As ethanol plants become larger and more complex, their construction also increases in complexity. With a variety of welded, stainless steel tanks required for storage, fermentation and processing, tank construction is quickly becoming part of the construction critical path schedule. As a result, the best tank subcontractors are industrial construction companies with in-house expertise that take responsibility for the scheduling, safety, quality and construction of the tank structures from design to finish.
The tank subcontractor is typically the largest subcontractor on an ethanol plant construction site. Therefore, experience is critical. They must understand the nuances of an ethanol plant and its related construction sequence. They must also be able to integrate their schedule—and stay on it—while coordinating with the other trade personnel and subcontractors building the project.
Leading tank construction companies begin working on design by examining the request for proposal requirements and providing recommendations to the plant manager on constructability, design and schedule in order to make the project cost effective and easy to build. They must understand safety aspects and tank fabrication, and have the ability to work with other subcontractors. Tank construction companies should be able to offer suggestions to the project design team on how to best put the construction plan together.
The safety aspects of tank erection on an ethanol plant site are another important consideration. Tank design must follow designated codes and owner specifications, and be built safely and on schedule by crews experienced with welding, erection systems, scaffolding and other specialized equipment.
The tank subcontractor's shop processes must be designed to enable tanks to be erected efficiently and cost effectively in the field. Creating larger subassemblies in the shop cuts down on the time it takes field crews to erect the tanks, saving time in the master schedule and money in the budget.
Many experienced tank subcontractors are safety experts and operate efficiently. However, what sets the best subcontractors apart is the processes they have in place for building a tank from design to finish, and the controls they have over those processes to ensure they are carried out in the most effective manner.
There are typically three distinct phases of tank construction—project preparation, on-site construction and project finish—and a number of steps contained within each phase. As each tank company conducts business differently, the details of the construction steps are going to vary from contractor to contractor. However, most plans should include a few basic requirements.
Project or Job Preparation
Construction activities that should take place at the tank subcontractor's headquarters and/or shop facilities include:
› Forming the project team Ideally, all members of the construction team including the project manager, construction manager, engineers, drafters, shop fabricators and procurement personnel are in-house employees. They should be selected for their experience and should serve on the team for the duration of the project.
› Design engineering The engineering and drafting teams should use the latest drafting/computer-aided design programs to create drawings for the project consistent with national standards and in compliance with the project's local codes.
› Materials acquisition The in-house procurement team should purchase the raw materials required for the project and arrange for their shipment to the shop facility. Procurement may happen simultaneously with drafting because of the shop fabrication lead time needed to meet the tight construction schedules of most ethanol plants.
› Shop fabrication The fabricators should then process the raw materials in accordance with the project requirements. They should fabricate and roll stainless steel plates for tank walls and cut floor and roof plates, structural members and accessories such as nozzles, manways, ladders, baffles and platforms.
› Mobilization to the job site When the fabricated pieces are ready to be shipped to the job site, the field crews should be ready to mobilize. They should be on-site before or as the pieces arrive to establish and set up the trailer, power requirements and material lay-down areas. The subcontractor should pay special attention to shipping sequences so the first parts off the first truck are the first ones needed.
Safe On-site Construction
Once on site, the tank erection team should be managed by their own construction supervisor who works closely with the plant project manager to ensure effective communication. Processes during this phase may include:
› A pre-construction integration conference The tank team's supervisor should meet with the plant builder to share expectations and establish two-way communication.
› Prioritizing multiple tank installations The tank team should develop construction phases based on the site-unique priorities and challenges within the overall project.
› A pre-construction safety evaluation The site should be evaluated to identify potential hazards for the crew and the construction process, and eliminate any resulting issues.
› Site preparation, including foundations, as needed The tank team should evaluate existing foundations, identify any problems, communicate them to the plant project manager and work with the plant builder to develop solutions.
› Daily job hazard analysis Daily meetings should be held with the on-site tank team to review and discuss hazards that are specific to the day's work to ensure all workers stay safe.
› Regular quality and safety checks The tank subcontractor should have processes in place for personnel from inside and outside their company to test the quality of the work being completed. These checks may include x-ray tests of welds, unannounced safety checks and inspection record-keeping to identify any problem personnel or areas.
› Schedule updating The tank team should routinely update project schedules, integrating the needs of the project, other subcontractors and the builder, as necessary. Situations can change, so the tank subcontractor needs to be able to adapt.
› Weekly coordination meetings The on-site foremen should call headquarters for a meeting with the rest of the project team to ensure all departments are aware of the project's status and can resolve any problems.
Project Finish
The project isn't complete for the tank subcontractor until the builder and plant manager are satisfied with the end result. Processes completed as part of the project finish include:
› Clean up The tank team should remove all evidence of their crew by returning the job site to its original condition or better.
› Punch list assessment and completion The tank team's supervisor should walk the site with the project builders, another project manager or a construction manager who can help identify punch list items from a fresh perspective. If the builder develops the punch list items independently, the team should evaluate the list, adding to it if necessary and communicating any issues to the builder. The punch list items should then be resolved.
› Departure Once the punch list items have been resolved, the tank team should depart, but the tank subcontractor should be prepared to send team members back to the site to resolve any additional punch list items or warranty issues.
Experience, efficiency and adherence to safety are important factors to consider when reviewing a tank construction company's qualifications. Carefully reviewing proposals, requesting references and asking about any of the information presented here will assist in the selection process and help ensure successful tank and project construction.
President Jim Clay and Project Manager Scott Roark are with Advance Tank & Construction Co., a leading designer and fabricator of municipal and industrial tanks. Reach Roark at sroark@advancetank.com. Both can be reached at (970) 568-3444.
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