Matt Walker, Senior Engineer, at global design and engineering consultancy Atkins, explores how design innovation in the use of building information modelling - BIM - for the Ipswich Flood Barrier delivered significant benefits, including costs and time savings, with the potential for development into an asset information model in the future.

Matt Walker: BIM is a word we hear often when we talk about projects today. What we don’t hear as much are examples of BIM that have been implemented and delivered, with a successful asset up and running.

The use of BIM in design delivery of the Ipswich Barrier is a great example of BIM in practice, and one we should share with the industry more widely.

The barrier is part of the Ipswich flood defence management scheme, an important piece of infrastructure in an area prone to flooding. The barrier is designed to protect Ipswich for the next 100 years, defending over 1,600 homes and 400 businesses from tidal flooding from the North Sea.

As one of the Environment Agency’s larger scale projects, it was selected as an early adopter BIM pilot scheme back in 2014. The Environment Agency are now mandated by Government to use BIM on their projects and, as a forerunner to this mandate, wanted to trial the use of BIM on the project to see how it affected works and added value, with the ultimate aim of developing their own BIM requirements.

As part of the VBA joint venture, we helped the EA develop their BIM Employers Information Requirements and information management approach, formally responding with a BIM Execution Plan. We used 3D design throughout the project, including creation of a federated model for the main barrier structure that brought together several different models from different disciplines, including our Heavy Civils team and German gate designers.

This helped us to check for clashes and unforeseen impacts across the various designs. If any clashes were identified, we managed the clash resolution process with the designers to ultimately create a clash free model. This meant issues were addressed before construction and the barrier could be built seamlessly with minimal issues on site.

Main benefits of using BIM and 3D design for project design included time and cost savings

One of the main benefits of using BIM and 3D design for the design of this project was through delays avoided, which is hard to quantify. That said, by detecting and resolving clashes in the model, and sequencing the installation of some of the more complex elements of construction, we estimate that several weeks of time on site were saved, with the associated cost savings of running a site of this size.

A great example of this is the installation of the main barrier gate. At over 20m wide by 9m high and a weight of 200 tons, it is a huge structure. But despite its bulk, it was lifted into position right first time with no problems and lowered into its recess and sealed without any issue.

While the 3D model did take time to build, it was used a lot over the course of the project, not just during design development but on site with the contractor, for buildability, spatial coordination with the client’s operation staff, and to produce as-builts. It was also used for visualisation with Ipswich Borough Council when amendments were needed to the accepted planning design – the 3D model made it easier to gain approvals.

Design innovation saves £000s in maintenance

Although the project is now complete, there is a maintenance legacy our work has left. We created an innovative approach to changing the orientation of the hydraulic cylinders that operate the main gate, thus enabling the gate to be fully raised to its maintenance position using just the cylinders. This avoids the need to bring a crane to site to raise it to the maintenance position – a contract lift which could cost upwards of a hundred thousand pounds.

We’ve also put the foundations in place for the 3D model to be developed into an asset information model. If this information is available in a digital format, people on site could bring the barrier up on an iPad or Virtual Reality headset and scroll through and click on various parts for maintenance advice. There is great potential here.

While the BIM procedures and methods I’ve spoken about don’t seem particularly new or innovative, they were five years ago. More importantly, we’ve left a lasting legacy at the EA – 3D design and BIM is now mandatory on all projects, from the smallest to largest schemes.

I sit on the EA BIM working group, a collaborative team that ensures the learnings from the Ipswich project are carried on to the next EA framework and all projects do the ‘BIM basics’. The EA now look at BIM from the outset of projects, defining it in the early stages and allowing the time for models to be created and information maintained. There is a great understanding of not only the upfront cost of BIM, but the value it can add.

Ipswich barrier is a great example of BIM, delivered.