Loading trailers may seem straightforward but there are a number of critical steps that will dramatically improve the process from a safety and quality perspective.

From a safety perspective, securing the trailer is of utmost importance. Following the steps outlined in the Trailer Pre-load Safety snd Inspection section.

refrigerated transport loading

From a quality perspective, only load “PRE-COOLED Trailers!!!!

Trailer Assignments

The Yardman will need to check with the Dispatch office in order to determine the actual trailer assignments for each load. Based upon the information from the assignment desk, the Yardman will then move the appropriate trailer with a Yard Truck to the designated dock door.

Trailer Pre-load Safety snd Inspection

Before the trailer is backed-in to the dock door, the Yardman should inspect and clean the trailer of any/all debris. The trailer needs to be empty and clean before entering into the dock space.

Once the trailer is clean, the Yardman should check the door seals on the dock door to ensure that are in good condition and are properly position to seal the tail of the trailer.

When the trailer has been properly backed-in to the dock door, the trailer needs to be secured prior to loading. The Yardman should take the following steps:

  • Secure the Glad Hand Locks
  • Secure the Wheel Chocks
  • Ensure the Trailer is properly spotted in the Dock Door
  • Ensure that the Dock Door is not opened until Trailer is spotted and secured

Once the trailer is physically secured and in position to the assigned dock door, the Yardman or other warehouse personnel should take the following steps:

  • Secure the Dock Door Seals
  • Raise the Dock Plate
  • Ensure the Dock Light is “Green” before opening up the trailer door

Now, it is time to check the condition of the trailer compartments and components:

  • Verify Operational Readiness of the Trailer
    • No Debris
    • No Obstructions
    • Cleanliness Check (Free of debris, pest, microbes, etc.)
    • Bulk Head(s) are functional
    • Straps and Load bars (E-tracks) are functional

The final step is to verify that the trailer is properly pre-cooled and operationally ready to be loaded. Checking the reefer set points is not enough to confirm whether or not a trailer is pre-cooled, you must confirm the air temperatures in the forward (nose) section and the back (tail) section of the trailer.

Real-time telematics devices will automatically provide compartmental air temperature verification, however, in the absence of real-time sensors, the Loaders will have to manually probe the trailer with a handheld and properly calibrated temperature device.

  • Verify Pre-Cool Readiness of the Trailer:
    • Confirm Compartmental Temperatures
    • Confirm Reefer Set Points

Reefer Status During the Loading Process

Over the years, there has been a great deal of discussion about whether or not the reefer unit should remain on or be turned off during the loading process. There is no black or white answer to this question because it really depends on the specific environmental conditions of the loading area.

In sifting through the data, it is pretty clear that maintaining consistent temperatures is critically important throughout the distribution process.  Obviously pre-cooling and the loading of properly pre-cooled trailers are essential so the temperatures in the trailers can be properly maintained.


Thermal inertia is the enemy of food distributors and it (thermal inertia) is caused by volatile temperature fluctuations. Turning reefers “On” and “Off” is dependent on the environmental conditions during the loading process.


Turning a reefer unit “off” or lowering the reefer temperature may be okay if the temperature difference between the trailer and the loading dock is minimal.  The larger the difference, the more volatile the environment — which exacerbates the effect of thermal inertia and the loss of shelf life.

No one turns off the compressors of a Cold Storage warehouse when you are running pallets into the freezer section.  Most facilities install automated doors to minimize the temperature variation when the doors are open.  Loading trailers should be looked at in a similar light.

Energy is a funny thing, slow and steady always wins. Continuous temperatures with smaller fluctuations are better than starting and stopping reefers, which will cause larger temperature swings.  In order to save fuel and protects temperature quality – it is always better to be “slow and steady”.

Staging the Product (Pallets) for Loading

Another important step in the loading process is to “Stage the Product (Pallets)” in a loading zone near the loading dock. Essentially, you want to pre-position the pallets in the Cool Dock in order to maximize the efficiency of loading the trailer quickly.

The quicker the loading process, the quicker you can close the trailer doors which will help reduce the thermal loss and the stabilization of consistent temperatures.

