Interstate 40DLA Tag Trailer Ramps and the Mechanics of Low-Profile Loading

[MikePhua]

The Interstate Trailer Legacy and the 40DLA Platform
Interstate Manufacturing, based in Idaho, has built a reputation for producing durable tag trailers designed for hauling compact and mid-sized construction equipment. The 40DLA model is a low-profile, dual-axle tag trailer engineered for machines such as skid steers, mini excavators, compact dozers, and small pavers. With a deck height under 32 inches and a gross vehicle weight rating (GVWR) of 40,000 lbs, the 40DLA offers a balance of accessibility, strength, and maneuverability.
The trailer’s design emphasizes ground clearance, ramp geometry, and load distribution. Its heavy-duty I-beam frame and pierced deck construction allow for a lower center of gravity, improving stability during transport and loading.
Terminology annotation:

• Tag trailer: A trailer that connects to a truck via a pintle hitch and rides entirely on its own axles, without support from the towing vehicle.
  
• Pierced deck: A trailer deck design where crossmembers pass through the main frame rails, lowering the deck height.
  

In a paving crew in Tennessee, the 40DLA became the go-to trailer for moving compact rollers and tack distributors between urban job sites, thanks to its low approach angle and robust ramp system.
Ramp Design and Loading Dynamics
The ramps on the 40DLA are critical to its functionality. Typically constructed from structural steel with welded traction bars, the ramps are spring-assisted and hinged at the rear of the trailer. Their length and angle determine the ease of loading low-clearance machines.
Ramp specifications:

• Length: 6 to 8 feet
  
• Width: 18 to 24 inches per ramp
  
• Material: High-strength steel with anti-slip surface
  
• Assist: Spring or hydraulic lift
  
• Angle: 12–15 degrees depending on deck height
  

Terminology annotation:

• Spring-assisted ramp: A ramp equipped with torsion or coil springs to reduce lifting effort.
  
• Approach angle: The angle formed between the ramp and ground, affecting how easily machines climb onto the deck.
  

In a landscaping operation in Oregon, a compact track loader with a low belly pan scraped on a competitor’s trailer ramp. Switching to the 40DLA with longer ramps eliminated the issue and reduced loading time by 40%.
Ramp Failures and Field Modifications
Despite their robust design, trailer ramps can fail due to overloading, improper use, or fatigue. Common issues include:

• Bent ramp arms from side loading
  
• Broken hinge pins due to rust or impact
  
• Traction bar detachment from weld fatigue
  
• Spring failure leading to uncontrolled drop
  
• Ramp bounce during transport if not secured
  

Field modifications often include:

• Adding expanded metal or cleats for better grip
  
• Reinforcing hinge areas with gussets
  
• Installing hydraulic lift cylinders for smoother deployment
  
• Welding side guides to prevent off-center loading
  
• Using locking pins or chains to secure ramps during transit
  

Terminology annotation:

• Gusset: A triangular reinforcement plate used to strengthen joints.
  
• Cleat: A raised strip or bar added to surfaces for traction.
  

In a demolition crew in Pennsylvania, a 40DLA ramp was modified with bolt-on rubber pads to reduce noise and vibration when loading concrete saws. The change also improved grip in wet conditions.
Safety Considerations and Best Practices
Ramp-related injuries and equipment damage are preventable with proper technique and maintenance. Operators should follow consistent loading protocols and inspect ramps before each use.
Safety checklist:

• Verify ramp pins and hinges are secure
  
• Ensure ramps are fully deployed and level
  
• Use spotters when loading large or blind machines
  
• Avoid sudden throttle during ascent
  
• Clean ramps of mud, oil, or debris before use
  
• Secure ramps with chains or pins during transport
  

Recommended upgrades:

• LED ramp lighting for night loading
  
• Reflective tape for visibility
  
• Non-slip coating for wet weather use
  
• Ramp angle indicator for precision alignment
  

Terminology annotation:

• Spotter: A person who guides equipment operators during loading or maneuvering to prevent accidents.
  
• Ramp angle indicator: A visual gauge showing the incline of the ramp, useful for low-clearance machines.
  

In a municipal fleet in Michigan, installing LED ramp lights on all tag trailers reduced nighttime loading incidents by 60% over two seasons.
Maintenance and Longevity
To extend the life of trailer ramps, regular maintenance is essential. Rust, vibration, and repeated impact can degrade components over time.
Maintenance schedule:

• Weekly inspection of welds and hinge points
  
• Monthly lubrication of pivot pins and springs
  
• Quarterly repainting or touch-up of anti-slip surfaces
  
• Annual replacement of worn traction bars
  
• Immediate repair of bent or cracked components
  

Terminology annotation:

• Pivot pin: A steel rod that allows rotation between two connected parts, such as a ramp and trailer frame.
  
• Anti-slip surface: A textured or coated area designed to prevent slipping during loading.
  

In a rental yard in Texas, trailers with scheduled ramp maintenance had 30% fewer downtime incidents compared to units with reactive service.
Conclusion
The ramps on the Interstate 40DLA tag trailer are more than just access points—they’re engineered interfaces between ground and deck, between operator and machine. Their geometry, strength, and adaptability define how efficiently and safely equipment moves from site to site. With thoughtful design, regular upkeep, and smart modifications, these ramps become silent partners in the rhythm of construction logistics. In the world of hauling, every angle counts.