Modular Trailer

A modular trailer is a hydraulic multi-axle platform that carries heavy or oversized cargo by combining standardized axle modules into one working unit. Each module is identical in width and height, so operators can couple them side by side or end to end and match the trailer’s capacity to the load in front of them. This is the same modular principle used in SPMT design, minus the self-propulsion. A modular trailer is towed by a prime mover or power pack unit, which makes it a more cost-effective choice for transport jobs that do not require independent module steering or engines.

Shiyun Trailers manufactures modular trailers in 2, 3, 4, 5, 6, and 8 axle line configurations, available as complete modular units or split units depending on how you plan to combine them. Every module uses a hydraulic suspension with a slewing bearing steering system, which keeps the load level and stable even when road surfaces are uneven. The suspension self-adjusts to changing grades and cross falls, and the trailer can self-load and self-unload cargo without extra lifting equipment.

How Axle Line Configurations Affect Capacity

Modular trailer capacity scales directly with the number of axle lines coupled together. A 2-file unit configuration carries roughly 45 tons per axle, a 3-file unit reaches about 67.5 tons per axle, and a 4-file unit reaches around 90 tons per axle. Because modules connect longitudinally and transversely, buyers are not locked into a fixed capacity. The trailer can be reconfigured for a different project simply by adding or removing axle lines.

Frame construction uses high-tensile steel rated at Q690D, which keeps the structure light enough for efficient towing while holding up under repeated heavy loading cycles. Platform width runs around 2990mm with a lifting compensation range of roughly ±300mm, giving the deck enough vertical travel to level out uneven ground during loading and transit.

Modular Trailer vs. SPMT

The main difference between a modular trailer and an SPMT (Self-Propelled Modular Transporter) is the power source. An SPMT carries its own engine, steering, and control system on every module, so it can move under its own power in any direction. A modular trailer relies on an external prime mover or power pack for propulsion, with hydraulic steering built into the modules themselves. For projects that need maximum maneuverability in tight yards, an SPMT is usually the better fit. For long-distance heavy haul where a tractor unit is already part of the operation, a modular trailer is typically the more economical option. Shiyun Trailers manufactures both product lines, so buyers can compare capacity, budget, and site conditions before deciding.

Where Modular Trailers Are Used

Modular trailers are common across heavy industry projects that involve moving equipment too large or too heavy for a standard flatbed or lowbed trailer. Typical applications include:

• Power plant equipment such as transformers, boilers, and turbines
• Wind power components, including nacelles and tower sections
• Shipyard and offshore modules
• Petrochemical and refinery vessels
• Bridge girders and precast infrastructure sections
• Steel mill and heavy machinery relocation

SHIYUN Modular Trailers: Build Quality and Testing

SHIYUN’s modular trailers are compatible with Goldhofer THP/SL type systems, so they can couple and operate directly alongside existing Goldhofer fleets. Beyond compatibility, SHIYUN reinforces the frame chassis for added load capacity and offers modification, troubleshooting, and upgrade services for trailers already in a customer’s fleet.

Production runs through 8 stages: 3D design and material sourcing, frame fabrication with precision welding and stress relief, axle and suspension assembly, hydraulic and control system integration, full assembly, corrosion-resistant painting, load and function testing, and final inspection before packaging. Every unit is tested at 125% to 150% of rated capacity before delivery, along with axle load balancing, hydraulic lifting tests, steering tests, and dynamic running tests. A full test report ships with every trailer.

Standard accessories include a hydraulic gooseneck, drawbar and steering swivel arms, a diesel-powered power pack unit, low-profile drop decks, vessel bridges, spacers, extendable spacers, high girder bridges for loads over 300 tons, and long load turntables for extended cargo.