Deep South has completed a major refinery upgrade project, replacing two coke drums within a tight timeframe. The project presented significant logistical challenges due to the size and weight of the coke drums, which each weighed 452,800 pounds (approx. 205 tons) and measured 19 feet 2 inches (4.85 metres) in diameter and 96 feet (29.3 metres) in length.

The upgrade was carried out as planned during a scheduled outage. The coke drums were received by Deep South from a ship at the Port of Houston and then transported by barge to a dock on the Calcasieu River in Louisiana. Upon arrival, the coke drums were unloaded from the barge and positioned using the 440-ton Terex-Demag CC-2400-1 and a 500-ton Liebherr LTM1400-7.1 tail crane. Each drum was then erected into a vertical position and placed in a jig stand for insulation to be added.

To replace the coke drums and remove the derrick structure, Deep South used its VersaCrane TC-24000 in Configuration VI. This crane’s design allowed for minimal ground preparation reduced the need for rock in the pit and provided better tail swing clearance, resulting in fewer site impacts during the turnaround activities.

The final challenge was to manage the allowable ground-bearing pressure on the sluiceway pit wall. The VersaCrane TC-24000, with its low ground bearing pressures, eliminated the need for wall shoring, saving significant time in site preparation before performing lifts.

Moving the crane in and out of job site

In order to keep the refinery unit operating at full capacity until shutdown, the crane had to be assembled offsite and then moved into position when ready. This move was a first for Deep South. It required close cooperation between the project engineering and VersaCrane design engineering teams. Detailed calculations, taking into account the weights of every crane component, were necessary to determine the crane’s composite center of gravity and ensure its stability during transport. The transporters were sized to meet low ground bearing pressure site requirements, guarantee crane stability during the move, and allow them to maneuver tight clearances on a congested site.

The result was a custom transport plan that exactly met the client’s needs. The crane’s transport from its assembly/staging position to its final lift position took approximately one hour. Overall, the off-site assembly saved approximately 15 days when considering mobilization, assembly, disassembly, and demobilization.

Once completed, Deep South moved the assembled crane into the final lifting position.

The drums were taken out and placed onto a 12-axle-line Goldhofer E-Series for in-plant transport of existing/old coke drums. They were then transported to the laydown area and offloaded using a 700-ton gantry jack system for later disposal. Once the new coke drums were in place, the derrick structure was reset.

To avoid delaying unit start-up, Deep South transported the fully-assembled VersaCrane TC-24000 back to a nearby laydown area for disassembly and demobilization after completing the coke drum exchange.