PEW finds out how RMS partnered with LMOB electrical contractors to meet strict time deadlines for what they claim to be the largest offsite manufactured electrical and building services solution in Europe.
40 Leadenhall is a £885m 900,000ft2 office development with some retail and leisure facilities in the City of London. It consists of several stepped blocks that includes two towers, one of which is 34 storeys tall and the other 14 storeys high.
Large scale
The challenge for the electrical and building services was to find a solution that contractors could install incrementally one floor at a time while sticking to a strict timetable to keep the project on track.
Due to the scale of the project, the electrical contractor LMOB needed to install seven main risers, three in one tower and four in the other. They also needed a cable management solution to run the cabling to services on each floor.
LMOB contacted RMS with a proposed design for the main risers. These would be modular units that interconnect between each floor and need to accommodate a huge amount of services, equipment and cabling. Due to the complexity of constructing such units on site, RMS and LMOB decided that an offsite solution delivered to site incrementally to meet the build schedule was the best option.
RMS decided to prototype a riser module for testing and inspection to prove that the concept would work in practice before committing to manufacturing. Produced in just two days, the team made some minor alterations to this test module before it was signed off.
Said Pete Willshire, managing director of RMS: “It is one thing to have a design drawing for a solution but for large complex projects such as this it really pays to prove that the concept will work in practice. It is better to test a concept than having to alter it on a busy construction site.”
For the main installation RMS manufactured 460 modular riser units that the contractors installed one unit at a time. Many of these risers had services, such as electrical distribution boards installed within them. To achieve this, contractors from LMOB worked on site at the RMS factory in partnership with the company. This ensured that each prefabricated riser module with preinstalled services was quality checked before delivery.
RMS scheduled deliveries with LMOB so that the riser unit modules for each floor plus standard cable tray, trunking and other cable management products all arrived one week in advance as a complete package.
Each riser module connects to the module on the floor above and below it using a flexible link also designed and manufactured by RMS. These all had different heights since the concrete floors between levels have different thicknesses depending on how high each floor is in the building, with lower storeys having thicker floors.
Time saving solution
Said Richard Pendleton, operations director at LMOB: “We managed to cut the electrical installation time for each floor down from an expected 2-3 weeks to just three days. When you are working on large projects like this and need to co-ordinate different trades any time savings are a major factor in keeping projects on track.”
Working closely with LMOB, it was also a major logistical exercise for RMS to ensure that the right modules and standard products were all delivered to a central London site on schedule.
Continued Wilshire from RMS: “When people talk about offsite construction, they often think of complete rooms or pods that are connected together. Often however a manufactured solution removes complexity from the construction site to help save time and ensure a high-quality consistent build for a complex system.
“At RMS we are often involved in projects that combine bespoke design with offsite manufacturing at our factory with standardised cable management systems from our sister company Armorduct. It is far from a one size fits all solution. Modern projects demand flexibility to meet the challenges of a construction site and being able to flex to meet different needs is an important requirement from manufacturers.
“Over the years we have learnt that the best results happen when a specifier engages with us at the beginning of a process. In this case LMOB understood what they needed and we provided the design and manufacturing expertise to help them achieve this.”
40 Leadenhall is due for completion towards the end of this year. A major part of keeping the electrical and building services installation on track was due to offsite manufacturing removing complexity from the construction site to cut time on site. With the shortages of skilled labour available it is vital to maximise the resource that you have on site, so the role of offsite manufacturing is set to grow.
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