Modularization In Heavy Industrial Applications

Recognizing Scott Dumville’s extensive expertise in engineering and modularization at The JNE Group of Companies, this exclusive feature provides insights into the evolving role of modularization in heavy industrial projects. It explores key applications, challenges and best practices, offering valuable strategies for optimizing construction planning, improving efficiency and addressing site constraints in large-scale industrial settings.

Modularization in Industrial Construction

Modularization has always been an important topic in the construction planning for heavy industrial projects, particularly when it comes to capital projects at integrated steel mills. Over the past 25+ years, the application and benefits have evolved substantially. Historically, modularization has been used to reduce costs, improve schedules and alleviate site congestion by allowing some of the work to be performed off site at potentially lower rates. A prime example is the use of panel-built steel fabrications, which allow the installation of large panels rather than on site stick build structures.

Modern fabrication techniques and improved shop quality control have expanded the scope of modularization. Whether or not modularization can be used will depend on having access to skilled contractors and fabrication shops with rigorous quality control programs. The following sections explore various applications, to further highlight both its benefits and challenges.

Equipment Support Structures

A notable application of modularization is the large lift installation of equipment support structures. The Cleveland Cliffs DRI structure in Toledo, OH, is a great example of this approach. The 457-foot furnace reactor tower was erected in 11 separate lifts using one of North America’s largest construction cranes with a 3,000-ton lifting capacity.

The advantages included enhanced safety, reduced schedule and increased productivity. By limiting structural erection at high elevations, worker safety was significantly improved. Additionally, assembling modules at ground level instead of stick building at elevated heights accelerated the schedule by months due to improved worker access, increased sub assembly and reduced wind-related delays. By having access to several modules at once on grade, trades could plan their work on separate modules without having interference from work occurring overhead. However, potential disadvantages involve risks of misalignment and additional costs due to the need for larger cranes and interim structural stability that is not required for stick-built conditions. An alternative method to consider is top-down construction rather than bottom up. This complex process involves added framing to raise and pin the structure, allowing the next section to slide in from below. While it is safer, as work is done at ground level, it requires extra steel and project controls.

Utility Racking

Another instance of modularization in practice recently involved utility racking at a brownfield project. In this particular case the racking included numerous large and small bore pipes as well as a number of cable trays.The engineering design called for the erection of towers and bents with installation of utilities in long span fabricated box trusses above the support steel. Each box truss module required short utility infill sections at module connection points.

Due to a change in execution planning, the large bore pipes were installed underground in a deep trench instead. This required adding cathodic protection to prevent corrosion and led to a schedule extension due to construction challenges, including groundwater issues and unexpected underground obstacles. The revised plan helped avoid potential misalignment of services and structural elements.

The prefabrication of rooms and pulpits is a common application of modularization. These installations often involve extensive electrical and mechanical installation due to the room requirements and use. This modularization approach to these types of rooms and pulpits allows more work to be completed in a controlled shop environment rather than on site. This ultimately minimizes on-site rework and schedule risks, even when shipping splits are necessary due to size constraints.

Best Practices for Modularization

For effective modularization, identify potential areas early in the project, such as during FEL2 or basic engineering. Once identified, the next step is to analyze the situation according to the metrics that influence decisions on your project. Common tools used for this would be a cost and schedule benefit analysis as well as a risk analysis. Engaging a local fabricator/general contractor and a specialist lifting equipment supplier may be beneficial at this stage. The use of modularization can sometimes require larger cranes and the availability of such cranes could impact the schedule or the size of planned modules.

It may be necessary to reserve main lifting equipment well in advance. Engaging a fabricator early in the process can help define the fabrication strategy, such as shop fabrication of sub-modules to be site-assembled into main modules.

A study will be necessary to assess access from the fabricator to the shipping route, considering the limitations on transportation by road, rail, or ship, as well as the transition from receipt at the plant to the erection or module build site. Due to the potential size and weight of these main modules, an evaluation of existing underground or above-ground structures will be required to ensure adequate clearance and load-bearing capacity. Even with stringent quality control processes, employing secondary verification tools such as 3D scanning could mitigate alignment risks during high-altitude assembly.

Modularization can be a powerful tool in heavy industrial projects when properly planned and executed. This article aims to provide insights and methodologies to evaluate and integrate modularization effectively in your projects.