ITAG Equipment has always carried a wide selection of drop deck trailers or, as some refer to them, step deck trailers. They are the same, just two different names for the same trailer, depending on where you are or what you usually call the trailer.
We could break the trailer into two categories if we wanted to get a bit more technical. A single drop deck trailer and a double drop deck trailer. A single drop deck trailer typically has about 24 inches of a drop from the top deck to the bottom deck. As one might imagine, a double drop deck trailer has double the drop distance from the top deck to the bottom. Most single drop deck trailers have 10ft top decks and 38ft or 43ft bottom deck space, depending on the length of the trailer. On occasion, you'll see 8 or 11ft top deck lengths.
These trailers come in two sizes. In total length, 48ft or 53ft long are the two most common sizes. Some manufacturers make oddball sizes like a 50 or 51, or 52ft trailer. Doonan usually carries some of these different size drop deck trailers. Rarely but at times, you can find some 45ft drop deck trailers on the market, but most of the time, they come in 48ft or 53ft length size. The standard width across the board is 102inches wide. When measuring the width of a drop deck trailer, you go from the outer side rail or, as some call it, a rub rail to the other outer side. If you measure from the outside of deck space to the opposite outside of deck space, it'll hit right at 96 inches, but that's not how these trailers are measured unless the trailer does not have a side rail. Including the rub rails is where you get the 102inch width measurement. Kingpin settings on these trailers are sometimes set in funky positions. Commonly they measure about 18 inches deep.
Starting from the front of the trailer to the center of the kingpin is how you measure the distance. If you have a short top deck length, this measurement could be significant depending on what kind of semi truck you have and where the fifth wheel is positioned on the tractor truck. If the kingpin setting is too deep and the top deck is short, and your fifth wheel isn't set back far enough or cannot slide back, you could hook up to a trailer that won't work with your 18-wheeler truck. You may have to figure out how to get your fifth wheel to slide back. Even after moving the fifth wheel around, it could throw off your weight distribution and render the semi-truck and trailer combination useless for hired operations without some intensive custom fabrication that could be costly. Drop Deck or Step Deck Trailers are highly versatile as they can be used to carry vehicles, heavy equipment, construction equipment, paving equipment, piping, cars, vans, military vehicles, and more. Drop deck trailers can be outfitted with beaver tail and ramps on the back for ease of loading, and aluminum ramp kits installed on the side of the trailer. The aluminum ramp kits can also double as load levelers to enable the truck driver to use the trailer like a flatbed or flat deck trailer. The low height of the bottom deck on the step deck trailer allows for taller loads to be hauled on the trailer than what can be accomplished on a flatbed.
Trucking can be a game of pounds and inches with a constant need to be able to be as low and light as possible to avoid having to obtain overweight or over height permits which can be costly depending on the distance traveled. Drop deck trailers come standard with two different types of flooring; Wood floor or aluminum flooring. Steel, rubber, or other flooring types can also be installed on drop deck trailers, but wood or aluminum are the two most common. Cross-members are steel or aluminum construction i-beams that run horizontally down the trailer from left to right or right to left, whichever way you choose to look at it. Aluminum cross-members are better for making the trailer lighter and have less corrosion risk than steel cross-members typically carry. There could be a case for durability or strength between the two metal materials. Still, aluminum is widely used across the marketplace, from passenger vehicles to trailers, and has many advantages, from weight to corrosion. ITAG has refurbished and seen many used drop deck trailers over the years, and if we were truckers in another life, we would prefer to have aluminum cross-members on all of our trailers. The main beams on drop deck trailers are made of steel or aluminum. Most all trailer manufacturers make a combination trailer consisting of steel and aluminum. All aluminum trailer manufacturers include Reitnouer, East, Benson, Mac, Fontaine, Doonan, and more.
Steel and wood step deck trailers are the heaviest, and all-aluminum trailers with more aluminum construction tend to be lighter. Double Drop Deck Trailers are in the same family as single drop deck trailers but look a lot like lowboy trailers and are confused as lowboy trailers many times. Double-drop deck trailers can have a stiff neck or a removable neck. Double drop deck trailers will have a loadable top deck and bottom deck. Lowboy trailers do not have loadable top decks. Double drop deck trailers can also be rated by capacities, such as 35 or 40 tons. There are many variations to choose from depending on the application of the trailer. Should you have any questions on what you need for what you are hauling or using the trailer for, please let us know, and we will help you as much as we can.
Frequently Asked Questions (FAQ's)
Who makes drop deck trailers?
Several manufacturers, including Fontaine, Wabash, Reitnouer, Mac, Doonan, East, and more!
Are step deck and drop deck trailers the same?
Yes, the same type of trailer, with two different words commonly used interchangeably. A step deck or drop deck trailer is a commercial semi-trailer if it is rated with a GVWR that meets commercial equipment standards. Sometimes you will find lighter-duty trailers built like a drop deck or step deck trailer but not rated for heavy loads. It is essential to look at the vin tag on the trailer before you purchase to ensure it will work for your hauling needs.
How much weight can a drop deck semi-trailer carry?
A loaded question with more than one answer! 80,000 lbs is the standard truck/trailer/cargo weight allowed before overweight permits, and additional axles on your truck or trailer are required. The distribution of the weight has to be correct as well. If you have a heavy truck and trailer, you won't be able to put as much cargo weight on the trailer. The lighter your semi-truck and trailer weighs, the more cargo you can put on the trailer pending the trailer being rated for that much weight, and your weight is distributed correctly. Many truckers buy all aluminum trailers as a strategy to get their combined truck and trailer weight down so they can haul more cargo weight. Cargo weight can determine what type of truck and trailer you'll need to purchase. Generally, 40-50 thousand pounds is what you'll be able to carry on a commercially rated drop deck trailer depending on the combined weight of your truck and trailer. For example, if your semi-truck weighs 20,000 lbs and your trailer weighs 14,000 pounds, you are left with 46,000 lbs you can haul on the trailer to be at or under the 80,000 lb gross weight standard.
How high is a drop deck trailer?
Drop deck or step deck trailer height can vary by manufacturer and size of tires on the trailer. Most drop deck trailer heights will measure in at 40 inches. You can find some drop deck trailers with ride heights as low as 33-37inches. Some truckers buy drop deck trailers with 17.5 tires to try and get the trailer height as low as possible so they can haul a taller load. 17.5 tire trailers come with the height advantage but do have some disadvantages. If you aren't familiar with running a 17.5-tire trailer, it could cost you a small fortune in tire bills. The best practices we recommend when purchasing 17.5 tire trailers are buying the 245/70R17.5 size, the best tire brand you can afford, and keep your speed as close to 60mph as possible. If you find yourself in the south with scorching 100-degree heat, we would recommend trying to schedule your rest periods during the hottest part of the day. The temperature of the roads your tires are running on will be much higher than the air temperature. Smaller tires have more revolutions per minute, get hot quicker, and are more prone to blowouts. It would also be wise to know the weight rating of your tires. Your trailer may be rated for the heavyweight, but if your tires are not, you will be on the side of the road with blowout after blowout. As with all trailers, the better you take care of it, the longer it'll last!