Here a few quick steps for staging of products:

  • Verify Jacks and Forklifts are operational
    • Approved equipment types for loading
    • Battery and/or fuel levels
  • Verify Temperatures with properly calibrated devices
    • Cool Dock environment
    • Product pulping temperatures
  • Verify Load and Pallet integrity
    • Cleanliness Check (Free of debris, pest, microbes, etc.)
    • Ensure BOL and shipper requirements and confirm load
    • Ensure that pallets are the proper type for the customer
  • 2-Way; 4-Way; Block; etc.
    • Ensure that pallets are at proper height and will not block normal airflow
    • Ensure proper packaging of products to be transported before loading
    • Identify potential cross contamination issues
    • Stabilize pallets
    • Shrink-wrap pallets
  • Pre-position refrigerated products (pallets) near the dock door
    • Arrange pallets in accordance of loading sequence based on product mix i.e.
  • Last Stop pallets loaded first toward the nose; or
  • Frozen pallets loaded first toward the nose in the frozen compartment; followed by chilled products in the chilled compartment
  • Arrange pallets in accordance with grid/pallet placement diagram (Load Diagram)
  • Provided by a Supervisor

Loading the Trailer

All of the preliminary work has been completed – it is now time to load the trailer in a safe and timely manner ensuring proper airflow to all pallets.

Loader(s) should only use approved Jacks and/or Forklifts to load the trailers. Pallets should be loaded in the proper sequence as defined in the Load Diagram and should utilize the following criteria:

  • Limit access to the trailer during loading to Loader(s) only to ensure safety
  • Load product quickly and efficiently from staging area
  • Reduce surface contact of product with storage area and loading equipment
  • Loading placement should account for proper airflow around all product loaded
    • Reefer return air and discharge air openings should not be blocked
    • Pallets openings should not be obstructed i.e. shrink wrapped
  • Pallet placements should re-enforce the stability of the load
    • Place pallets side be side to avoid tipping during transit
    • Spacer pallets should be used is an empty grid position
  • Bulkheads should be properly secured between frozen and chilled compartment
    • Bulkheads must open for the load to be unloaded safely
    • Secure bulkhead securely into place with strap(s)
  • Load bars and straps should be used to properly secure and stabilize the load
    • Lock and secure E-track connectors
    • Tighten straps and secure loose ends so they don’t touch the floor

Trailer Post-Load Verification and Inspection

Once the trailer is loaded, the Loader(s) should conduct a final review before closing the trailer doors. The post-load checklist is as follow:

  • Verify BOL paperwork
  • Verify all pallets have been loaded
  • Verify Load Diagram
  • Check load for proper airflow
  • Check that bulkheads, load bars and straps are properly secured
  • Close Trailer door, latch, lock and secure door seals

Securing the Loaded Trailers for Staging

The final step in the Loading process is to safely move the trailer to the Staging area of the yard. The loader should complete the following steps:

  • Raise dock plate
  • Close dock door
  • Ensure the dock light turns “Red”
  • Proceed outside wearing a reflective safety vest
    • Remove glad hand lock
    • Remove wheel chocks
  • Ensure any changes or special information for the driver is marked clearly on the load diagram
  • Place load diagram into the route folder and turn-in to the supervisor
  • Notify the Yardman that the trailer is now ready to be moved to the Staging area

Read Stage 1.Pre-Cooling Trailers Process.

Coming next – Staging Loaded Trailers

For more information, please call 1-888-571-7466 (USA), +353 (1) 9036857 (Europe), +86 (20) 28261800 (China).

3 Responses to “BEST PRACTICES FOR REFRIGERATED TRANSPORT©. Part 2. Loading Trailers.”

  1. Taylor Bishop

    I wanted to thank you for this advice for refrigerated transport. It’s good to know that the trailer should be inspected and cleaned of any debris before it’s backed-in to the dock door. It sounds important to make sure that the the trailer is cleaned before and after any use, especially if it affects how efficient it will be.

  2. Ron Booker

    It’s interesting how pre-cooling and the loading of properly pre-cooled trailers are essential so the temperature in the trailers can be properly maintained. My aunt is making a 5 hrs trip and she wanted to know how to properly use a refrigerated trailer for her load to get there properly cooled. Thank you for helping me learn more about refrigerated trailers, I’m going to share this tip her so that she can have an idea also.

  3. Tex Hooper

    I like your trailer tips. I need to get a trailer. I will have to transport my horses soon.


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