Many hydropower and dams projects in development or under construction were stalled by Covid-19.

As the sector emerges from lockdown, delivery teams are tasked with remobilising sites and reprogramming projects, working round disruptions and shortages in the supply chain, and making up for lost time where possible. An added challenge in the ‘new normal’ is the requirement for social distancing between workers to minimise the risk of infection. Contractors need to find safe new ways of working that can be as productive as normal practices but avoid on-site trial-and-error which could result in further delays while impractical plans are rethought.

This comes as budgets are being tightened as organisations move to conserve cash, requiring a redoubled focus on improving efficiency and reducing risk for all ongoing and planned construction activities.

Solutions to these real-world problems can be found by working in a virtual one to optimise designs and rehearse construction activities.

Mott MacDonald developed Rehearsive by bringing BIM models into a live, collaborative environment

Taking virtual reality to a new level

Rehearsive, a digital rehearsal tool developed by Mott MacDonald, enables work sequences to be planned, tested, revised and perfected in virtual reality before being put into practice. It brings together personnel involved in planning and performing a task in a live, simulated site environment, which is created from the building information model (BIM) of the project.

The immersive technology allows users to not just see, but also interact with designs. They talk to each other as they virtually perform tasks and rehearse different aspects of constructing, maintaining, repurposing or risk assessing new infrastructure, collaboratively working out the most effective ways to get them done.

“You can plan and review operations ahead of time, with the freedom to fail and learn so that you can get the job done right, first time,” says Andrew Zhao, head of immersive technologies at Mott MacDonald. “Delivery teams will be able to plan temporary works more effectively and efficiently, reducing the time from plan to site. Rehearsing construction sequences and operational processes will flag up for correction any ergonomics issues, providing a feedback loop from design to build and to operation.

“The tool will also mitigate health and safety risks by helping users to identify potential hazards and snags, and to train staff in safe routes, behaviours and operational precautions,” Zhao adds.

Rehearsive comes with an extensive library of ‘objects’ – digital representations of structures, materials, components, plant and equipment – that allows for the rapid setting-up of different site arrangements, scenarios and conditions.

Different magnifications enable overview of macro-scale site logistics challenges, down to zoomed-in study of how to choreograph specific tasks. Those ‘on site’ can view the simulated environment using either a 3D headset or a standard PC or laptop.

Rehearsive is accessible using either a 3D headset or a standard PC or laptop


Cutting costs, cutting carbon

Mott MacDonald, which has over a century of industry experience since working on the first heightening of the Aswan Dam in Egypt, is recognised as a world-leading exponent of BIM to design and plan construction works.

The company believes Rehearsive, developed by bringing BIM models into a live, collaborative environment, will completely change the approach to experiencing immersive content. Digital rehearsal tools like this will become part of the new normal because of the valuable benefits they offer in terms of improved safety, faster delivery times, cost certainty, reduced carbon, and ultimately the bottom line.

Rehearsive has been trialled in other sectors and is now being offered by Mott MacDonald to its clients in the hydropower and dams industry, a sector to which the tool is well suited.

With site visits, for example, often involving travelling long distances to remote locations, Rehearsive’s voice chat and shared immersive environment allows infrastructure designers and operators to meet remotely and walk through construction scenarios with their teams and delivery partners.

This technology can also be used to communicate with stakeholders and deliver effective training and onboarding for site operatives no matter where they are located.

A fully equipped digital toolbox enables the identification of ergonomics issues associated with planned maintenance work

Return on investment

Used to assist with identifying and removing construction-related risks, Rehearsive can contribute to capital cost savings of up to 15% – the typical overspend arising from clashes, damage, rework and delay resulting from poor risk management.

Design costs are lower through more effective design reviews that can accelerate buy-in from clients and stakeholders as well as create more efficiently buildable designs, while construction costs are reduced by rehearsing and optimising construction activities before even getting to site.

Mitigating health and safety risks at an earlier stage will reduce risk costs. If maintenance is difficult or awkward, increasing the risk of reduced through-life value and increased waste, this can be mitigated by adjusting design and construction planning to take account of ergonomics both during construction and in maintenance and operation. 

Being able to rehearse different on-site activities at the design stage will realise the full potential of applying design for manufacture and assembly (DfMA) techniques, meeting the demand for off-site and near site fabrication, and supporting the emerging vision of a construction site as a place of assembly.

A further benefit is a reduction in the number of journeys to and from site, reducing carbon and wider environmental impacts.

“Rehearsive works in many ways to drive efficiency, reduce risk and improve quality,” says Richard Shennan, digital business development director at Mott MacDonald. “It is the first product that merges deep domain experience with leading digital expertise to deliver these benefits.

“As industry and economic activity recover from the pandemic, we believe it will prove its worth even more by boosting the productivity of those who have already recognised the efficiency benefits to be gained by using this technology.”

The tool comes with an extensive library of digital representations of structures, materials, components, plant and equipment

Spatial planning for social distancing

In response to Covid-19, Rehearsive has been updated to incorporate a social distancing visual aid.

“We have created a spatial ‘envelope’ around every user that displays a set boundary, allowing for site planning,” says Andrew. “This update will enable you to plan and rehearse your site operations in the context of physical distancing guidance.

“Many contractors are looking for this kind of solution right now. They will be able to save time and money by optimising the socially distanced construction process in virtual reality.”

Rehearsive forms part of the growing suite of augmented delivery and smart infrastructure tools supported on Mott MacDonald’s in-house technology platform, Moata.

“We cross-fertilised multiplayer computer gaming with BIM and visualisation technologies to develop Rehearsive,” says Andrew. “The graphics and strategic co-operation of multiplayer games like Fortnite have enormous potential for construction.

“Gaming has become a highly convincing multisensory experience. Once they’ve learned the interface, players have an incredible amount of dexterity and agility. And you’ve got this incredible social dimension with teams of up to 30 people working together in the same virtual environment.

“Virtual reality has come of age. And we’ve harnessed that to work through the practical challenges involved in construction.”

He adds: “Rehearsive is subscription-based – you purchase as many licences as needed for your number of users. Replacing just one in-person meeting a month pays for it. You can unlock value very quickly.”

For more information about Rehearsive, and to sign up for a free trial, visit

Users will be able to use human-centric data collection tools to explore and rehearse construction sequences