Enclosed Coal Storage Sheds — Long-Span Structures for Power Plants & Ports

The regulation that created a structural form. In 2016, China's environmental authorities required the complete enclosure of coal storage at power plants, ports and coking plants, eliminating open stockpiles to control fugitive dust emissions (particulate limits under GB 16297 and the local emission standards that followed). A coal pile that is 100 m wide and 15-20 m high cannot be covered by a 40 m truss — the enclosure must span the whole pile with clearance for the stacking machinery. That single requirement created a market for 90-229 m clear-span structures and pushed the fabrication of beam-string systems and long-span trusses to a new world standard.

The structural forms. Four systems dominate: the beam-string structure (a rigid upper beam restrained by a tensioned lower cable, the form that holds the world record of 229 m that we fabricated for the Huainan project), the three-hinged arch truss (90-150 m spans, triangular cross-section with double-layer chords, 2-3 m structural depth), the two-way truss grid (for very wide bays where the arch is not economical), and the spherical/cylindrical space frame (for uniform sheds with 60-120 m spans). Each form is chosen by the ratio of span to available height, the foundation conditions, and the construction method the site can accommodate.

Coal dust is a design load, not a nuisance. Coal dust accumulation on members creates 0.1-0.3 kN/m² additional load per metre of horizontal projection, and the dust cloud inside the shed is classified per GB 50016 as a combustible dust zone requiring explosion-venting roof panels (0.1-0.2 m² of vent per m³ of volume in the upper 10% of the shed). The structure must also resist the corrosive atmosphere of sulphur-bearing coal (SO₂ and moisture condensation), which drives the protective coating specification to ISO 12944 C5-M or galvanizing with a topcoat.

Machinery rules the geometry. The stacker-reclaimer or bucket-wheel machine travels on rails 30-60 m apart along the shed's full length, and its slewing upper boom sweeps an arc that must clear the roof frame by 1-2 m at every position. The machine's live and dead loads (100-400 tonnes total) act on the foundation through the rails, and its wheel loads of 200-500 kN per wheel must be carried by a rail-grade beam integrated with the shed's longitudinal system. No coal shed is designed without the equipment supplier's load-drawing, because the machine boom's reach defines the free space the roof must not enter.

These combined requirements — 40 m tall, 2,000 m³ of enclosed air per metre, 400 t of moving machinery, and a dust explosion zone at the top — make the enclosed coal shed the definitive test of a fabricator's precision: every one of its 2,000-4,000 members is a unique length in a steel puzzle that must assemble to a 229 m clear span with a closure tolerance measured in tens of millimetres.

Enclosed coal sheds are where Permanent Steel Structure holds its most public records. We designed, fabricated and erected the 229 m clear-span beam-string coal shed at the Huainan project — the longest of its structural type in the world — as EPC, from the environmental assessment geometry to the final cable tensioning. The portfolio also includes the Guodian Ningxia Fangjiazhuang Power Plant enclosed coal shed EPC (a 140 m-class arch truss over a 120,000-tonne stockyard), the Guangdong Huizhou Port Quanwan Terminal enclosed coal yard (port-side storage with dust suppression and direct ship-to-yard rail handling), the Wuzhai 1-million-tonne coal storage and transport project, the Zhuhai Gada Buyi Port 1-million-tonne coal base Phase 1, the Pakistan Tarbela Hydropower and Karot Hydropower coal facilities, and the Shanxi Shentou power generation coal sheds.

The engineering that made the 229 m span possible is the same discipline applied to every shed: wind-tunnel-verified roof pressure coefficients, a rigging schedule that erects without falsework over a live stockyard, full EN 1090-2 EXC3 fabrication control, and a closure tolerance of ±20 mm at the final splice. When your spec sheet says "enclosed coal yard, 150 m span, 120,000 t capacity, stacker-reclaimer on 45 m rail centres," we do not ask if it is possible — we send you the geometry, the member schedule, the cable stressing sequence and the erection program, because that is what we have done at 229.