With the help of AutodeskÝs NavisWorks, project contractor Skanska took on major modernisation at two London hospitals and was able to simulate how architecture, structure and building services would come together on site.
Rebuilding and refurbishing any major building is always a complex task with many contractors and services to be managed. But when the building is a hospital, built in Victorian times and now ready to be brought into the 21st century, the complexities multiply. That is the task facing Skanska, the main contractor to Barts and The London NHS Trust as they modernise both their major sites: Barts in the City and the Royal London Hospital in Whitechapel. The trust is committing around one billion pounds to the project, due for completion by 2015. With stakes that high, Skanska needs to keep the project firmly on track.
The company has an excellent record in delivering major building works. It was responsible for 30 St Mary Axe in the City of London, better known as the Swiss Re Building or The Gherkin. To help co-ordinate sub-contractors and the installation of plant and building modules, Skanska turned to the JetStream software package from NavisWorks, now part of the Autodesk family.
ýThe software combines designs from different 3D packages into a single model,¯ explains David Grieve of Autodesk. ýWith support for around 50 different file formats we can bring virtually any project together into one 3D model which the project management team can use to review the design and progress on site.
ýYou can review the design without the need to understand CAD, and use that to see how elements fit together,¯ he continues. ýIt is a four-dimensional package, with main contractors using it to build a timeline of processes. Some will even put up a time lapse camera and compare it with the timeline in NavisWorks.¯
David Throssell, co-ordination specialist at Skanska for the Barts and The London project, concurs. ýWe are now established users of the software to animate how architecture, structure and services will fit together on a project plan. We are now finding new uses for it, and it is clear that we can demonstrate real savings in cost and improve the robustness of our timescales.¯
Throssell quotes a simple example for the Royal London site. The refurbished building needed twelve electrical sub-stations, installed in different places within the building. As project managers, Skanska needed to know that each could be physically delivered to its plant room as well as installed safely when it got there.
ýOne option would be to run factory tests then disassemble the sub-stations, move them into place in parts, then re-assemble and retest them,¯ Throssell explains. ýWe did not want to do that, partly because of the cost ± around ú10,000 for each of the 12 sub-stations ± and partly because of the time it would take on site.
ýUsing NavisWorks we could ÙwalkÝ the delivery route for each unit, and identify where there were problems,¯ he continues. ýIt allows us to specify larger doorways where these would be a problem, and delay finishing some corridor walls, which would otherwise have been too narrow. Thanks to the NavisWorks model we can identify every installation problem and plan them out, making for a smoother job.¯
The same planning benefits are being applied to large pieces of plant, service modules and other equipment. Using the timeline functionality allows Skanska to make the best use of resources, for instance planning to build partition walls as soon as all the large modules have been installed.
But what marks a hospital out as an even more demanding case is the requirement to install highly sophisticated diagnostic systems such as MRI scanners and linear accelerators. These, too, are large pieces of equipment which need to be delivered to their final locations as finished assemblies. Unlike much of the standard building plant, though, they can only be delivered to a finished, clean and dust-free environment.
ýAn MRI scanner is a big piece of machinery that needs to be delivered late in the construction process, preferably after the walls have gone up,¯ says SkanskaÝs David Throssell. ýDemolishing walls on site to get machinery around corners represents a cost and a time over-run, which we need to avoid.
ýWith the complete 3D model in NavisWorks we can quickly create the MRI scanner in its packaging and move it through the virtual world to its final position. In turn that means we can make changes to the design ± raising doors or widening corridors ± to make it work.¯ MRI scanners and the various other large items of specialist equipment required in a state-of-the-art hospital are expensive as well as highly functional, and so the Trust had a separate procurement process for each to ensure they got the best deal in terms of performance and cost. Different manufacturersÝ offerings for each application would, of course, be in their own housings, sometimes differing widely in size. David Throssell and his team at Skanska needed to be sure that the delivery route was clear whichever supplier of machine was selected.
ýWe use NavisWorks for spatial co-ordination between disciplines, but we are taking it much further,¯ he says. ýWe use it to see what we can build before we move plant in, and we use it to see that there is good, clear and safe access for future maintenance and operation. That is what NavisWorks is good at ± giving us a complete view of our project in a virtual world.¯