10 hours ago
A multi-axle rig hauling industrial gas equipment through Butler, Pennsylvania demonstrated the complexity of coordinated steering and axle weight distribution in oversize load transport. With an estimated gross weight between 500,000 and 900,000 lbs and a total length approaching 200 feet, the convoy required precise maneuvering and hydraulic steering control to navigate urban intersections.
Oversize Load Transport and Industry Background
Oversize load hauling is a specialized segment of the transportation industry involving cargo that exceeds legal dimensions or weight limits. Common loads include transformers, refinery vessels, bridge beams, and industrial machinery. Companies like Mammoet, Barnhart, and Joe Supor have built reputations for moving extreme loads across highways, ports, and job sites.
The rig observed in Butler was marked with “BOC Gases,” indicating the cargo was likely part of a cryogenic or industrial gas delivery system destined for a steel mill. BOC, originally British Oxygen Company, is now part of Linde Group, a global leader in gas technologies. Transporting such equipment requires coordination between logistics firms, state departments of transportation, and law enforcement escorts.
Terminology Note
The rig encountered difficulty making a turn near a freshly milled street. The rear steering system appeared to malfunction, forcing the driver to back up repeatedly. The coordinated steering system, similar to that used on Roadtec milling machines, allows the rear axles to counter-steer, reducing the effective turning radius. Without it, the rig’s rear end swings wide, risking curb strikes and traffic obstruction.
The operator reportedly considered crab steer mode, which might have allowed smoother lateral movement. However, crab steer is rarely used in urban settings due to unpredictable tracking and increased side load on tires.
Axle Load and Pavement Impact
The convoy’s passage over the milled street was described as the heaviest proof roll the operator had ever witnessed. While exact axle weights were not disclosed, such rigs often use:
Recommendations for Urban Oversize Routing
In New Jersey, Joe Supor’s fleet moved a 600,000 lb reactor vessel using a 22-axle trailer with coordinated steering. The rig navigated a 90-degree turn in downtown Newark with only 6 inches of clearance on each side. The rear steering was controlled by a joystick operator riding in a chase vehicle, communicating via radio with the driver.
In Texas, a similar load caused pavement cracking after passing over a newly milled road. Engineers later determined that the proof roll exceeded the compaction tolerance, requiring rework and delaying the project by three days.
Conclusion
Oversize load transport demands precision, planning, and specialized equipment. Coordinated steering and axle load management are critical for navigating urban environments and protecting infrastructure. As industrial cargo grows in size and complexity, the transportation industry must continue innovating in steering systems, suspension control, and route planning to ensure safe and efficient delivery.
Oversize Load Transport and Industry Background
Oversize load hauling is a specialized segment of the transportation industry involving cargo that exceeds legal dimensions or weight limits. Common loads include transformers, refinery vessels, bridge beams, and industrial machinery. Companies like Mammoet, Barnhart, and Joe Supor have built reputations for moving extreme loads across highways, ports, and job sites.
The rig observed in Butler was marked with “BOC Gases,” indicating the cargo was likely part of a cryogenic or industrial gas delivery system destined for a steel mill. BOC, originally British Oxygen Company, is now part of Linde Group, a global leader in gas technologies. Transporting such equipment requires coordination between logistics firms, state departments of transportation, and law enforcement escorts.
Terminology Note
- Coordinated Steering: A system where front and rear axles steer in opposite directions to reduce turning radius.
- Proof Roll: A test pass over freshly milled or compacted pavement to verify structural integrity under load.
- Hydraulic Steering Failure: A condition where the rear steering system loses pressure or control, causing tracking errors.
- Crab Steer: A steering mode where all axles turn in the same direction, allowing lateral movement.
- Axle Load Distribution: The calculated weight carried by each axle group, critical for bridge and pavement safety.
The rig encountered difficulty making a turn near a freshly milled street. The rear steering system appeared to malfunction, forcing the driver to back up repeatedly. The coordinated steering system, similar to that used on Roadtec milling machines, allows the rear axles to counter-steer, reducing the effective turning radius. Without it, the rig’s rear end swings wide, risking curb strikes and traffic obstruction.
The operator reportedly considered crab steer mode, which might have allowed smoother lateral movement. However, crab steer is rarely used in urban settings due to unpredictable tracking and increased side load on tires.
Axle Load and Pavement Impact
The convoy’s passage over the milled street was described as the heaviest proof roll the operator had ever witnessed. While exact axle weights were not disclosed, such rigs often use:
- Jeep and dolly configurations to distribute weight across 10 to 20 axles.
- Hydraulic suspension systems to adjust load dynamically during turns and elevation changes.
- Load cells and onboard telemetry to monitor axle pressure and pavement impact.
Recommendations for Urban Oversize Routing
- Use coordinated steering systems with real-time feedback to prevent rear-end drift.
- Equip rigs with crab steer override for tight urban turns, but train operators thoroughly.
- Conduct pavement analysis before routing over freshly milled or compacted surfaces.
- Install axle load sensors and share data with DOT officials during transit.
- Maintain hydraulic steering systems rigorously—failure during a turn can cause multi-lane blockage.
In New Jersey, Joe Supor’s fleet moved a 600,000 lb reactor vessel using a 22-axle trailer with coordinated steering. The rig navigated a 90-degree turn in downtown Newark with only 6 inches of clearance on each side. The rear steering was controlled by a joystick operator riding in a chase vehicle, communicating via radio with the driver.
In Texas, a similar load caused pavement cracking after passing over a newly milled road. Engineers later determined that the proof roll exceeded the compaction tolerance, requiring rework and delaying the project by three days.
Conclusion
Oversize load transport demands precision, planning, and specialized equipment. Coordinated steering and axle load management are critical for navigating urban environments and protecting infrastructure. As industrial cargo grows in size and complexity, the transportation industry must continue innovating in steering systems, suspension control, and route planning to ensure safe and efficient delivery.
