Holland Moving & Rigging Supplies or HMR Supplies was approached about designing a custom piece of equipment to transport trees weighing up to 10 Tons. The customer was looking for a solution to planting the Swamp White Oak trees on the elevated 9/11 Memorial plaza.
HMR Supplies designed an SPMT or Straddle Mover (a remote controlled load transport system) to meet the special needs of planting trees on the 9/11 Memorial plaza. It was important for the equipment to be able to carry the tree in the center of all the axles, be capable of traversing sideways and able to negotiate openings on the surface of the plaza. There are also up to 8 stories underneath the plaza for access, equipment and a museum requiring low ground pressure and a wider tire base.
When you see the Straddle Mover up close, on the 9/11 Memorial webcam or on YouTube, it is an impressive site. The knuckle suspension is able to lift and lower the frame and load up to 20 inches. The block and cable system is capable of lowering the load below ground level, and 135 degrees of steering allows the Straddle Mover negotiate the tight quarters on the plaza. A single operator and a remote control maneuver the straddle mover.
Although the Straddle Mover was originally designed for moving trees, it can also be used for bridge deck replacement. An easier method of upgrading the bridge decking will reduce the down time for bridge repair.
HMR supplies has a patent for this invention (number 8733479 B2) that covers the design for a remote controlled load transport system.
