How to Choose a Grúa Pórtico: MH vs MG vs RMG
If you are equipping an outdoor storage yard, precast plant, rail siding, or container terminal, the gantry crane decision usually comes down to three families: MH single-girder, MG double-girder, and RMG rail-mounted container cranes. They look similar from a distance, but they differ in capacity ceiling, duty class, foundation cost, and how they move. Choosing the wrong one is expensive — not because the crane fails, but because you pay for capability you never use, or you under-specify and hit a wall in year two.
Start With Load, Span, and Duty — Not Price
Three numbers decide the family before you talk to any supplier:
- Maximum lifted load including spreader or lifting beam weight, not just the cargo.
- Effective span — the clear distance between rail centers, which drives girder depth and crane weight.
- Duty class — how many cycles per hour and hours per day. A yard working 8 hours at 6 lifts/hour is a light-duty application; a container yard running 20 hours is heavy duty.
As a working rule: MH single-girder grúas pórtico cover roughly 1–20 t and spans up to about 30 m. MG double-girder grúas pórtico run 5–50 t with wider spans and higher duty cycles. RMG container cranes handle 30–45 t under spreader with spans matched to container stacking lanes. If your load is above 20 t and the crane runs daily, MH is usually the wrong answer.
MH Single-Girder Pórtico: The Cost-Effective Outdoor Workhorse
The MH uses one main girder with an polipasto eléctrico (CD or MD type) running underneath. It is the lowest-cost way to cover an outdoor yard, and for many buyers it is entirely sufficient.
Best for: precast concrete yards, pipe and steel stockyards, small fabrication shops, temporary or rental yards, loading/unloading at rail sidings with moderate throughput.
Practical limits: the hoist is exposed to weather, so rain covers and more frequent wire rope inspection matter. Trolley travel and hook approach are less precise than a double-girder setup. Above roughly 20 t or 30 m span, girder deflection and wheel loads climb quickly, and the cost advantage disappears.
Rail vs wheel: MH cranes are most often rail-mounted on ground rails. A wheel-mounted version on pneumatic tires exists for yards where rails cannot be poured, but it needs a flat, compacted running surface and is not suitable for long travel distances.
MG Double-Girder Pórtico: Higher Capacidad, Better Hook Control
The MG carries a trolley on top of two parallel box girders. That geometry spreads load, reduces deflection, and allows a wider hook approach — the hook can reach closer to the legs, which matters when you are loading trucks at the yard edge.
Best for: steel service centers, heavy fabrication, shipbuilding blocks, waste-to-energy and biomass plants, ports handling general cargo, and any yard lifting 10–50 t on a regular schedule.
What you gain: higher duty cycle capability, better positioning for two-hook or rotating trolley configurations, easier integration of anti-sway and load display systems, and a more stable platform for grabs, magnets, and C-hooks.
What you pay for: more steel, heavier legs, higher wheel loads, and therefore a more substantial rail foundation. Budget the civil work honestly — a 40 t MG can impose wheel loads that require a different rail beam design than a 10 t MH on the same span.
RMG Rail-Mounted Container Pórtico: Purpose-Built for Boxes
RMG cranes are not general-purpose grúas pórtico. They are designed around ISO container handling, normalmente 20 ft and 40 ft, with a telescopic spreader, and they run on dedicated rails along a stacking block.
Best for: inland container depots, rail intermodal terminals, port stackyards, and logistics parks where containers are stacked 3–5 high and moved on a fixed grid.
Key design points: RMG spans are set by the number of container rows plus a truck lane — commonly 6 rows plus 1 lane, which lands around 30–40 m. Lift height is set by stack height plus clearance. Because the crane repeats the same path thousands of times per day, rail alignment, rail fastening, and anti-skew systems are as important as the crane itself.
Rail vs wheel, again: RMG is rail-mounted by definition. Rubber-tired gantry (RTG) cranes offer yard flexibility but cost more to run, need larger travel areas, and are harder to automate. If your yard layout is fixed and you want the lowest cost per container move, RMG is the stronger long-term choice. If you must reconfigure stacking lanes seasonally, RTG deserves a look.
A Quick Selection Checklist
- Under 20 t, moderate use, tight budget → MH single-girder
- 10–50 t, daily use, wide span, need hook reach → MG double-girder
- ISO containers, fixed stacking grid, high cycle count → RMG
- No rails possible, soft ground, short moves → consider wheel-mounted or a different crane type entirely
- Metallurgical or high-heat environment → look at YZ-series metallurgical grúas puente instead of standard gantry designs
Specification Details Buyers Should Confirm in Writing
Ask for the design standard explicitly: GB/T 3811 is the Chinese national basis, while FEM 1.001, DIN 15018, or CMAA #70 may be required by your insurer, consultant, or local authority. Confirm steel grade (Q345B for main girders is standard; Q235B appears in secondary structures), and name the component brands — Schneider, Siemens, ABB, or SEW drives and controls are common requests and affect both reliability and spare-part sourcing.
Also confirm certification scope for your market: CE for the EU, EAC (TR CU 010/020) for Rusia and the EAEU, GCC/SASO for the Gulf, SONCAP for Nigeria, KEBS for Kenia. A crane that meets the mechanical spec but lacks the right certificate can be blocked at port.
Plazo de entrega, Garantía, and Getting a Real Quote
For most standard gantry configurations, production runs 30–45 days after drawing approval. There is no MOQ — single units are normal in this segment. A 12-month warranty is the common baseline. To get an accurate quote rather than a placeholder number, send: capacity, span, lift height, travel length, duty cycle, power supply voltage and frequency, control method (pendant, radio, cabin), and your destination port.
Chunhua Grúa supplies MH, MG, and RMG grúas pórtico plus grúas puente, light rail systems, parking systems, and manipuladores, with 81 standard models across five categories and export experience in 60+ countries. Quotes are returned within 4 hours. WhatsApp +86 193 9277 7259 or email yuhua0095@gmail.com with your load and span figures to start.