Trakehner
These fences consist of a rail over a ditch. The ditch can be frightening for the horse, and so this type of jump is a test of bravery. Trakehners are first seen at training level (United States), and at the higher levels they can be quite large. A Faux (False) Trakehner is a mobile cross-country jump designed to look like a trakehner by using heavy posts or poles on the ground to simulate the front and back edges of the ditch.
Trakehners were originally fencelines that were built in drainage ditches. The Trakehnen area of East Prussia, originally wetlands, was drained by the Prussian kings in the 17th and 18th centuries, before a horse breeding program was begun. The Main Stud Trakehnen, which produced the Trakehner breed of horse, was established on the land in 1732. The large drainage ditches, with fencelines in the bottom of them, were later used as a test for the 3-year-olds for suitability for breeding and war mounts. Due to the build of the fence, the take-off spot for the horse was on the downside of the ditch, and the landing was on the upside. However, the old-style trakehner jump is not seen today, mainly because the landing was on an uphill grade, which was very punishing to the horses, even when the horse took off well. The ditch is now revetted, and the fence does not have an uphill landing.
In 1973, Rachael Bayliss and her horse, Gurgle the Greek, "cleared" a trakehner at the Badminton Horse Trials by going under it. The rules were changed after this incident, requiring the horse not only to go between the flags but also to pass over the log.
Read more about this topic: Horse Jumping Obstacles