FEATURED PROJECT: Exhaust Stack – Carty Facility

In 2013, Portland General Electric commenced the ‘Carty Project’ in Boardman, OR. This project centered around the development of a 440-MW Natural Gas power plant. The Columbia River runs past town of Boardman and is near the Carty facility. Multiple barge loading/off-loading facilities exist in this area, which allowed for massive pieces of equipment to be shipped whole and direct to the jobsite.

One of the major suppliers of this project was NooterEriksen who specializes in Heat Recovery Steam Generator systems. As part of their scope of supply for the Carty project, TMF was contracted to manufacture the 23’ diameter x 230’ long Exhaust Stack. This structure was originally intended to ship whole by way of barge, taking full advantage of logistical benefits of our facility and our capability. However, to ease concerns regarding the installation of the massive stack as one piece, Thompson worked directly with NooterEriksen to make the stack truckable. Ultimately, the solution was manufacturing the stack in quarter-sections and in lengths between 40’-0” – 52’-0”.

The stack included heavy stiffener plates that ran vertically on the outside diameter and a beefy base flange when compared to the relatively thin shell plate. In that circumstance, warping/distortion can be common, so TMF applied heavy bracing to the structure to help mitigate and control any distortion concern. Before completion, TMF designed field-erection aids were also added to the stack-sections to assist with fit-up in the field.