Use Safety Chains and Prepare for Transport
- Explain the backup role of safety chains.
- Verify chain routing, attachment, and highway requirements.
- Apply safe towing, unhitching, and storage precautions.
- Flashlight — Illuminate chain links, attachment locations, and the underside of the tongue during inspection.
- Inspection mirror — View concealed portions of chain attachments without placing yourself beneath unsecured equipment.
- Shop rag — Remove surface dirt so chain links and attachment hardware can be inspected.
- Wheel chocks — Help prevent rolling when parking or preparing to unhitch.
Safety chains provide a retained connection if the primary attaching system separates. The source specifically rejects elastic or nylon/plastic tow straps as substitutes for safety chains. Public-highway use also requires attention to state and local chain and auxiliary-lighting regulations.
Route the chains in a crisscross beneath the trailer tongue. The source identifies the drawbar cage, mounting loops, or bumper frame as attachment locations. Follow the applicable requirements rather than treating a tow strap as an equivalent backup connection.
Towing changes the vehicle's stopping and turning needs. Reduce speed for the added weight, allow for overall length, slow before turns, and remain in gear for engine braking downhill. Observe bridge loading limits and check overhead and side clearances.
When stopping operation or unhitching, stop the vehicle, set the brakes, shut down the engine, and remove the key. Park on a hard, level surface and engage safety devices; wheel chocks may be needed to prevent rolling. Store the unit away from human activity and do not allow children to play on or around it.
How It Works
Safety chains retain a separated connection
Safety chains provide a retained connection if the primary attaching system separates; they do not make an unsecured primary connection acceptable. Route them in a crisscross beneath the tongue and use the source-identified drawbar cage, mounting loops, or bumper frame as applicable. Elastic or nylon/plastic tow straps are not substitutes, and public-highway operation requires checking applicable state and local chain and auxiliary-lighting regulations.
Trailer weight and length change vehicle response
Added trailer mass increases the energy that must be managed when slowing, while overall length changes the space needed for turns and clearance. Reduce speed for the added weight, allow for overall length, slow before turns, and remain in gear for engine braking downhill. Observe bridge loading limits and check overhead and side clearances rather than assuming the tow vehicle's clearance is sufficient.
Secure the equipment before releasing the connection
Before unhitching, stop the vehicle, set the brakes, shut down the engine, and remove the key. Park on a hard, level surface, engage safety devices, and use wheel chocks if needed to prevent rolling; releasing the connection can otherwise allow uncontrolled movement. Store equipment away from human activity and prevent children from playing on or around it.
Step-by-Step Procedure
0/7 doneDiagnostic Chart
| Symptom | Check | Spec / Expected | Likely cause & fix |
|---|---|---|---|
| A tow strap is installed as the backup connection. | Identify whether the backup connection uses safety chains or an elastic or nylon/plastic tow strap. | Use safety chains rather than elastic or nylon/plastic tow straps. | A recovery or towing accessory has been treated as equivalent to the required safety-chain connection. Basis: Demco-Coupler-Manual-1 |
| Chains run alongside the tongue without crossing, or their attachment location is uncertain. | Trace the chains beneath the tongue and identify their attachment locations; check applicable state and local requirements. | Crisscross the chains beneath the tongue. The source identifies the drawbar cage, mounting loops, or bumper frame as attachment locations. | Incorrect routing or use of an attachment location not established as applicable. Basis: Demco-Coupler-Manual-1 |
| A chain link or attachment appears cracked, distorted, or heavily worn. | Clean and visually inspect accessible links and attachments for cracks, deformation, wear, and corrosion; resolve suspected damage before towing. | The supplied lesson gives no damage limits; obtain applicable manufacturer inspection and replacement criteria. | Overloading, abrasion, or corrosion may have weakened the backup load path. Basis: General shop practice |
| The operator is preparing to unhitch while the equipment remains unsecured. | Verify vehicle stop, brake application, engine shutdown, key removal, parking surface, safety devices, and need for wheel chocks. | Before unhitching, stop the vehicle, set the brakes, shut off the engine, and remove the key. Park on a hard, level surface, engage safety devices, and use wheel chocks if needed. | The stopping and parking precautions have not been completed before releasing the connection. Basis: Demco-Coupler-Manual-1 |
At the Bay: Diagnose the Case
CASE 1 / 4
A tow strap is installed as the backup connection.
- Test
- Compare
- Correct
Select the next check
Basis: Demco-Coupler-Manual-1. A likely cause is a hypothesis; confirm it with the applicable service procedure before repair.
Common Bay Mistakes
- ✕ Treating safety chains as permission to tow with an unsecured primary connection.
- ✕ Substituting an elastic or nylon/plastic tow strap for safety chains.
- ✕ Choosing speed and turns as though the trailer adds no weight or length.
- ✕ Unhitching before securing the equipment against movement.
Quick Check
Practice only — not scored.
Plan the Service Sequence
Planning practice only. Follow the applicable manufacturer's instructions, employer safety program and qualified supervision on real equipment.
Plan the first action. Compare the service steps with the bay mistakes.
Source: Demco-Coupler-Manual-1 — 5-6