Mammoet’s self-erecting pedestal crane performs efficient reactor head replacement, minimizing downtime and disruption.

A growing population means an increase in energy consumption. However, refineries often need to operate from their existing footprint. Because of this, sites can become congested as existing space is allocated for new process equipment.

Over time, this makes maintenance more complex. With a facility full of live and tightly packed critical equipment, safety becomes the key priority; closely followed by efficiency.

When a refinery undergoes maintenance activity, some operations at the site must halt whilst essential work is carried out. Therefore, any unnecessary downtime can add significant cost to a project.

As part of maintenance activity at ExxonMobil’s Fawley Refinery in the UK, Mammoet recently supported with the exchange of a reactor head in the FCC (Fluid Catalytic Cracker) unit.

Mammoet utilized its self-erecting FOCUS30 pedestal crane, which performed the operation with ease – replacing the old 356t reactor head in less time than other cranes while taking up a footprint slightly larger than a five-a-side football pitch.

Focusing on the challenge to perform heavy lifting in a constrained space

In 2006, Mammoet supported the exchange of a regenerator at the same site. The PT50 ring crane was used, which had a significantly higher load moment and smaller footprint than commercially available crawler cranes at the time.

Despite this, its boom had to be carefully assembled over live pipework as there wasn’t enough free space to construct it at ground level.

Eighteen years on, with even less site space to carry out this project, Mammoet’s engineers suggested using the FOCUS30. Dubbed ‘the crane that builds itself’, it has been specifically designed to perform heavy lifting in facilities with complex infrastructure and limited space.

This high-capacity pedestal crane has a boom that is erected vertically in sections, instead of horizontally. Each boom section is inserted like a jacking cartridge before being lifted to make room for the next underneath.

This not only allows for faster assembly, but for the crane to be built in a footprint measuring just 34 by 42 meters. It also means that the crane’s boom does not need to be laid flat before erection, potentially blocking access roads on site.

At the planning stage, Mammoet’s engineers conducted a full 3D scan of the refinery’s reactor and, using in-house planning software Move3D, created a visualization of the project to show how the pedestal crane would be positioned and utilized on site.

By utilizing this software in combination with 3D scan data, it was possible to identify any clashes in the highly congested site. The lift’s close proximity to an absorption column demanded a level of scrutiny and accuracy that couldn’t be provided by a traditional 2D approach.

By carefully positioning the FOCUS30 crane around existing infrastructure, hardly any alterations were needed in the field. Only one large pipe was identified early in the engineering process, and this was able to be removed without delay.

Mammoet designed a specialist lifting beam that could be inserted through the top nozzle of the reactor head and clamped to its interior. The lifting beam had two large lifting pads that carried the reactor top from the inside of its plenum. This methodology provided a sure grip of the reactor head as it was lifted.

The FOCUS30 was configured with a divisible superlift tray of 900t and 400t sections, which made movement of the ballast fast and simple, while making sure that the crane did not need to slew over live pipe racks with the load.

The FOCUS30 is also much less susceptible to high winds than alternative crawler cranes, which would typically have to boom down at around 16 m/s wind speeds, causing significant disruption on site. By storm anchoring itself to its own outriggers, the FOCUS30 can withstand conditions more than twice as harsh, giving owners peace of mind projects will not suffer significant wind delays.

Pedestal crane built for faster, safer refinery operations

The FOCUS30 demonstrates Mammoet’s commitment to supporting its clients in overcoming heavy-lift challenges through innovation and considered design. It is helping to make refinery maintenance significantly easier, faster and safer – even as sites grow more complex.

Its use alongside Move3D allows maintenance projects at sites that have existed for many decades, changing year-by-year, to proceed with confidence that every millimeter has been accounted for.

The FOCUS30 has 30,000 tonne-meters of load moment, yet has only one-sixth of the footprint, compared to currently commercially available crawler cranes with comparable strength.

It solves three of the biggest challenges that plant owners face: lifting capacity, space, and time - as Koen Totté, Sales Manager at Mammoet, explains:

“It takes around three to four weeks to assemble the FOCUS30. By comparison, a heavy lift crawler crane would have taken around five weeks.

We would also have needed to build its boom over the pipe rack, which would have been very time consuming and added risk due to working at a height of around ten meters over this live plant.

With the FOCUS30 we could work from inside the crane’s footprint, and not have to work at great height, making it a much quicker and safer alternative”.

For more information, please visit Mammoet's website.

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