Marathon carriage
A marathon carriage is a modern metal carriage that is used for driving competitions, especially combined driving. It is named after the cross-country phase of a combined driving event which, though inaccurate, became known as the "marathon" phase. The carriage is designed for safety and carries a driver plus one or two assistants, called grooms. Drivers direct the horses while grooms counterbalance the carriage on tight turns, and are available for assistance with the horses in case of an overturn or collision, or equipment malfunction.
In the marathon phase of combined driving, competitors navigate a series of obstacles designed to test the agility, speed, and control of the horses and carriages. These obstacles often include water crossings, tight turns around posts, steep inclines, and narrow passages. Each obstacle is constructed to challenge the driver's precision, the horses' obedience, and the groom's ability to counterbalance the carriage. Clearances are tight and posts are often placed to require sharp tight turns. The course layout demands quick decision-making, making the design features of the marathon carriage—such as cambered wheels, bumper bars, and low centers of gravity—essential for safe and successful maneuvering.
Design
A marathon carriage is made of steel or aluminum, with non-slip surfaces and wide fenders because it may be travelling through water and mud during competition. They are constructed for safety with a low center of gravity, and a very small turning radius, both of which help reduce the chance of overturning. A low platform for the groom at the rear allows a crouching groom to further lower the center of gravity. They usually include hydraulic disc brakes, suspension, and plenty of handholds for the grooms. Many of these vehicles are made with adjustable-width axles to conform with requirements for minimum track widths in certain competitions.Shafts for single-horse carriages are shortened to terminate at the harness saddle instead of reaching the horse's point of shoulder. The driver's seat is usually raised with high sides to keep the driver in position. Many teams have the groom holding a belt around the driver's hips to keep the driver secure during maneuvers, but if the carriage overturns, the driver will not be pinned as he might with a locked in seat belt.
Wheels have metal spokes, welded at the hub, which can tolerate sideways forces. Hubs are constructed flat; traditional wooden wheels have protruding hubs which have caused difficulties in the marathon obstacles. Some vehicles are designed with cambered wheels to reduce sideways sliding. Marathon vehicles are constructed with horizontal guard rails to deflect the carriage from posts and small trees and keep from getting caught on them. A bowed rail across the front protects the front wheels, and rails running down each side over the wheels keeps from getting a post caught between the front and rear wheels when turning sharply around a post. The open back design makes for easier, quicker and safer entry and exit of a groom, who previously entered from the side between the wheels. Looking quite different from traditional carriages, they acquired the nickname "battle wagons".
Since a marathon carriage is built with the front axle pivoting on a turntable, the front wheels can rotate until one wheel is fully under the body of the carriage. During such tight turns, the carriage operates like a three-wheeled vehicle, and the entire carriage can easily tip over if not careful, risking severe injury to the occupants.