Mining & processing

4.2 km Overland Conveyor Gantry & Transfer Towers

Name: EST Africa
Address: 17 Refinery Road, Driehoek, Germiston, Gauteng, 1401, ZA
Telephone: +27 11 383 1900
Price range: $$$$

Modular, pre-assembled conveyor trestles, gallery lattice bridges and transfer towers moving diamond ore across rough Kalahari terrain — designed for containerised assembly with zero on-site welding.

Industrial conveyor gantry crossing arid open terrain

Project data

Client: Orapa Diamond Operations
Location: Orapa Diamond Fields, Botswana
Year completed: 2023
Tonnage: 3 100 t
Length: 4.2 km of gallery and trestle
Steel grade: S355JR structural carbon steel
Coating: Hot-dip galvanized, 85 µm minimum
Modules: 312 pre-assembled bolt-together units
Site welding: Zero

The challenge

Skilled coded welders are scarce and expensive in the Kalahari, and mobilising a welding crew for 4.2 km of gallery would have dominated the project budget. Ambient dust also makes field welding quality difficult to guarantee.

Our solution

We re-engineered the conveyor gallery as a fully bolted system: 312 modules, each sized to a standard 12 m flat-rack, with HSFG bolted splices and direct tension indicators in place of every field weld. Modules were shop-assembled, galvanized and match-marked, then shipped in erection sequence so the site crew could build straight off the truck.

The outcome

Erected by a semi-skilled local crew with a torque-wrench methodology and no field welding whatsoever. The bolted approach cut site labour cost by an estimated 40 % against a welded equivalent.