What are SPMTs?

SPMTs are used wherever a load is too heavy for road transport, too large for crane handling, or too structurally sensitive to be lifted without distributed support. Bridge girders too long for a low-loader, offshore modules too heavy for road haulage, reactor vessels, port cranes, stadium roof sections and power station components have all been moved by SPMT.

The modern SPMT was commercialised in the early 1980s — Mammoet and Scheuerle introduced the technology in 1983 — originally for port operations and offshore module transportation. It has since become the standard method for load-out operations — moving completed structures from fabrication yards onto barges or offshore platforms.

Per-axle-line capacity and module payload are model-specific and stated by the manufacturer. TII Scheuerle, which developed the SPMT in 1983, publishes axle-line capacities up to 60 tonnes for its current range; Mammoet states a maximum of up to 44 tonnes per axle line for its own fleet. Both are in service, so a capacity quoted without naming the model and configuration is not a usable figure. Lines are coupled in parallel to distribute load across a wider footprint. The coupled array is controlled from a single operator console, with all steering and propulsion synchronised electronically.

The hydraulic suspension system is the key feature. Each axle can travel independently through its vertical stroke, allowing the platform to compensate for ground undulations and maintain controlled load sharing within defined stroke, stability and ground-bearing limits. This allows SPMTs to transport structures that cannot tolerate differential displacement — long bridge girders, precision equipment, large process vessels.

Steering is all-wheel, allowing the complete array to move in any direction — forward, sideways, diagonally — and to perform complex manoeuvres in confined spaces that road vehicles cannot replicate.

Load-out — moving completed modules from the fabrication yard onto barges — is one of the largest SPMT applications. On offshore projects, the load-out programme is on the critical path: delay to SPMT operations delays barge departure, vessel scheduling and offshore installation. Day-rates accumulate across the entire offshore campaign.

Bridge beam installation uses SPMTs to move pre-assembled bridge spans into position overnight on live road networks, replacing crane operations that would require extended road closures.

Industrial relocations use SPMTs to move complete plant items — reactors, heat exchangers, large compressors — between locations within a refinery or petrochemical complex without disassembly.