance whist ensuring that the construction of the subframe is feasible.