Enhancing Carbon Bake Furnace Safety


Providing bespoke Pit Maintenance Units (PMU) for the Mozal Aluminium Smelter in Mozambique.

Our pit maintenance units (PMU) create a safer and more efficient method for aluminium smelter staff to access their carbon bake furnaces. The Mozal Aluminium Smelter in Mozambique has experienced this first hand.

Farra first created pit maintenance units for the Mozal smelter in 2002. In 2017, after 15 years of service, the well-used units were set to be retired.

Replacement PMUs were needed and who else would Mozal go to but Farra.

The two new PMUs were custom designed to match the layout and dimensions of the Mozal smelter and incorporated the newest innovations for PMUs.

These innovations included trackless relocation, dual gantry cages, and pit brushing units.


Key Facts

Commissioning on Site: With the extensive testing Farra completes in the workshop, each PMU can be commissioned on site within three days.

Running Times: Our PMUs are designed to run 24 hours a day, seven days a week.

Unit Weight: Each unit weighs 12.8 tonnes.

Installed: The PMUs were installed on site in November 2018.

Trackless Relocation

Trackless relocation of the PMUs enabled the units to be driven with a remote between the Mozal Smelter's carbon pits, saving time and freeing up their FTA crane for other essential smelter operations.


Dual Gantry Cages

To double productivity, the Mozal PMUs were designed to have dual gantry cages. Each gantry cage had a safe working load of 350kg and were suspended by four corner wire ropes, connected to a single layer hoist and was fitted with two independent brakes to ensure the safety of the user.

The two cages allows the Mozal staff to work on multiple pits at the same time.


Pit Brushing Unit

Farra's innovative pit brushing unit is attached to the base of the gantry cages and helps to avoid the build up of carbon pieces. As the cages descend into the smelter pits the brushes extend to remove excess carbon that is still attached to the pit walls after the baking process is complete.

Having the brushing units in place eliminates the need for Mozal staff to manually scrape the pit walls.


The proven solution for access to carbon bake house furnaces are our pit maintenance units and with our added innovative design features the Mozal Aluminium Smelter will continue to work safer and more efficiently.