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BIM at New Street

Mace is working as delivery partner with Network Rail for the redevelopment of Birmingham New Street Station. Paul Dalton, senior project manager for Mace, writes on how the £600m project is harnessing BIM.

From our work across the industry, we’ve often found that rail’s uptake of BIM has largely been in line with other areas of construction: it’s a slow burner that will ultimately completely change the way we build.

The theory is well-established, but as we move from analogue to digital on our building sites, we should be continually asking ourselves how we can use BIM to drive productivity, efficiency and safety. Design has all too often been the focal point of our ability to create BIM models, while it’s the practical advantages that typically have the most to offer.

Model behaviour

At New Street, we’re delivering a flagship transformation for the second city’s largest and busiest station. First opened in 1854 and rebuilt in the early 60s, it’s a huge and sprawling site – with 12 platforms serving 32 million passengers a year in the heart of Birmingham. With the redevelopment programme (due to complete in 2015) that capacity will rise to 52 million.

This will include a 10,500m2 concourse and signature atrium as well as a new shopping centre, called Grand Central, with a 23,000m2 John Lewis, all of which will be added to the station as it remains operational throughout.

Limiting disruption for passengers is paramount. So too is allowing the retail and commercial units to stay as close to ‘business as usual’ as possible – enabling the station to continue to operate, generate revenue and serve its passengers throughout this comprehensive redevelopment.

It’s a complex programme and the first step was to use BIM to map out the original station. That allowed the team to firstly understand what there was to work with, and secondly to identify any gaps we had.

It meant we could spot any issues from the original drawings – limited loads or degraded structures – and make sure they were clear from the outset.

With that as a benchmark, BIM has been used from the earliest stages of the project to map out every step of the works – visualising the sequences, and allowing us to identify issues before they get to site. It includes, for example, all of the temporary works we have. Clearly, they’ll never be part of the final design but they’re crucial to the delivery of the project – and it’s delivery that we’re really using BIM to manage.

Ultimately, it’s become our planning tool. Network Rail has been hugely important in that, and the model is linked to our master programme so that you can pick any date in the programme and the model will show you its status and planned activity. That is hugely important, and provides a shared interface with  our client and our supply chain that can be used at planning meetings to highlight with our client amd our supply chain that can be used at planning meetings to highlight clashes, scope gaps or for safety reviews.

Room for innovation

One of the most valuable aspects of the model has been the scope it gives us for scenario planning. It allows us to quickly model proposed approaches and test different ways of working on specific aspects of the scheme. Essentially it provides a platform to experiment in a safe environment, and helps to drive lean construction and avoid waste.

There have been tangible benefits. When we set out, the delivery schedule for the atrium was 12 months. By looking at different approaches we reduced it to six.

Likewise, part of the scheme will require us to move an existing 120m pedestrian tunnel and relocate it within the station. It consists of some 30 prefabricated sections, and moving it was originally going to be a two week programme. It will now take just 53 hours – purely by modelling different scenarios and refining the process. All of which makes a huge difference when you’re asking your client to close an area of the station for a weekend rather than a fortnight.

BIM lessons learnt

One of the biggest things I’ve taken away from the scheme at New Street has been the need for BIM to be accessible. It needs to be practical for subcontractors, and not require unrealistically powerful IT hardware. We’ve found it to be key as a reporting tool, too. Conventional drawings and assessments can be fairly unclear for non-technical stakeholders. So we use BIM for the walkthrough, and that makes the whole process much more transparent and understandable.

BIM is also bringing new skills onto site. One of the big reasons we’ve been able to maximise our engagement with BIM is that we give it dedicated resource. We have a member of our team with software design experience – rather than purely a construction background – and that has been pivotal in getting the right information from our package and project managers, and overlaying it onto the model.

Moreover, it helps us use that information intelligently. Our team has been able to export the BIM model to iPad apps, for example, and make it accessible across the site. Those skills are out there in our economy – especially with younger, digitally-savvy apprentices and graduates that have grown up with IT, and it follows logically that if BIM changes the way we build, it should also change the complexion of our teams. Having people with diverse skill sets prevents the rate of innovation surrounding our industry from outstripping what we’re doing on site, and that can only help us to maximise what we can do with the models we invest our time in building.

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