Case study · Grain storage
Main contractor: CSCEC 5th Bureau (north zone)Tandem lift, 2 × 600 t cranesQ355B
Shenshan 750 kt Grain Reserve: A 47 m Trestle Lifted 50 m High
Steel conveyor trestles and roof steel for a 750,000 t national grain reserve behind Xiaomo Port in the Shenzhen-Shanwei Special Cooperation Zone. The Lot 3 trestle, 47 m long, was lifted in one piece by two 600 t mobile cranes.
750,000 tGrain storage capacity
47 mTrestle span
50 mTrestle height above grade
223,000 m²Gross floor area
01Project facts
Storage, transfer and processing on one port site
The Shenshan grain reserve combines strategic storage, port transfer and emergency processing on a 350,000 m² site behind Xiaomo Port. It uses shallow-round silos, vertical silos and low-temperature warehouse blocks, linked by enclosed conveyor trestles that carry grain between the berth, the silos and the processing buildings.
Guiguan fabricated steel trestles, trestle support towers and roof steel for the storage buildings. The highlight was Lot 3: a 47 m trestle span set 50 m above grade between two silo groups.
Silo and trestle zone during construction
| Item | Detail |
|---|---|
| Owner | Shenshan grain reserve authority (state grain reserve project) |
| Main contractor | China State Construction 5th Engineering Division (north zone) |
| Location | Behind Xiaomo Port, Shenzhen-Shanwei Special Cooperation Zone, Guangdong |
| Building type | Grain silos, warehouses, conveyor trestles, processing plant |
| Site / GFA | 350,000 m² site · 223,000 m² GFA |
| Capacity | 750,000 t of grain |
| Trestle | 47 m span, 50 m elevation, enclosed box-truss gallery |
| Structural steel | approx. 3,800 t across trestles, towers and roofs (estimated) |
| Steel grades | Q355B; Q355C for exposed coastal members |
| Our scope | Detailing, fabrication, trial assembly, coating, delivery, lift engineering support |
| Program | Start December 2022 · operation planned end 2025 |
Tonnage and member data from fabrication records; areas and dates from the owner and main contractor.
02The challenge
A long, light, high span in a coastal wind zone
Conveyor trestles are long and slender. At 50 m above grade on the South China coast, wind and lift stability governed more than grain load.
47 m span at 50 m
The trestle bridged two silo groups with no intermediate support. It had to be stiff enough for conveyor alignment and light enough for a two-crane lift.
Typhoon exposure
Coastal Guangdong design wind pressures, with the gallery cladding adding sail area to the truss.
Live silo interfaces
Trestle ends sat on silo-top structures and towers with tight bearing tolerances and thermal movement.
Lift stability
A long box truss must not twist or overstress during a tandem lift. Lifting points and temporary bracing were part of the design.
Marine corrosion
Salt-laden air near the port called for a heavy-duty coating system and sealed box members.
Dust and fire
Grain dust requires smooth, cleanable steel surfaces and explosion-relief detailing in galleries.
03Engineering solution
A box truss built as one piece, lifted as one piece
The trestle is a rectangular box truss: two vertical Warren trusses for the sides, with top and bottom chord bracing forming a closed tube for torsional stiffness. Chords are welded H-sections; diagonals and verticals are H and tube sections. The conveyor runs on the bottom deck and the gallery is clad on a light frame.
We fabricated the trestle in transportable segments and trial-assembled the full 47 m length in the yard, surveying camber and diagonals before match-marking. On site it was bolted together at ground level, then lifted by two 600 t mobile cranes. Lifting lugs were designed at the panel points so each crane took its share without local buckling. One end bears on a fixed bearing, the other on a sliding bearing to release thermal movement.
