SERVICE RISER, CENTRAL LIBRARY, IMPERIAL COLLEGE-LONDON
Universities and Colleges throughout the UK have seen a consistent increase in the number of students attending full time courses. This has seen a need for upgrading many of their facilities to be able to offer a wider range of courses and also to be able to compete against other educational establishments to maintain their attraction to the influx of new students each year.
Existing facilities are typically well established on existing sites which are often land locked and desperately short of space for further development.
None more so than Imperial College, London. As one of the oldest Universities in the UK and located in the prestigious district of South Kensington in Central London, there is very little space for development left on the site and development land in the region commands premium rates. When considering how to add to the existing facilities it was decided “the only way is up” as they say.
Imperial College London’s Central Library Building Project Phase 2 aimed to improve cooling and ventilation systems throughout the Central Library. The existing services within the library levels 4 & 5 also needed a total revamp. Also, to accommodate all of the new Chilled water & Air plant required to serve the library, a new roof top plant deck area and plantroom was constructed. Added to this, the library needed to stay operational throughout the redevelopment of the site.
An essential part of the redevelopment involved the construction of a very congested service riser which ran up through the full height of the building to the new roof top plant area.
The riser was so congested that to build it with traditional methods would have required much more floor space at each floor level. This space was simply not available.
The solution was to create a modular structural frame which would house all mechanical and electrical equipment within the heavily congested space and to build the entire fully equipped riser in Halsion’s offsite factory (in Kent) and deliver the riser in 3 main sections to the central London site.
Having previously been involved in hospital projects which adopted a similar approach including modular service risers up to 5 storeys high in Pinderfields Hospital, Yorkshire, Atom Consultants were asked for advice on how to build the riser modules.
The structure had to be strong enough to support the services both in the final installed positions as well as during transport to site. The riser also had to be built in 3 sections due to the sheer size of each module and to keep the installation weight of each section within the practical limits of the cranes available for installation.
Structural zones were limited due to the celling heights in the existing library and the inlet and extract ducting feeding from the riser at each floor level.
Every aspect of the design required detailed coordination to ensure that the final installed location of each connection from the modular riser sections was aligned to the service routes through the floor and ceiling zones within the existing building and the 2 newly refurbished floors.
The high degree of coordination involved could only be achieved using BIM. An area where Atom Consultants took the leading role.
The overall coordination model included: the existing building structure, ceilings, floors and walls; the structure, floors, ceilings and walls of the refurbished floors; the new rooftop plant area; the primary structure for the new riser, the temporary transportation and lifting strengthening elements and all the services designed by each specialist supplier.
In addition to BIM, Atom Consultants also took the lead in relation to the design of the riser structure. We determined where the structure would be split for transportation and how this would affect the services included within each section of the riser.
The typical size of a riser module when loaded on top of the delivery trailer was 5m wide with and overall load height of 4m and a module length of 8.5m.
These were huge modular units to be delivered from the leafy lanes in the Kent countryside right into the busy and narrow streets of central London and finally through the gatehouse and onto the Imperial College Campus.
The loading conditions during transportation and lifting operations were often more onerous than those in the completed structure and consideration had to be given to each key stage.
Construction tolerances between holes cut in the existing floors, framing around the openings in the new floors and for the module manufacture also had to be taken into consideration resulting in 3 very large modules being positioned within the building without any opportunity for rehearsal of the installation procedure. It had to be right first time and it had to fit.
Adding to the complication, there was a need to support the weight of the riser so that its full load was shared by supports at each floor level. This meant the structural ring frame providing the support had to be installed before the riser and making the installation dimensions even more critical.
Through the incredible efforts of everyone involved and the meticulous planning of each stage with BIM adopted at the core of the team for communication and resolution of all the issue, all 3 modules were successfully installed over a 3 day period.
What is even more incredible is that with the exception of the actual time when the modules were being installed by the crane, the Library in Imperial college remained open and accessible to the students.
This was an incredible feat of engineering at every stage of the project and one which is very fitting to have been carried out at the esteemed Imperial College with it’s eminent history and reputation in the field of engineering.
Atom Consultants are proud to have been an important member of the team along with Wilmott Dixon as the contractors, Halsion as the M&E specialists responsible for the service risers and the labyrinth of connected services and also the client’s representatives who provided assistance throughout the design, manufacture and installation phases.
See the video of the installation here
We undertook the design and construction of the Riser Project for one of our premier customers and Atom Consultants took the lead role in designing/coordinating and progressing the structural riser works. Atom also attended meetings with Halsion and our client and their design team to ensure that the riser design worked with the overall construction project and installation programme
Halsion have been involved in a few projects of this complexity, which due to technical and logistical constraints forces you to think outside of the box. This is the first project Halsion have worked alongside Atom, but found them very knowledgeable and considerate to the M&E services issues that needed to be overcome. Halsion also found Atom to be very approachable and flexible and could offer structural solutions which assisted in a multi-disciplined project coming together and provided a fit-for-purpose solution for the end user.
Richard Lester, Mechanical Contracts Manager, Halsion Ltd.