In his recent blog, my colleague Tim Kelly wrote about modular design and how 3D Design is a perfect fit for being able to reduce cost and increase scaling on projects like hospital rooms, dormitories, and so forth.
One of the problems that constantly creeps up with using a modular design is that you have to make sure things are going to fit perfectly when they arrive on a job site.
It’s a three-tiered process that has a lot of different solutions that require adaptive, creative thinking to avoid a catastrophe when the modules arrive on-site, but for the most part each of these revolve around the concept of collaboration and information sharing.
3D Design: Too Perfect?
In some ways, the BIM tools are too perfect, because they ensure the design is exact – down to a thousandth of an inch. But you can’t construct things that perfectly, really you can’t build within an eighth of an inch half the time. So that begs the question, how do you control that discrepancy?
The main answer is that you have to have a plan, and then follow the plan thoroughly before the modules are shipped to the site. Once they are there, the price of delays for rework and readjustments isn’t just in the cost of construction, but in the value lost. If the factory or plant you’re building or adding on to has to be shut down for 4-5 days because of design flaws, that’s the real value lost. We’re talking about days of revenue lost for companies, and ripples down their supply and delivery chains that send revenue losses spiraling out of control.
A solution for every problem or at least we are told!
Every project has a design specification to ensure things are going to stack up properly. The art of tolerance stack management is key to understanding how your project will eventually fit up. You can do collaborative construction and engineering, you can do mechanical estimations, use surveying and metrology equipment like 1 second total stations or laser trackers, and more.
A great example of thinking outside the box on modular builds comes from a project I worked on where the pieces being shipped were the size of a small building – about 3-4 stories tall, 100 feet long and 500 feet wide. We were fabricating these PAMs (Pre-Assembled Modules) in Thailand and floating them to Australia for installation. The client built these special robots that were about a meter off the ground but could lift tons.
The robots drove the pieces to the dock and verified each connection point between each interconnecting components, including bolt holes locations, this information was then sent to the site in the AU, which allowed for the correct spacing of the bolts prior to the concrete pads being poured. We also verified mating component between the modules prior to them being loaded on the ship. Then we did the math about how things were matching up and what the job site looked like, and had a team on-board the vessel to fix the flaws on the trip to their final destinations. When you see efforts like that, you realize it’s not always about comparing the design to the field conditions at the site.
More recently we did a project for a major EPC in which we took the bolt count and created a list they could load into the total counter. At the site, the bolts were set before they poured the concrete so they would match the modules that were built. We gave them the exact location of where the bolts were located so they could match what was built, not necessarily what was designed.
This also gives us the ability to have a client walk in and ask questions, and use our database to show them all the information on how everything works and how it was constructed. This is what I like to call a complete traceability path, capturing each step, for who, what, when and where a task was performed.
The bottom line is that no matter how perfectly planned a modular plan is, it’s going to hit snags along the way. 3D Design and the use of BIM software should be thought of as a tool, that should create flawless designs, but the application of said designs will come with bumps in the road that will take human innovation to correct.
This blog post is by Mark Klusza. Mark Klusza is the Vice President of Research & Development at Assemble Systems. With a career expanding over 30 years in the construction industry, Mark has started and successfully grown multiple software companies in the construction space specializing in 3D imaging, laser scanning and data management. Mark is a two-time ENR Top 25 Newsmakers for technological innovations. At Assemble, Mark is focused on driving continued innovation in the solution offering and expanding the company’s footprint to a wider audience in the AEC industry
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