Long-span truss in shop trial assembly
| Member / detail | Section & grade | Detailing note |
|---|---|---|
| Trestle chords | Welded H 400×400 to 500×400, Q355B | Bolted splices at segment joints, match-marked |
| Diagonals / verticals | H 250–350 and tube Φ219–299, Q355B | Gusset connections, seal-welded tubes |
| Plan bracing | Angles and tubes, Q355B | Closed tube action for torsion during lift |
| Support towers | Box columns 600×600, Q355C | Four-leg braced towers, HSFG bolted |
| Bearings | Fixed + sliding steel bearings | Sliding end releases thermal movement |
| Lifting lugs | Plate lugs t = 40–50 mm, Q355C | At panel points, 100% UT, removed after lift |
Fabrication & QC, Guangdong base
04Fabrication & QC
Full-length trial assembly before shipping
The full 47 m trestle was assembled in the yard and surveyed for length, camber, diagonal difference and bearing positions. Lifting lugs and their welds received 100% UT and MT and were load-checked against the lift plan. Coating used a C5 marine system: Sa2.5 blasting, zinc-rich epoxy primer, epoxy intermediate and polyurethane top coat, about 240 µm total DFT.
- Full trial assembly of the 47 m span in the shop yard
- Camber and diagonal checks within L/1000
- 100% UT on CJP welds and all lifting lug welds
- C5 marine coating, DFT recorded per piece
- Lift plan reviewed with the crane contractor
05Delivery & erection
From yard assembly to a two-crane lift
The lift took a single day. The preparation took weeks.
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01
Detailing and lift design
Tekla model of trestle and towers; lift points, rigging and temporary bracing checked with the crane contractor.
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02
Shop fabrication
Chords, diagonals and towers fabricated in Q355B; lifting lugs welded and tested.
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03
Trial assembly
Full 47 m span assembled, surveyed and match-marked, then split for transport.
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04
Site assembly
Segments bolted together on a ground jig; conveyor deck and bracing installed before lifting.
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05
Tandem lift
Two 600 t mobile cranes raised the trestle about 50 m and set it on fixed and sliding bearings.
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06
Fit-out
Gallery cladding and conveyor installed; final survey of bearing and alignment.
06Results
One lift, no site modification
47 mSpan lifted in one piece
50 mLift height
2Cranes, 600 t each
750 ktGrain reserve capacity
Because the span was trial-assembled and surveyed in the yard, site assembly was a bolting exercise and the trestle seated on its bearings without modification. Lifting at ground-assembled weight with conveyor deck in place cut high-level work to bearing fixing and cladding.
For port, mining and agri-bulk owners overseas, the same method works for conveyor galleries and transfer towers shipped from South China. See grain and silo structures and coating systems.
07Related
Systems and members used on this project
Each page lists spans, grades and processing limits. See all reference projects.
08FAQ
Questions about this project
Planning a similar structure? Send drawings and our engineers reply within 24 hours.
What did Guiguan supply for the Shenshan grain reserve?
Steel conveyor trestles, trestle support towers and roof steel for storage buildings, including the 47 m Lot 3 trestle. We provided trial assembly, coating and lift engineering support to the main contractor.
How was the 47 m trestle installed?
It was assembled at ground level from trial-assembled segments, then lifted about 50 m in one piece by two 600 t mobile cranes onto fixed and sliding bearings.
What coating do you use for port or coastal trestles?
Typically a C5 system: Sa2.5 blast, zinc-rich epoxy primer, epoxy intermediate and polyurethane top coat, around 240 µm. Hot-dip galvanizing is an option for secondary steel.
Can you ship long trusses overseas?
Yes. Trusses are trial-assembled to 90 m, split into segments up to 24 m and 60 t for break-bulk, and match-marked for site assembly.
Do you design the trestle or build to our drawings?
Both. We fabricate to your design, or our engineers develop connection design and lift checks to AISC 360, EN 1993 or AS 4100 for your engineer’s approval.
Send your drawings. Get a 24-hour BOM and FOB price.
DWG, IFC, Tekla or PDF. Engineering review by our Tekla team, from 50 t or 2,000 m².