Pre-Planning and Precision: How We Moved Several Giant Chemical Tanks

By Project Engineer Brent Howarth

The Marcy Gulch Wastewater Treatment Plant south of Denver project recently hit a huge milestone — installing. six sodium hydroxide tanks, some weighing nearly 9,000 pounds, into their permanent home. These tanks are essential to the proper functioning of the water facility. 

This massive operation took a lot of strategy, and more than a little patience. 

Working with our General Superintendent Darrel Gonzales, we created the initial plan. Then others and I on the project worked alongside Flatiron’s Construction Engineering Group to make that plan sound and safe. The main focus was getting the roof to support the tanks. The roof beams needed to hoist the tanks had a maximum load of 4,500 pounds, so we used two trolleys that allowed the load to be pulled vertically off the beams. 

Several pieces worked in tandem to position the tanks. 

Operating safely under the load maximums, we moved the tanks horizontally through the door with a beam trolley/chain fall combination in front of the tank and used a forklift to lift the bottom of the tank. The hoists in the front and forklift in the rear worked in tandem to get the tanks through the door. 

 Watch a short video of how we hoisted in the tanks 

Once inside, we lowered the crane rigging through the existing roof hatches to attach the rigging to lifting lugs at the top of the tank. We then moved the chain falls to the bottom of the tank in order to tip the tank. As the main hoist line was lifted vertically, we simultaneously lowered the bottom of the tank with chain falls to get the tank in a vertical position. We then set the tanks on Hillman rollers (“skates” to help roll the tanks) and moved the tanks on a pre-built platform leveled with the tank pads. On the tank pads, we orientated the tank in the correct position and lowered it with jacks.  

Now that the tanks are in place, we can move forward with HVAC and other utility work in the chemical building. 

While I was heavily involved in putting the chemical tank–set plan together, it really was a team effort. I’m fortunate to work alongside diligent co-workers here at Flatiron.