Optimize trailer life and service with doors, tail lifts and floors (2023)

Followers tend to spend more time off base than at home due to its application. For this reason, it is very important to mitigate wear and tear damage associated with the handling, loading and unloading of loads, which can directly impact doors, elevator doors and floors. You can do this by knowing what type of flooring you need to specify.

floor options

Chris Lee, vice president of engineering for Great Dane Trailer, says, "At Great Dane, we consider many factors when recommending a tread option to our customers." Some of the key considerations he mentions are:

• Forklift Axle Load (Load): The industry commonly uses TTMA RP 37.
• Number of Load Cycles Per Day – For high load conditions, Lee recommends a higher floor load.
• Fail Safe Design – The entire trailer bed system, including the floor, cross member attachment links, and rails, must be designed and assembled to withstand concentrated loads without fatigue. Any one component failure can lead to the failure of the entire flooring system.
• Wood spices: Hardwood spices are normally used: oak, maple, apitong, etc. Spices play an important role in the durability of the floor.
• Moisture exchange for waterproofing: The adhesives and sealants applied to the decks are essential to prevent water leaks.
• The siding (top and bottom) must resist damage from weather and road debris.
• Maintenance: Individual circuit boards must be designed and assembled so that they are readily replaceable and readily available.
• Weight – This is an important factor as the floor absorbs most of the weight of the trailer. Today, composite flooring can offer significant weight savings.
• Floor thickness: This affects the weight of the floor and the load capacity. Proper floor thickness must be determined for specific options and weights.

“The most important things to consider when choosing the right trailer floor are the total weight of the payload, the type of product to be loaded, and how the product will be loaded,” said Steve Zaborowski, senior vice president of XTRA Lease. “Fleets need to consider all the elements that contribute to trailer usage, including forklift weight, bed weight, cargo weight, and the number of cycles the trailer takes. Some product applications require more durability and strength than others, such as B. beverage products, paper rolls, and heavy industrial products.”

Traditionally, fleets have specified trailer floor ratings in the 20,000 lb. range. area, with 1 3/8 in. The floors to be built on 12-in. centers. For example, at XTRA Lease, trailers are built for a variety of uses, with trailers specified for durability and strength. XTRA specifies trailers with 1 3/8 in. Oak floors rated up to 24,000 pounds. and built for 10-in. centers. In addition, the XTRA installs a 27-inch monitor. deep sill plate at the point of entry, along with two crossmembers in the last 4 feet of the trailer for added strength, Zaborowski says.

For heavier loads, some fleets may take the weight off the trailer to carry the load. You can choose a combination of wood and composite material to achieve the same strength and reduce dead weight. Fleets can also use aluminum floor panels to reduce weight.

Choosing the right doors

"Most LTL carriers use roll-up ports, while TTL carriers use swivel ports," he says. “Because LTL shippers make frequent stops and open and close multiple doors, they need fast, less labor-intensive roll-up doors. On the storage ramp, the roll-up door is also preferred because drivers do not need to pre-open the door before entering the ramp. TL conveyors often travel long distances and have fewer door opening and closing events, so the revolving door is a better fit for your operations. Here are the challenges:

• Thermal Performance: The thermal efficiency of the door is important for trailers with climate control. In general, swing doors are more thermally efficient than roll-up doors because swing doors offer better sealing.
• On-Highway and Off-Highway Operation: On-highway trailers generally require less door hardware and structural reinforcement for the frame because there is less movement of the trailer (ie frames). However, off-road trailers require more door hardware and frame reinforcement to prevent the rear frame from tipping. Revolving doors generally provide more structural reinforcement to the frame than roll-up doors, so the frame used in revolving doors requires fewer structural elements.
• Door opening dimensions: Hinged doors offer more opening dimensions than roll-up doors due to the lower requirements on the frame structure. Therefore, bulk carriers often use revolving doors.
• Impact resistance: Hinged doors offer better impact resistance due to the geometry of the door and the reinforcement of the hardware.
• Door Hardware – The number of hinges, latch bars, fasteners, and the thickness of the door gap varies greatly depending on the operation of the conveyors.
• Corrosion Resistance – Both the door panel and hardware must be properly coated to resist road salt and chemicals that can cause corrosion.”

“We use a standard 10mm composite panel door material on all of our gullwing vans,” notes XTRA's Zaborowski. “This type of product helps prevent corrosion and damage. By removing the wood material from the door, we are able to offer you a thinner and stronger door. On vans with roll-up doors, we also use composite panels and install guards on the upper doors to prevent damage that can be caused by forklifts loading or unloading.”

level of use

“The duty cycle of the unit has to be the primary consideration,” said Gary Fenton, vice president of engineering for Stoughton Trailers. “Fleets need to understand the method of loading the load, the net force exerted on the ground by the forklift tires, and the imposed load and space requirements of the static load itself. The frequency of uploads per period should also be taken into account. It is also important to know the state of the charge when it is charged [dry, wet, acid, corrosive, etc.]. When considering ports, the following questions should be asked:

• Do the units need to be secured until the trailer is coupled? If this is the case, this would dictate the operation of the roller shutter.
• Should the cargo be relocated or operated by rail? (This can affect the rigidity of the door and the number of latch bars and hinges to be included.)
• What port opening is specified? Are there any insulation requirements?
• What level of security is desired?
• What color scheme or cosmetic coverage is required? Is there a weight consideration?

Elevator doors and structure

The specification of elevator doors has to do with the supplier and type of elevator door: retractable, rail lift, etc. The interface and connection method depend on the brand of the tailgate. Dimensional and strength considerations should be tailored to the specific type and supplier's brand. Thieman engineering director Terry Eyink lists the following considerations as fleet tailgate specifications:

• What is the heaviest load lifted?
• Will this be a typical load, lifted frequently every week or only infrequently a few times a year?
• Are loads usually lowered from bed level or raised off the floor? Each elevator door has an operating bed height range for which it is designed, and deviation from this range can cause problems with ground clearance, inability to reach the ground, etc.
• How many raise/lower cycles does the lift gate make in a typical day?
• How many of these cycles will be consecutive or stopped?
• How much time is spent driving on a typical day?
• Do the trucks have an anti-idling feature? This can help determine if booster batteries are needed and if optional charging methods are required.
• What is loaded on the lift (trucks, pallets, etc.) and how is the load transferred to and from the lift, both at ground level and at platform height?
• Is the trunk lid attached to a spring?
• If the truck is parked at a loading dock and the tail lift is not in use, will the truck or trailer be loaded with a forklift?
• Are truck stops or other options desired for the task at hand? And is a flush elevator door desirable?

According to Great Dane's Lee, the frame of the trailer that the tail lift is installed on must be structurally sound to meet the maximum load capacity of the tail lift. If it is necessary to modify the trailer frame to meet the dimensional requirements of the liftgate, the trailer OEM should be consulted for further modification.

"It's preferable to have rear frames and trailer subframes pre-engineered to accept specific rear lifts," says Lee. “In addition, electrical and plumbing wiring must be considered when designing the trailer for proper installation.” Also note that the rear skid plate must meet NHTSA standards. And the trailer floor must be flush (level) with the tail lift extension plate.

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