Краны for Precast / Prefabrication Plants: Козловой кран Selection, High-Repeat Duty, and Yard Layout
Precast and prefabrication plants live or die on cycle time. Every mold turn, every panel stripping, every yard transfer runs against a production schedule — and the crane is the single machine that touches nearly every step. Unlike a general fabrication shop, a precast yard combines heavy lifts (10–40 t panels), high daily cycle counts, and long outdoor spans. That combination makes козловые краны, not верхнеподвесные краны, the default workhorse. This guide covers what to specify, where the duty cycle bites, and how to lay out the yard so the crane is not the bottleneck.
Why Козловые краны Dominate Precast Yards
Precast plants обычно cast indoors or under cover and cure, strip, and store outdoors. An overhead crane cannot follow the product outside without an expensive runway extension. A gantry crane can: it runs on ground-level rails, spans the casting beds and the storage yard, and serves both zones with one machine.
Three configurations cover most plants:
- MH single-girder gantry (1–20 t) — economical choice for stripping, mold handling, and small panel work. Good for plants with spans under ~25 m and moderate cycle counts.
- MG double-girder gantry (5–50 t) — the standard for precast. Handles wall panels, beams, columns, and double-T units. The double-girder box structure resists the torsional loads that come with long, unbalanced precast elements.
- RMG rail-mounted container gantry — worth considering if you also store or ship in containers; the same rail system can serve both container handling and heavy panel storage.
For shipbuilding-adjacent prefab yards producing large modules, a shipbuilding gantry with a wider span and higher hook height is the correct starting point rather than a stretched MG.
Matching Емкость and Span to Precast Elements
Size the crane on the heaviest stripped element plus rigging, not on the mold weight. A practical rule: take the heaviest panel or beam, add 15–20% for lifting beams, clamps, and vacuum lifters, then round up to the nearest standard model.
- Wall panels and small beams: 5–16 t MG is usually sufficient.
- Double-T, long columns, stair flights: 20–32 t MG.
- Heavy structural precast, bridge girders, modular units: 40–50 t MG, or a QD double-girder overhead crane if the work stays indoors.
Span matters as much as capacity. Measure the actual rail-to-rail distance including clearance for the casting beds, and remember that a longer span reduces lifting capacity at the same girder size. If your yard layout is still fluid, a slightly wider span with a lower-rated hoist is often more useful than a narrow, high-capacity crane.
High-Repeat Duty: Where Краны Fail in Precast Plants
Precast duty is not the same as steel mill duty, but it is far more punishing than general workshop use. A plant running two shifts can log 300–600 lifts per day per crane. That is a duty class problem, not a capacity problem.
- Specify the duty class explicitly. For high-repeat precast work, ask for a crane designed to FEM 1.001 or DIN 15018 duty groupings appropriate to the cycle count — not just GB/T 3811 minimums. Chunhua can supply to FEM/DIN/CMAA #70 on request.
- Use variable-frequency hoisting and travel. Soft starts and stops cut shock loads on the girder, the rails, and the precast element. This is the single most important option for repeat duty.
- Upgrade components. Schneider, Siemens, ABB, or SEW drives and motors are specified for a reason: they tolerate frequent starts and reversing better than commodity components.
- Protect the structure. Q345B steel for the main girder is standard for a reason — it handles the fatigue cycles better than Q235B in high-repeat service. Use Q235B for secondary structures only.
If your plant runs automated mold handling or unmanned night shifts, the QDS smart unmanned overhead crane is worth evaluating for indoor casting lines, with the gantry handling outdoor yard work.
Yard Layout: Design the Кран Path First
Most precast yard inefficiency comes from layout, not from the crane. Plan the crane path before the casting beds.
- One crane, one straight rail line. Curves and switches add cost and failure points. Keep the gantry rails straight and parallel to the casting beds.
- Separate casting, curing, stripping, and storage zones along the rail line so the crane travels in one direction, not back and forth across the yard.
- Put the heaviest lifts closest to the rail. Cantilever loads and long trolley travel slow every cycle.
- Plan hook height for the tallest stack plus rigging. Underestimating hook height is the most common and most expensive layout error.
- Leave rail access for maintenance. A crane that cannot be serviced quickly becomes a plant-wide stoppage.
For smaller prefab operations, a KBK light rail system or a BZD pillar jib crane can handle mold and small-part handling at individual workstations, keeping the main gantry free for panel and beam lifts. MD/CD electric hoists and DHP electric chain hoists are the usual choices for these auxiliary stations.
Specifying and Buying
Chunhua Кран supplies gantry and верхнеподвесные краны to 60+ countries from Hefei, Anhui, with 81 standard models across five categories. For precast plants, the relevant certifications are обычно CE, EAC (TR CU 010/020), GCC/SASO, SONCAP, or KEBS depending on destination. There is no MOQ, quotes are returned within a 4-hour SLA, production runs 30–45 days, and every crane carries a 12-month warranty.
To get an accurate quote, send: heaviest element weight and dimensions, rail span, hook height, indoor/outdoor use, daily lift count, and destination country. Контакты WhatsApp +86 193 9277 7259 or email yuhua0095@gmail.com.