Selecting appropriate construction materials for trailers.
Choosing a horse trailer can be confusing, especially when deciding what kind is best for you and your horse. Horse owners have very definite ideas about construction materials. Visit any equine internet discussion board and you will see how heated the debates can become on the topic of construction.
It’s interesting to note that there are no government regulations concerning the safety of horses in trailers although USDOT (United States Department of Transportation) has regulations about length, width, brakes, lights and licensing. As long as the trailer meets these requirements, it can be built to any design and with any material. Because of this, trailer safety and design, or lack of same, is often determined by the marketplace. Most manufacturers build what they think the customer wants. So the more demanding and informed the public is, the better and safer the trailers will be.
When it comes to construction materials, it’s important to know the benefits and limitations of each. There are three types of construction: all-aluminum structure, all steel structure, and composite built or hybrids.
A Bit About Aluminum
In the beginning, horse trailers were built of steel and were just a “tool” to get a horse from one place to another. Not much consideration was given to the health or well-being of the horse. Most trailers were small, and designed more for the horse owner than the horse. Some examples would be a manger style trailer – claustrophobic for the horse but beneficial to the owner for saddle storage under the head area. Some only had one axle and many had brakes on only one axle. As horse owners got more sophisticated and willing to spend more money for trailers, designs/features began to improve.
In the early days, rust was a big problem and very obvious to the trailer-buying market. Some trailers would actually rust before they left the sales lot. In the 1980s, some trailer manufacturers decided that an all-aluminum trailer would eliminate the rust problem. When the first all-aluminum trailers hit the market, they had some real problems. Strength was an issue and they had some structure failures. But they kept at it because the buyers were certain about two things: steel rusted and aluminum didn’t. So the manufacturers continued to improve these trailers. By the 1990s, economic times were good and it became a status symbol to have an all-aluminum trailer. That’s what people wanted to buy, so that’s what many horse trailer manufacturers built.
Aluminum may not rust, but it corrodes. Alkaline in the urine and manure can completely destroy a floor in about eight years if it is not washed regularly. And although aluminum is lighter than steel, it’s only one-third its strength, pound for pound. To make it equally strong it needs to be three times thicker, which eliminates the idea of it being lighter.
Most quality all-aluminum trailers have very thick frames that are quite strong. But since aluminum is so expensive, many manufacturers use lighter and weaker construction for the interior dividers, butt and breast bars, roof and siding. This makes the trailer more price-friendly and also reduces weight. However, those parts are more likely to break when a horse acts up or the trailer is in an accident. When considering an all-aluminum trailer, better quality usually means a higher price, so beware of an inexpensive one.
When aluminum becomes torn or bent, it can never be restored to its original strength. Repair is expensive and not all body shops have welders that are qualified to weld aluminum.
Aluminum is also a heat conductor, which is why it makes good cookware. Horse trailers with aluminum floors are hotter than those with wood floors.
The Strength of Steel
In our opinion, aluminum is a good choice for nonstructural trailer parts, such as in a dual wall construction where prepainted aluminum skin is used as an outer skin. But we prefer steel for the main structural parts. In fact, all-aluminum trailers have steel couplers and the axles are attached to a steel frame, because the aluminum used for horse trailers is not strong enough for these important parts.
Imagine two pipes that are the same thickness. One is steel and one is aluminum. If each pipe was struck with the same force, and if that force was strong enough to break the aluminum pipe, it would only bend the steel pipe. In order for the aluminum pipe to withstand that force equally, it must be three times as thick. Exchange that first aluminum pipe for one that is three times thicker and it will be almost equal in weight to the thinner steel pipe. Steel has always been the strongest building material for the price.
If we go back to the beginning when steel horse trailers rusted away, we learn that the steel was not coated and of poor quality. Steel technology has vastly improved over the years, all but eliminating rust. Many manufacturers are now using galvanized or powder-coated (baked-on paint) steel. Even stainless steel is available if you are willing to pay for it.
The benefit of steel’s strength becomes obvious when a horse trailer is in an accident. If a trailer is struck or overturned, you want the frame to bear the brunt as well as possible, and you want the interior dividers to hold up too. Steel is more likely to bend instead of break, eliminating the sharp edges that often occur with aluminum. It’s also cheaper and easier to have a steel trailer repaired. When properly cared for, a steel trailer can last for many years.
Wood has been used for trailer floors for many years. There are different qualities of wood floor and many have lifetime warranties. Wood does not conduct heat like aluminum, and we prefer it for the comfort of the horse. When a wood floor is covered with mats and kept clean, it should last as long as the trailer. If it does need repair, it’s an easy, inexpensive project.
Rumber is a flooring product that has recently come on the market. It’s a combination of recycled tires and plastic. The benefit is that it can be used without mats. We like to use a product before we can recommend it, so Neva hauled her 1,400-pound Holsteiner in a trailer with a Rumber floor. His shoes scraped up lots of little particles and we have had customers who tell us that it can wear smooth with a lot of pawing. It is also flexible and has some “give” under the weight of a horse. Extra supports have to be used to compensate for this.
Making an Informed Purchase
Some trailer manufacturers use all these materials to their best advantage to build a strong trailer that is the same weight as an all-aluminum one. But construction materials alone can’t be the ultimate deciding factor when purchasing a trailer. Standard safety features, ventilation, size, style, etc. are all important factors. Also, the quality of the manufacturing process and of each material is different with each trailer brand. When you are purchasing a trailer, look for features that are horse-friendly and will hold up to the biggest and strongest horse you will be hauling. As a trailer-buying customer, you will be influencing the marketplace with your purchase. Making an informed and intelligent decision means you’re doing your part to help create a better and safer horse trailer for all.
Fiberglass is a great material for nonstructural trailer parts. Usually used for roofs and fenders, it is light in weight, doesn’t conduct heat and is easily repaired. If it tears, it isn’t sharp and usually won’t cut a horse. It is not strong enough to be used as a roof on its own – it’s best when a frame is molded into it to provide the strength a roof needs if the trailer rolls.
It should also be noted that an insulated trailer (with Styrofoam or another type of insulation material) will be cooler and quieter than a trailer that is uninsulated.
Neva Kittrell Scheve and her husband Tom are the authors of the nationally recognized textbook The Complete Guide to Buying, Maintaining, and Servicing a Horse Trailer. Neva also has two other horse trailer books to her credit, including Equine Emergencies On The Road with Jim Hamilton, DVM. Besides being authors, clinicians and writers of numerous published articles on horse trailer safety, Tom and Neva have designed and developed the EquiSpirit and EquiBreeze line of horse trailers manufactured in Kinston, North Carolina. Visit equispirit.com or email firstname.lastname@example.org.