Wessex Water uses digital technology to facilitate offsite construction
Wessex Water is advancing off-site manufacturing using digital technology.
The digital tools used during a water treatment plant upgrade provided a springboard for Wessex Water to explore the potential for new approaches to off-site construction.
Wessex Water’s Principal Digital Engineer Paul Verner says the real push for digital tools started with the water company’s £50million project to upgrade the Durleigh Water Treatment Center in the Somerset.
Work on the site near Bridgwater began in 2019 and has now reached the handover stage – but the effects of the approach taken there could be far more lasting than the three-year construction.
We realized that large equipment could be fabricated off-site, brought in and craned into place
The old water treatment center had reached the end of its life and major reconstruction was needed to maintain drinking water supplies for 44,500 people in the area. In total, 70% of the old water treatment center was demolished and recycled, obsolete equipment was decommissioned and removed and 30% of the structures were repurposed and/or renovated.
The digital delivery processes used from the start of the project included 3D Building Information Modeling (BIM), carried out by Wessex Water design consultant Aecom.
“One of the big results of the models was the realization that we could fabricate a lot of large structures and tanks offsite,” says Verner.
“Because of the precision involved in using 3D scans [of the site]we realized that large equipment could be fabricated offsite, brought in and craned into place. »
The idea is that you don’t have to create a custom design solution for every problem you encounter.
Items such as tanks and large sections of pipe were fabricated at Wessex Water’s off-site construction facility. Accurate installation was made easier as the team 3D scanned the existing area and used the data from the scans to ensure the new tanks and pipes would fit before they arrived on site.
The products were mainly made of stainless steel. A cluster of nine tanks, each around 12-15m high, was fabricated by a stainless steel specialist in his own factory and brought to the site for completion. This approach increased certainty as items could be manufactured in a controlled factory environment where there is heating, lighting and coverage from the elements not normally available on a construction site.
It also saved time, cost and materials, with the 3D model developed from the scans providing better accuracy of project information as well as greater certainty on associated costs, delivery schedule and risk management. In addition, off-site construction means that items can be manufactured in parallel with civil engineering and construction works, allowing direct savings on construction overheads such as plant hire and works costs. temporary.
“Overall, it was realized that these digital tools could be used effectively from several perspectives: health and safety, sustainability and speed of construction on site,” says Verner.
The Durleigh project was used as a testing ground for Wessex’s off-site construction strategy, encouraging the development of a standard product strategy for other projects.
Digital tools have enabled Wessex Water to further develop these standard products for its facilities.
The products are described in 3D models and in plans, sections and bills of materials.
These are then shared with teams and partners on the operations side through Autodesk’s BIM 360 platform so that everyone involved in the project can comment on and understand the product.
“So the idea is that you don’t have to create a bespoke design solution for every problem you encounter,” says Adam Bear, Wessex Water’s strategic digital manager.
“If you can have a standard or a collection of standard products that fit together, you can drop a design that speeds up the design and build process.”
This means less time needs to be spent on site and fewer materials are used, contributing to a reduced carbon footprint in the delivery process. Additionally, the products can be used in a variety of projects.
Bear adds, “If we’re constantly designing different solutions to the same problem, our operations colleagues have to spend a lot of time figuring out how to maintain those solutions. But if you have a standard design, the way it is maintained is also simplified. »
These standard products are then manufactured in the off-site facilities.
Since the beginning at Durleigh, this adoption of digital approaches has only accelerated.
“From then on, we evolved,” Verner says. “A fair number of smaller projects – under £1m – all moved almost immediately to BIM 360. It was the teams that moved forward on this digital tool.
“Over the past few years we have also introduced our own in-house design teams and we continue to design in-house, model in-house and use the approval systems we have in place in BIM 360 and ensure that governance is respected.”
Wessex Water now has standard document filing structures and approval processes for internal and external designers.
Some of the external designers can also upload their own designs and run their own reviews for Wessex Water.
This reduces emails and increases the accuracy of items going to the site. GPS coordinates are provided for each corner of each slab, so crews do not need to define dimensions with surveying equipment, saving time on site.
Additionally, it became possible to engage with construction and operations teams much earlier in the process.
“When we come to do design reviews, we can include operations so they can see what’s going to happen on their sites at a much earlier stage and even feed into the design,” says Verner.
“A lot of times that tends to lead to design changes. If we can make their life better and safer as an end user, that’s a great thing to do.
Overall, the use of a common data environment allows everyone to access it via a computer, tablet or phone.
“During confinement, even though we were physically further apart, we sometimes worked more closely together because we could share models,” he adds. “It’s a more collaborative and democratized way of working.”
Different tools for different projects
In addition to BIM 360, Wessex Water uses 2D tools, such as AutoCad Electrical. Different projects use different tools at different times depending on their needs. The use of 2D schematic tools makes it possible to link the graphical models of BIM 360 to a planning component.
“A model doesn’t have to be 3D geometry,” Bear says. “Previously we would have made drawings and then planned and made sure they tied together.
“Now you can design it once and it’s described both ways – you have the schematic layouts which are essential for understanding the big picture and the planning information which is essential for ordering, purchasing and determining the specifics of each individual valve and pump that you need to deal with.
As an owner, operator, designer and contractor, Wessex Water is uniquely placed to implement such solutions.
“We don’t just look at the design – we look at the entire asset lifecycle,” says Bear.
“BIM 360 helps us with this and enables the design, delivery and operation of the asset to be considered at the start.
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