No. Triple trailers are not allowed on any Washington roadways.
It's an endorsement to pull double or triple trailers.
A handful of states permit 57' trailers. However, most states only permit trailers up to 53' in length.
Yes you can. You can pull doubles and triples. You can pull two 48 trailers and two 53 foot trailers. You can pull three 48s, but you cannot pull three 53 foot trailers.
Yes
No
It seems like you're referring to endorsements. "T" is the endorsement to pull double and triple trailers. "X" is a combination of two endorsements - Hazardous materials, and tanker.
Arizona, Kansas, Louisiana, New Mexico, Texas, and Wyoming will allow you to pull 57 foot trailers. Texas and Louisiana will allow you to pull 59-foot trailers that were licensed prior to December 1, 1982. All states will allow you to pull 53-foot trailers. Although the technically correct answer is 59 feet, the fact that the only run you can actually make in a 59 is from Texas to Louisiana and the very limited range of states a 57 can be used in means the longest practical trailer is 53 feet long.
Horse trailers were invented around 1960. Because most of the vehicles didn't have enough power to pull the trailers, most people didn't have them.
Yes
Cattle trailers are used to securely store and transport cattle by ranchers. These trailers can range in size from accomodating one or two cows to several dozen. The trailers are attached to an SUV or truck to pull them.
There are several options that you can choose from. First, there are bumper pull or gooseneck. Of those, you can get steel, aluminum or a mixture of both. Then you can have what is known as a stock trailer or a horse trailer. Another option is whether you get a straight load or a slant load. Lastly, it may have a dressing room or full living quarters. So, it can vary greatly depending which options you choose to pursue.