Castle House residential tower generates its own power through a series of wind turbines

Castle House residential tower generates its own power through a series of wind turbines. Collaboration between Bourne Engineering and steel consultant TDS Midlands was vital to the success and delivery of the project, and both companies were proud to integrate themselves to the team using Tekla Structures BIM software.

BIM collaboration creates green tower of wind power

Green towers are the new sustainable construction standard. Wind turbines are built on top of any tower over 20 stories to produce on-site energy. Castle House residential tower at Elephant and Castle in South London was designed by Hamiltons of London and targeted an ‘excellent’ rating under the British EcoHomes certification system. Built by developers Brookfield Construction of London, the project involved two buildings: a 43-storey building rising to 147 meters above ground level with three 9-meter diameter wind turbines at the top, and an adjacent 5-storey pavilion building. The Castle House provides 310 apartments along with retail units on the ground level.

Distinctive design

Bourne Engineering modeled the three wind turbine enclosures, which are a part of the scheme also known as Strata. The design is made distinctive by the turbines, and when combined with the sloping upper floors, they give the look of a certain shaving product, hence the nickname Electric Razor.

“This is actually far more complex than the initial impression with hundreds of unique brackets in the model to support the external cladding system. Once again it is a great example of the diversity of the models we now see created in Tekla Structures,” says Andrew Bellerby, managing director at Tekla UK.

The model of the 20-meter tall wind farm shows the enclosures that contain the turbines to form the housing around the plane of the blades, improving overall efficiency whilst avoiding wind noise or vibration. “The steel element of this project is the top section which contains the wind turbines within an elliptical frame design,” reports Andrew Newman, draughtsman at Bourne Engineering.

“The enclosures for the three turbines consist of 24 individual elliptical CHS sections and 6 curved CHS sections. Between these CHS components, beams connected to fin plates form a rib cage for the cladding. The steel structure was modeled in Tekla Structures to complement the shape of the top of the building and to form a complete frame to support the cladding in line with the main building. It has three circular openings. These are parallel to each other. With the building having curved and sloping faces this causes the face of the openings to be elliptical in differing planes to each other.”

Sustainable collaboration

“The design concept embodies a sustainable approach that minimizes energy requirements from the outset, whilst exploring opportunities to generate heat and electricity on site including three wind turbines and a combined heat and power plant. Bourne Engineering supplied the structural steel frame including the design, production and erection of the cladding support brackets. This project was trial erected on a temporary site at ground level to ensure accurate fit and to allow the frame to be reviewed by following trades to gain a clear understanding of the structure before being dismantled and erected at its roof top location,” explains Blair Thomas, drawing office technical manager at Bourne Engineering.

“The design and drawing model was developed by the Bourne team and fed back to the architects and engineers in 3D in order to coordinate the setting out of cladding elements,” Blair continues. “Points were positioned in 3D and checked against survey data coming from the fabrication shop to ensure that tolerance targets were achieved on the elliptical members. Collaboration between designers was vital to the success and delivery of the project and Bourne were proud to have the capacity to fully integrate themselves within the BIM working of the design team.”

“Models were often sent out as Tekla Web Viewer models to members of the design team and were also used in the development of temporary works solutions throughout the project,” Blair explains. “The ability to view complicated issues in 3D at a moment’s notice is an extremely useful tool. We use the Tekla multi-user mode for all projects. Multi user is of paramount importance on larger jobs and that is where it comes in to its own. For smaller more technical jobs, such as this, the multi-user functionality is often used to assist with drawing editing or checking of complicated elements.”

Steel design in the loop

Bourne Engineering supplied the Tekla model to TDS Midlands to use as a reference object. “For the Castle House project, we were employed by a specialist steel fabricator, OMC Engineering, to produce general arrangement and fabrication details for the cladding panels surrounding the turbines which make a prominent feature,” says Daniel Leech, commercial director at TDS.

“This provided numerous challenges due to the complex elliptical and curving plate work required to produce the final high specification finish. We supplied a 3D model of the cladding panels as well as general arrangement and fabrication details which enabled the accurate manufacture and installation of the structure.”

“We believe that this project could not have been completed with traditional 2D drafting methods due to the geometry of the turbines, and therefore without Tekla we would not have taken the job,” Leech points out. “We collaborated by exchanging information with the architect, engineer, and the steel contractor using the Tekla Web Viewer. Additionally, the ability to detail custom profiles was invaluable and used to great effect on the Castle House project, as well as most other jobs where we utilize Tekla.” TDS have been using Tekla Structures since 2008.

“As a company we were quite used to detailing projects of high complexity but we had noticed an increase in the number of jobs whereby a 3D capability would greatly improve the time required to detail these projects. Tekla was our first port of call. Within three months we got to a competent level in using the software.”

“We find Tekla’s ability to model complex projects in great detail invaluable for providing our customers with accurate manufacturing information. On the commercial side, the Tekla Web Viewer is an excellent tool for demonstrating the nature of our work to new and existing customers. Tekla Structures Model Reviewer is another excellent tool - one of the most advantageous tools Tekla has created. Tekla is perfectly suited to deal with the more technically challenging projects we often obtain. Its ability to import reference models of various formats, customize material and bolt catalogues, as well as create custom profiles combined with the extensive manufacturing output it can generate increases the scope of projects we can quote for,” Leech concludes.