Deep South was highlighted in American Cranes & Transport magazine's feature on SPMTS. The full article follows Deep South's excerpt.

The self-propelled modular transporter (SPMT) is a critical tool in many industry sectors worldwide. With independently controlled axles, they are capable of motion in all directions, even 360-degree movement, and can compensate for uneven ground.

Custom job

In support of a plant upgrade, a petrochemical company in Louisiana needed to transport several large vessels from a cargo ship to their site. The weight and height of three of these vessels posed challenges for the contractor in the way of severe height restrictions from a pipe rack along a public road.

Deep South crews rolled the vessels off barges onto two separate double wide 18 lines (36 lines total) and staged them on cans and mats.

Two of the vessels weighed 919,328 pounds and extended 105 feet long, 19 feet 9 inches tall and 25 feet 2 inches wide, respectively, and the third weighed 859,801 pounds and was 100 feet 11 inches long, 19 feet 8 inches tall and 25 feet 2 inches wide. The combined trailer and vessel weight of the largest would be 1,248,000 pounds, 142 feet 11 inches long, 25 feet 2 inches wide and 19 feet 10 inches tall (at lowest stroke) with another two inches for mid stroke.

Standard SPMT transporters were not suitable for the scope and scale of this transport given the height challenges. Instead, Deep South custom designed a SPMT for safe hauling.

Split configuration

Typically, “split-configuration” SPMTs are divided down the middle of the spine beam of a single file trailer, allowing the trailer to widen and using bolt-in cross beams to increase stability. For this project, Deep South reconfigured a split-configuration SPMT, removing the crossbeams and installing specially designed saddles that allowed the vessels to sit inside the split trailer configuration to reduce the overall transport height.

To use the specialized split configuration, state regulations required Deep South to extend the trailer to meet weight-per-tire permit limits. Potential trailer deflection due to the longer length was resolved with custom-designed and fabricated bolt-on skirt beams that placed weight from the tail end of the vessel to the trailer. Deep South attached standard double-wide four lines at the split trailer power packs to increase side-to-side stability. The total width of the trailer was 25 feet, tire-to-tire, allowing the vessel to sit inches above the ground for maximum height reduction.

Deep South reconfigured a split-configuration SPMT, removing the crossbeams and installing specially designed saddles that allowed the vessels to sit inside the split trailer configuration.

With the custom split trailer SPMTs designed and approved, the transport project moved forward. Deep South crews rolled the vessels off barges onto two separate double wide 18 lines (36 lines total) and staged them on cans and mats. An 800-ton gantry lifted each vessel from the double-wide trailers onto the custom split trailers.

Increased ground stability

The majority of the transport was along a double-lane road. Road plate and laminated mats were placed off-road to increase ground stability. Once near the pipe rack, which was located close to a railroad track, mat pads were laid before and after railroad tracks to smooth out the elevation changes.

While the trailer had less than 6 inches of clearance near the pipe rack and less than 2 inches of clearance from saddles to rail tracks, the move went off without a hitch.