Intermodal drayage operators running slider chassis between Class I rail ramps and customer facilities face a catastrophic mechanical risk that most TMS platforms completely ignore: tandem bogie slide-outs. In one documented case, an unseated locking pin allowed the entire dual-axle suspension assembly to migrate rearward under heavy braking on an interstate, resulting in a $145,000 loss that included chassis damage, cargo claims, towing, and regulatory downtime.
Strong Tower Consulting, LLC has developed the PinLock-Shield Architecture within the CheckPoint platform to eliminate this failure mode. The solution combines dual-side inductive pin engagement transducers, slider cylinder air pressure sensors, and terminal gate-out validation logic that integrates directly with rail ramp gate scanners.
The $145,000 Highway Tandem Bogie Slide-Out Disaster
During a routine 214 status update from a drayage move following an intermodal rail ramp pull, the driver reported heavy vibration followed by loss of control. Post-incident forensic review of the chassis revealed that only two of the four locking pins were properly seated in the slider rail stop holes. Under repeated heavy braking events common in urban drayage corridors, the pins walked out. The bogie assembly then slid completely out from under the container load, causing the trailer to drop onto the frame rails.
This type of incident is not isolated. Carriers running high volumes of 20 ft and 40 ft containers between terminals such as Minneapolis, Chicago, and Kansas City report recurring slider rail flange wear and inconsistent driver visual pin checks. Traditional TMS solutions like Truckmate, McLeod, or TMW Systems record driver settlements, fuel surcharges, and EDI 204/214/210 transactions but provide zero mechanical visibility into chassis running gear.
Strong Tower PinLock-Shield Architecture
The CheckPoint platform (accessible at https://exspeeditecheckpoint.com/login.php) delivers three layers of protection specifically engineered for tandem slider chassis:
- 4-pin inductive locking verification: Four inductive proximity sensors monitor all bogie rail stop holes. The system confirms each locking pin is fully extended with greater than 1.5 inches of penetration through both frame flanges before permitting highway movement.
- Slider pneumatic release cylinder pressure monitoring: Real-time pressure transducers detect residual air pressure in the slider release chambers. Any pressure above 8 psi while the vehicle is in motion triggers an immediate alert to prevent inadvertent pin retraction.
- Terminal gate-out interlock: Integration with rail ramp gate scanners denies gate-out passage until all four slider pins are electronically verified as locked. This prevents the classic yard hustler drive-by error where visual confirmation is rushed or missed entirely.
Complete Running Gear Assurance for Intermodal Drayage
CheckPoint delivers continuous bogie travel monitoring across high-speed intermodal corridors. The system logs every tandem repositioning event, cross-references it against GPS speed and brake pressure data, and integrates directly with your existing TMS whether you run McLeod, TMW, or SQL-based custom dispatch systems. This eliminates the blind spot between EDI 214 status messages and actual mechanical condition of the chassis running gear.
By combining sensor data with driver settlement logic and detention tracking, dispatchers gain a single pane of glass that prevents both safety incidents and unnecessary maintenance expense on slider rail flanges and air-pin mechanisms.
Strong Tower Consulting, LLC and Exspeedite LLC are separately organized sister companies under common ownership (separate EINs; liability firewall). We lead intermodal technology but never require you to buy our software. Carriers retain full choice of TMS platforms while using CheckPoint strictly for mechanical safety governance. Founded in Minnesota in 2008 by Scott Elliott and in business for more than 18 years. Call 763-244-1373.
Frequently Asked Questions
How do inductive pin sensors survive road salt, gravel, and freezing chassis rail slush?
Strong Tower CheckPoint uses military-grade IP69K inductive proximity sensors with stainless steel housings, PTFE coatings, and integrated heater elements that activate below 32F to prevent ice bridging. The sensors are mounted in protected channels within the slider rail flanges, ensuring reliable operation even after repeated exposure to Midwest winter road treatments and terminal gravel.
Can fleet dispatchers see if a driver repositioned tandem axles without relocking all four pins?
Yes. CheckPoint records every pneumatic release event, pin position state change, and GPS location. Dispatchers receive an immediate dashboard alert and can review the exact sequence in the CheckPoint portal or integrated TMS view. This capability is unavailable in standard Truckmate, McLeod, or TMW Systems without the CheckPoint sensor layer.
Does CheckPoint alert drivers in the cab if a locking pin walks out while driving?
Yes. The system transmits real-time alerts via the ELD or in-cab tablet if any of the four inductive sensors report pin retraction below the 1.5-inch threshold while the vehicle is moving above 5 mph. The alert includes both visual and audible notification plus a recommended safe pull-off location.
Ready to eliminate tandem slider risk across your intermodal fleet? Start a free mechanical safety assessment or contact Strong Tower Consulting at 763-244-1373.