I don't know a lot about the technical side of things, but a good trailer to me is one that is well constructed. It is made with the safety of horse and horse person in mind. It is also user-friendly and constructed from quality materials. The corners are square and welds are strong and clean. It has edges that are not sharp where a person or a horse could cut themselves. It has the appropriate axles for the weight of the trailer and cargo. It should also be built to last.

I was at the KILE Show in Harrisburg, PA this weekend and was told by a trailer dealer that there are no quality trailers out there, all manufacturerers have huge problems. I told him I had to disagree. I have had one trailer out of the five I have owned that had a water leak in the neck and have never had any other problems except for ones requiring regular maintenence.

Different people purchasing the same trailer will have different criteria as to what is the best trailer. I've seen people buy a trailer based only on the interior appointments of the LQ, and not even look at the stalls. My ideas are simple: I want a well built horse trailer first, and a LQ secondly; it is after all, a horse trailer. Both can be modest in appearance, but both have to be reliable and functional.

A well built trailer is dependent on several things: materials, design, craftmanship and engineering. Materials are a major factor in building a good trailer. There are many types of aluminum, not all are the best for trailer applications. In addition to the many types of aluminum, there are treatments for each which can enhance the strengths of the various materials. The better materials cost more, and not all trailers are built using them.

The proper design of a trailer, will enhance the liveability of both inhabitants, humans and the livestock. Easy to use latches, adequate stall sizes, proper ventilation and lighting are only a few of many criteria necessary for a safe and comfortable trip.

Craftsmanship differentiates the quality of trailers, whether it is seen or hidden. The skills of the builders, will help determine the longevity of the trailer. If the construction is hurried and shoddy, your bargan may not be so in a few years.

Engineering is the crux of the build. It will determine the type of materials, their placements, their stresses and ability to handle loads for long term durability. This is where many trailers fail. In an effort to save money, manufacturers will use lighter, cheaper materials in spacings that can cause a failure when the trailer is used hard. Better trailers use additional framing near the rear bulkhead opening, with gussets added to the major joints. Instead of welded butt joints, they are mitered, adding additional strength to the joints.

Some builders use axles and tires that barely meet the weights they are used to carry. There is no reserve capacity. This results in bent axles and blow outs. Better trailers will add a third axle to a long heavy trailer when necessary, instead of having too little axle support.

Here are some specifics: Smooth skin siding is usually .040", and held on by tape. Extruded siding is usually .125" and is welded to each wall stud. You can guess which is more durable. Today, most of the skin metal has tape between the wall studs and the siding. A less expensivelly built trailer will only have the tape. A better built trailer will have additional rivets around the circumference of the panel, to hold and locate the metal. The difference is noticeable after a few years, when the edges start to lift on the unrivited panels. The difference in wall stud spacing will effect the overall rigidity of the wall. Some builders space over two feet, other better ones will be less. Most builders use 6061 aluminum for framing; only a few use t-6 heat treated materials. There have been previous postings, where people wondered why the framework of one trailer was easier to drill into than another. Heat treatments cost more and greatly enhance the strength of the metal.

There are several ways to build a floor. One is to apply individual planks over a framework. The thickness of the planking on better trailers will be .125", heat treated to a T-6 and made of 5xxx series aluminum for better corrosion resistance. The better spacing of the floor joists will be a foot or so or less, with a wide web on the top. Each plank will be individually welded to each joist. Some builders use a continuous sheet flooring, and the joists will have to be closer together to support it without oil canning. 

LQ interiors are another matter, and have little to do with the reliability and structural integrity of the trailer. It would take many hours of typing to enumerate all the differences in a well built trailer. There are manufactures that have good reputations and have sold many trailers for many years. Their owners constantly praise their purchases and have kept their trailers for several years; they are the ones to emulate.