Not all freight is the same size. That’s why when a truck is loading up on tall freight, it’s important that the trailers carrying it are short. This is where the ‘drop deck’ comes in.
Drop decks are a specific variant of flatbed or platform trailer. Going by either ‘single drop or ‘step decks’, these down-step flatbed or platforms offer up an additional 20 inches or more of vertical space to accommodate things like large steel or aluminum coils.
Drop decks are also used to haul things like:
- Large mechanical gear
- Outsized electrical gear
- Farm equipment or other large agricultural materials
- Aircraft engines
- Heavy vehicle equipment parts
For extremely large or heavy loads, a ‘double drop’ offers up an even lower deck than the standard 20-inch clearance and provides an up-step just ahead of the rear tandem.
As an example, lower main decks of high-strength aluminum drop-deck trailers can carry more stacked racks than a regular flatbed might. Although they don’t always need to be composed of high-strength aluminum, they can also come in hybrid steel/aluminum varieties.
The purpose of a low main deck is primarily the lower center of gravity. Taller loads require a lower center of gravity for stability purposes, especially on windy mountain roads or in heavy winds.
The full depth of a flatbed’s understructure is designed to match the height of the truck’s fifth wheel; thus, it is tapered at the front end. This also takes into consideration that less strength is needed at the trailer’s front end.
You can also expect a drop deck’s underframe to likewise taper towards the rear, this time in an upward position. Not only is less strength needed in this position, it adds extra space for the taller cargo.
Because a drop deck has a low main deck, you can also expect to see smaller – though no less strong – wheels underpinning the trailer. Instead of the usual 22.5 inches, drop deck wheels generally come in between 17.5 and 19.5 inches. Still, because a drop deck has a high rear deck, 22.5 inch wheels can still be used, though they are the less-utilized option.
While drop decks are not needed for most freight – as they cannot carry such items as long pipes (unless risers are used) – they are especially useful in situations where dense cargo – such as lumber and shingles – need shipping. Such items can be carried on either the forward, main or rear deck of a double drop. The fact is, these trailer types offer a ton of versatility for certain cargo types.
The Materials Involved In Drop Deck Trailer Manufacturing
The main characteristic of a drop deck is in what is referred to as the “transition” area. The main difference in transition drop decks are the materials used in them. Steel is quite hard, and when gusseted well, it can take stresses up to a full 90-degree bend.
Aluminum is a softer metal and – as such – must build a radius beneath the drop deck to evenly distribute the weight on the upper and lower deck structures. This way the drop deck avoids specifically concentrated stress points and avoids cracking or potential failure while under load.
While aluminum is great for reducing trailer weight, it does – of course – need greater engineering to achieve the same strength as steel. As a result, an aluminum member is both thicker and taller. Expect an aluminum drop deck frame to be – on average – one inch taller than a comparable steel frame.
But what about a flatbed, you may be asking? On a regular flatbed, the taller frame can be accommodated under the trailer, so there’s no need to modify the deck height.
As you go about deciding what type of drop deck to choose, aluminum, steel or a hybrid version, it will depend on the specific operating requirements and financial considerations. Aluminum trailers weigh far less than steel, to the tune of anywhere from 1,100 to 1,400 pounds.
When you’re talking weight savings like those, the first things that come to mind are increased payload capacity and higher revenue numbers. Just make sure you consider that not all freight requires lightweight trailers. Depending on your application, steel or hybrid drop decks might be perfectly adequate for what you are trying to do.
Taking Usage Type Into Account
What makes steel the preferred drop deck and flatbed material for many fleets is the sheer pounding it can take. In some situations, specific materials must be designed for specific trailers.
Take wind turbines blades, generator nacelles and towers as examples. Due to the specialized design of these components, they can’t be loaded on just any old flatbed or drop deck. This is where steel comes in. Weight isn’t an issue here, especially considering these loads are often delivered under special permit.
Is your fleet operating in a geographical region where road salts or de-icing material is often used? If so, the geography of an area should impact your materials choice. Aluminum is generally more corrosion-resistant than steel, which is why you may find these variants used in the northeast and Midwest. Fleets in the Midwest also prefer hybrid trailers using steel beams buttressing aluminum decks and crossmembers. In the South, where there are no salt or de-icing issues, steel is more prevalent.
On van-type trailers, we are starting to see galvanized steel and special coatings applied to the trailer. For obvious reasons, these options are far more resistant to paint and corrosion.
When adding extra protection for steel trailers, not only are you avoiding general deterioration, but you are increasing its overall lifespan and potential resale value down the proverbial road
Assessing Cost Versus Value Over the Long Term
Cost considerations ascend from steel to hybrid combinations to aluminum varieties, although the large price gap between steel and aluminum is beginning to shrink. So while aluminum drop decks are more affordable than ever, you can still expect to pay thousands of dollars more for aluminum or hybrid steel aluminum combos.
Still, it’s important to remember you are offsetting the initial upfront cost on aluminum drop decks in their longer lifespan and greater resale value. These trailer types can retain up to 70 percent of their original value if you are the original owner trying to sell it.
The fact is, as aluminum drop decks continue to boost their market share – from 30 percent today to 40 percent five years from now – investing in them for our fleet isn’t such a bad idea.
Where Smart Trailers Come into Play
We recently looked at the new wave of smart trailers hitting the market. Whether you’re looking at sensor-enabled reefers or multi-compartment trailers with individualized temperature control, could we see such innovation where drop decks and flatbed trailers are concerned?
Certainly, one area where innovation is happening is around smart sensor and smart strapping technology. As flatbed companies continue to innovate, drop decks and other flatbed types are being built with sensors that can communicate with the truck driver should the load shift in an unexpected way.
The same holds for strapping and load bearing technology. Whether a fleet is using chains or straps to secure their cargo, newer drop deck and flatbed variants can use electronic control systems to measure and maintain cargo securement strength. They can also report on whether there are any weaknesses in the system.
The fact is, we may soon see a day where smart drop decks, flatbeds and trailers can nearly manage every aspect of cargo securement and delivery on their own, with as little involvement from the truck driver as possible.
Developing Common Operating Protocols and Preparing for the Future
No matter what happens in the drop deck, flatbed and trailer space, common protocols and OEM alignments will have to happen across the board. Whether we are talking about the materials used in constructing the trailers or the advanced technologies built into them, there’s a lot of work to be done on behalf of manufacturers, fleets and other industry players.
Ensuring these consistencies are met is another way to take care of the “sitting trailer” problem. By fully understanding what is needed, whether it be an aluminum drop deck or a sensor-laden steel hybrid flatbed, by synchronizing the trailer market across the board, fleets will be better able to ensure their trailers are on the road with as much up-time as possible.
Is your fleet preparing for the future? Furthermore, are you evaluating what you may need as shipping requirements change and federal mandates come and go. While something as simple as the kind of drop deck you use may not seem like much right now, these are the types of changes that the fleet of tomorrow must prepare for if they are to be ready to haul tomorrow’s loads.
For more information on trailers, trailer telematics, asset tracking and more, be sure to stop on by the QuickTSI blog on a regular basis. We bring you only the latest and greatest in trucking news and information.