Since ancient times, builders have relied on drawings to provide them with the dimensions, scale and essential details needed to create stable structures. From clay tablets and papyrus sheets used thousands of years ago to oversized sheets of paper and blueprints used in modern times, drawings have been the central repository of information needed by many generations of builders.
Today, a number of technologies have the capabilities to make two-dimensional drawings obsolete. Programs like Tekla, Revit, Smart3D, Open Plant and others offer the potential to launch the engineering and construction industry into a new data-centric era that will save millions, reduce errors and increase the ability to stay on schedule.
Minute Details in Drawings
As structures have grown more complex, drawings have become incredibly detailed, with every aspect of plans, sections, elevations and connections depicted and matched to coding and extensive notes that provide fabricators and construction crews with all the information they need.
These requirements have translated into ever-more-complicated drawings. It’s no wonder that the construction industry is quickly moving toward greater reliance on computer-aided drawing and design (CADD) applications. Though drawings are still prevalent in the industry, we are increasingly driving fabricators, contractors and all other third parties to begin relying on 3D models for the data they need rather than hundreds of pages of paper drawings.
Advantages of Digital
It’s been obvious for many years that digital models providing the information needed for all phases of construction deliver a number of advantages. We recently took the leap to test these advantages by using no structural steel drawings on a $2.4 billion project — the largest in Burns & McDonnell history. The job requires 82,000 cubic yards of concrete, 13,000 tons of structural steel, 7,800 precast piles and hundreds of other components to be installed on a 1,600-acre footprint that will soon be home to a new industrial plant on the Gulf Coast.
Needless to say, there was some understandable skepticism from project engineers.
We already had support from both the project owner and construction partner, who had clearly indicated a preference that this project be managed in a data-centric format. The primary goal was to achieve better tracking and verification of quantities ordered and the precise status of each phase of work. However, we still had to demonstrate the advantages of this approach for every phase of project management.
Our proposal called for utilizing Tekla 3D modeling software, an application that the construction teams and fabricators are quite familiar with. The data from this application can be provided in formats that can be sorted according to requirements of the fabricators as well as developed into work packages for ease of constructability. Tekla has become a widely used application by the steel fabrication industry, featuring a robust application programming interface (API) that allows a user to do custom programming, including automation of many repetitive tasks and procedures using C# programming language.
We were able to demonstrate that this data-centric process using a robust 3D model as the core repository of all information would result in a time savings of at least 12% for engineering alone, simply by eliminating the need to check drawings against models to verify accuracy. Instead of the more than 10,000 conventional paper drawings that would normally be required for a project of this scale and scope, we were able to demonstrate it would only require production of approximately 250 isometric drawings — one for each steel structure.
After extensive reviews and multiple sessions successfully answering questions, the management team gave the go-ahead.
Efficiencies Equate to Cost Savings
Steel production is a critical path on this data-centric project. Deliveries must meet precise schedules and every component must be fabricated to precise specifications with tolerances of no greater than 1/16th of an inch.
Sharing volumes of data in standardized formats needed by constructors and fabricators keeps everyone on the same page. Orders for steel components are released directly to fabricators, who use the same Tekla model to relay those orders to mills. The program then interfaces with automated cutting, drilling and fabrication tools and equipment to provide the precise diameters, dimensions and other instructions needed for these tasks. This data is also fed into a database that allows construction managers to track quantities ordered and progress of production in real time.
This data-driven process is proving to reduce requests for information (RFIs) from fabricators, because all interferences have been checked before any of the steel is drilled, cut, shaped or welded. At an early stage in 2023, when 4,500 tons of steel had been ordered, there were fewer than 40 RFIs, a small fraction of what would normally be expected at that stage of a similar-sized job.
The exacting detail of the model results in very few clashes at connection points because of the ability to perform precise checking before fabrication tasks commence on any section of steel. Points at which sections of the steel may not connect with other sections are identified in the model and corrected. These types of structural interference checks are performed as a quality control step within the model, a task that is performed many times before work commences. Because every part of each pipe rack and all other related structures are already modeled, these interference checks can be performed more efficiently and with far less time invested.
Engineers, designers and fabricators are all checking the 3D model using standard connection codes within the Tekla model to provide excellent quality control. With every structure using the same types of connections and with those connections linking back to our standard details, communication with the fabricator is greatly improved.
Quality control for fabricators is performed by overlaying the model information that is sent back by the fabricators to verify that there are no discrepancies. This step replaces the laborious task of manually checking all fabricator shop drawings against the 3D model. By overlaying the fabricator data file onto the main Tekla 3D file, any discrepancies quickly become visible, saving many hours.
Stamping and Sealing
Authorities having jurisdiction over building codes have historically required paper-based drawings as the documentation protocol needed to verify that builders will erect stable structures that meet industry-accepted safety, occupancy and quality standards. These plan documents must be sealed with a stamp that conforms to specific standards established by state boards of engineers, architects and land surveyors. This step has been required for decades as the legally enforceable step that assures codes enforcement agencies that a registered professional engineer has reviewed and approved the construction plan and deems it up to code and safe.
Although these requirements stipulate that the plan document must be sealed with a stamp, they generally do not stipulate what type of document it should be. If the document is required to undergo local or federal plan review, the document generally must be a full-size drawing depicting plans, sections, elevations and details. However, in this particular jurisdiction, plan review was not an obstacle, which allowed us to create a single isometric drawing per structure from Tekla model data. None of the drawings included design information and even revision blocks simply instructed the reviewer to see the model for revisions in lieu of the typical descriptions of what was being revised. This met the requirement to submit a stamped document, with the model files containing all actual relevant data submitted as supplemental information.
Advantages Make Drawings Obsolete
With today’s technology advances, have we reached a point where the engineer’s stamp is no longer needed on paper forms of construction documentation? Can increasingly complex projects be managed better without the time-consuming task of checking drawings against a digital model?
We have set out to answer those questions and prove that digital models can actually provide even more accuracy and accountability than paper drawings on the largest project in Burns & McDonnell history.
By using the Tekla model exclusively as the project management tool for structural steel, many constructability issues have been resolved before any materials are sent to the shop. Both field and shop RFIs have been dramatically reduced because of the ability to do refined interference checking much further upstream in the process. Since all connections are modeled in detail, components like bolts, stiffener plates and dozens of other components are ready to be installed in the proper locations because any interferences have already been solved.
This is a data-centric project with massive amounts of data generated at each step. However, it is being sorted and ingested in formats that allow the owner to track progress via reports that provide up-to-date quantities and costs.
Though numbers are still being tallied, the cost savings resulting from fewer engineering hours were at $4 million and climbing by mid-2023. Cost and time savings are only a few of the advantages, however. Delivering a quality project that meets every aspect of owner expectations is the ultimate benefit — a goal that is being met with this move to data-driven project management.
Repeatable design and standardized processes are delivering benefits for many types of heavy industrial construction.
