Lee McDougall, Director at architecture and building consultancy practice AHR, outlines why scan-to-BIM technology is key to delivering state-of-the-art station refurbishment and long-term facilities management
Rail stations across the UK provide essential infrastructure, so ensuring they remain in optimum condition is essential. Given this fact, it is surprising that the uptake of technology to streamline station refurbishment and management has not yet become the industry norm. Scan-to-BIM harnesses laser scanners to create a 3D point cloud model and visualisations of an existing structure. The point cloud model comprises millions of spatially correct points and can then be used as the basis for a fully developed BIM model.
The use of scan-to-BIM is an innovation that has the potential to transform the way station refurbishment is executed, as well as longer term station maintenance and management. With multiple levels of detail available, its use can create data-rich models of all buildings and facilities. These models provide a single point of reference for information on any given asset, ensuring all those working on a project have access to the most current data at the same time.
From the creation of a mass model showing external outlines, to technical design and as-built models, BIM can provide a range of information vital to station refurbishment and maintenance work. As such, its use is increasingly being stipulated in project briefs.
Realising the potential of BIM
Scan-to-BIM provides a multitude of benefits when applied to station refurbishment and development projects. Enhancing health and safety, lowering costs and reducing project time are goals that are often seen as mutually exclusive. This is not the case when scan-to-BIM is implemented.
Taking health and safety as an example, we can see how using scan-to-BIM at the survey stage delivers improvements – without risking increased cost or delays. When working on busy rail stations, health and safety is paramount. Winter weather can create hazardous station platforms, an issue compounded by overhead electrical cables and passing trains. Creating a safe environment in a rail station is not an easy task in normal circumstances and survey and refurbishment work complicate matters further, with pedestrian areas requiring restriction while work is undertaken.
One of the key advantages of scan-to-BIM in surveying is that the laser scanners used in this process capture data at great distances remotely. This means the existing station can be scanned, with all the geospatial information captured, without having to be close to hazardous areas like platform edges. This helps to protect the health and safety of both the project team and passengers.
The ability to undertake this work at night also helps improve passenger safety and reduce disruption. Instances of overcrowding, which could be caused by the reduction in space available to passengers while work is undertaken, are mitigated. In addition, scan-to-BIM enables an exceptional level of detail to be captured in a fraction of the time usually associated with collating survey data.
These scan-to-BIM benefits are well illustrated by the work AHR undertook at London Euston Station, where this technology was used to create a 3D Revit model of the station concourse and platform ramps. Laser scanners were used in four overnight four-hour slots. This saw over two billion coordinated 3D points observed and captured to create a point cloud, which was subsequently turned into a 3D model, providing designers with the key information they needed for the refurbishment work. This included how the concourse and station platforms, which are set at different levels, interacted with each other. There was no disruption to passengers, as the laser scanning was carried out overnight, and work was completed in half the time associated with traditional surveying techniques.
Likewise, our scan-to-BIM work at Leeds Railway Station provided vital information in the form of a highly accurate BIM model, ensuring the success of their south entrance extension. The model provided information on the surface curvature of the building’s geometrically intricate structure to enable an efficient, informed design process.
In addition, the detail provided on the complex confined site, with a rail network and fast flowing river in close proximity, allowed the team to plan aspects of delivery and general site health and safety. The BIM model was handed over to the client to be utilised for asset management, with the capacity to integrate future development plans for the station, such as the arrival of HS2.
Many of the rail stations with the most pressing need for refurbishment are heritage buildings. In some cases, they may be listed buildings, a factor that can complicate surveying and refurbishment work.
In this situation too, scan-to-BIM can offer a solution. Through the use of remote laser scanning to build a detailed 3D model, there is no need for any direct contact with historic sections of a train station. This means that the possibility that these sections could be damaged during the surveying work is completely removed – a significant risk when working on listed buildings.
AHR’s geomatic consultancy team was appointed to scan and model a large part of Edinburgh Waverley Station, including the Grade A Listed ticket hall. The use of laser scanning on this project allowed the creation of a point cloud without any contact being made with the existing fabric of the station.
This ensured the structure remained completely undamaged. As with the London Euston example, work was completed within a fraction of the time usually associated with survey work. Key data including coordinated 3D points, dimensions and area values were attached to the digital model.
This information was stored in a digital portal, with the model acting as the single, authoritative source of information for all parties involved in the subsequent refurbishment project. This provided absolute clarity, minimised risk, and enabled the delivery of a high-quality project.
Using BIM in FM
It is clear that scan-to-BIM technology can have significant impact at the surveying stage of a refurbishment project. However, its benefits don’t stop there. The huge amount of data captured using scan-to-BIM creates a comprehensive point of reference for facilities managers.
BIM data can form the basis of a sophisticated facilities management system, which delivers value throughout an asset’s lifecycle. In fact, the value that such a model brings can increase over time – as more information can continually be added into the system.
Typically, station models are built piece-by-piece. It is unlikely that a whole station will be scanned as part of a single refurbishment project. However, as further projects are undertaken, the model can be gradually extended.
This means a vital source of information for facilities managers can be built up over time, without the need to incur prohibitive upfront costs, and can be updated easily. The result is a long-term asset management tool that goes far beyond the initial survey work, with the capacity for increasing detail to be added over time.
For these reasons, the use of scan-to-BIM in rail refurbishment projects should be a key consideration across the industry.
As time progresses, digital models of material assets in the rail industry will become the norm, aiding maintenance and long-term management. Forward-thinkers shouldn’t wait to capitalise on the benefits this technology can bring to their projects.
Lee McDougall is Director at architecture and building consultancy practice AHR