Recently there has been a resurgence in the comparison of structural materials used in horse trailers. A common theme has been that aluminum is not an appropriate material. In my opinion, this has been propagated by some steel trailer manufacturers, in attempts to sell their own products. Their "professionals" have made statements that are now being repeated by the public as being de facto. I disagree as shown by the following statements I made a few years ago.

There have been ongoing comparisons and discussions about the suitability and supposed superiorities of steel vs aluminum constructions. There are proponents of each, and has been proven over time, both work well. If anyone has read my past postings about the subject, you should know that I am not anti either material. My main objection is the misinformation and false statements being spread by steel trailer manufacturers, that can bias an unwitting purchaser into a trailer that may not be suitable for his usage.

The following statements are taken from Internet postings of two builders of steel trailers, and some declarations made by one of the owners.

"Due to the brittle nature of aluminum, it will tear or splinter and doesn't provide the safety needed for long term durability". "Many horse owners think all aluminum horse trailers are the best for weight savings.  Aluminum is a light weight metal, but is also easy to bend and break. Our Z-Frame® is a light weight material like aluminum, but does not bend nor break compared to aluminum horse trailers with aluminum frames". "Aluminum trailers tend to be brittle in nature". "Keep your horses safe from serious lacerations and injury that often happens with aluminum structure, dividers, butt/breast bars, which crush and tear on impact". "Whereas all-aluminum construction is no longer acceptable because of sheering, cracking, heat, and repair issues". "Weaker aluminum dividers will rip and shear causing lacerations when impacted beyond their capacity". "Aluminum can easily bend, which is neither safe or comfortable for your horses".

Let's address those issues. Yes aluminum bends and also has some plasticity which allows it to stretch. It doesn't mean the metal will fail. Apparently the authors of those statements have never flown, or if they have, they are members of the fearsome fliers club and have never looked outside the windows. If they did, they would have seen aluminum wings that constantly flex. Have they broken off? There are DC-3s flying today that are 3/4's of a century old; our best bomber is now almost 60 years old, and is scheduled to remain in service for a few more decades. Here's a video of a wing being tested to failure; you can see how far it bent before breaking.

http://www.youtube.com/watch?v=Ai2HmvAXcU0

The authors also are unfamiliar with recreational boating, in which countless aluminum boats have been manufactured. Many generations of boaters have used the lightweight, single skin, stamped aluminum hulls of riveted construction. The hulls flex with every wave, occupants moving within, beachings on the shore and trailering. They are maintenance free, reliable and exist in a hostile environment.

The Coast Guard uses vessels in search and rescue. This is video of a 47' MLB. It was designed to be operational in 60 knot winds and seas of 20'. Hitting a 20' wave has been likened to slamming into a bridge abutment with your car at speed. Dropping off the crest of a 20' wave into the trough, generates an impact of 3 Gs. These boats are designed to survive a knock down and be self righting in less than 15 seconds. The crew uses suspension seats and body harnesses to survive the impacts without injuries. All the boat's systems are designed to be operational even while inverted. The construction of these boats? Aluminum. Method of construction? Welding. Operational environment? Salt water. Life span? Decades

http://www.youtube.com/watch?v=OMxZSlF-R20&feature=related

Boating and aircraft constructions have one thing in common. They depend on the lightweight structural integrity of the aluminum to provide a safe passage. If a component fails, it may result in a mortality. If a horse trailer fails, the owner pulls to the side of the road and calls US Rider. If aluminum were brittle and constantly broke, our entire transportation system would immediately stop. This includes trains, subways, buses, shipping, aircraft, trucking and even the space shuttles.

 "The acid from the horse’s urine will cause an aluminum floor to rust". "Horse urine and aluminum do not mix well with time".  "Horse urine is extremely acidic and when you pour acid on aluminum, it will oxidize and cause corrosion to the point your horses can fall thru". This is a bit melodramatic and would take many years of neglect to accomplish. Aluminum floors have routinely withstanded years of minimal maintenance before any corrosion control and acid washings were necessary. I have never heard of any horse falling through a properly maintained aluminum floor.

"We use only the finest finished metals with T-6 aircraft quality with exclusive proprietary extrusions for superior strength and durability in our aluminum frame trailers."  T-6 is NOT an aircraft metal. In fact it is not any metal at all. It is a designation for a 3/4 hard, heat treating process.

"there is roughly a 1 to 1 weight ratio of steel vs alum, given similar strength." "there is no significant weight advantage in the most trusted, all aluminum, manufacturers". "It takes three times as much aluminum to match the strength of steel". The manufacturers of airplanes, boats, the trucking industry and automobiles would all disagree with those statements. One example; GM has as much knowledge as any manufacturer in the world, about high strength steels and hydro formed frames. Yet when they wanted to improve the performance of their fastest car, they switched to an aluminum frame to reduce the weight, and provide the additional strength necessary for the larger HP motor and higher speed capabilities. "Chevrolet gave the Z-7 an aluminum body structure whilst shaving off 99 pounds from a Corvette Coupe" 

http://www.sae.org/mags/aei/11744/ 

Many manufacturers of high performance automobiles have used aluminum construction of their components for many years. Almost all of the world's major manufacturers are constantly changing to aluminum components for a weight savings and increased strength. One only has to look at the many  decade's old horse trailers still in service, to realise that their survival is dependant on their aluminum construction materials.

Steel trailers certainly have their place, and so does aluminum. Each has benefits which will appeal to particular owners. Promoting one by flaming the other is a waste full time.