Train (military)

In military contexts, a train is the logistical transport elements accompanying a military force. Often called a supply train or baggage train, it has the job of providing materiel for their associated combat forces when in the field. When focused on provision of field artillery and its ammunition, it may be termed an artillery train. For sieges, the addition of siege engines to an artillery train was called a siege train. These military terms predate and do not imply a railway train, though railways are often employed for modern logistics and can include armoured trains.

For armies, this historically usually referred to forces employing wagons, horses, mules, oxen, camels, or even elephants. These can still be useful where difficult weather or topography limit use of railways, trucks, sealift, or airlift.

The United States Department of Defense Dictionary of Military and Associated Terms defined the term "train" as:

A service force or group of service elements that provides logistic support, e.g., an organization of naval auxiliary ships or merchant ships or merchant ships attached to a fleet for this purpose; similarly, the vehicles and operating personnel that furnish supply, evacuation, and maintenance services to a land unit.

In the Ancient Macedonian army, restrictions were placed on the size and composition of the baggage train by Philip II of Macedon and his son Alexander the Great. Carts were generally forbidden – with the exception of carrying essential items such as siege engines, tents, plunder or acting as ambulances – because they were considered to impede the army's speed and mobility. Throat-and-girth harnesses of the period would cause choking if too much weight was being pulled, carts were liable to break down, and they could not travel in rough or hilly terrain. Instead, supplies were carried by soldiers, the servants accompanying them, and pack animals. Horses and mules were the primary pack animal in the Macedonian army, each capable of carrying 200 lb (90 kg) (excluding the weight of the pack saddle); after the conquest of Egypt these were supplemented by the use of camels, which could carry 300 lb (140 kg). Neither oxen or ox carts were used as they were slower, had less endurance, and their hooves ill-suited for long distances compared to horses and mules.

The individual Roman legionary carried his possessions and tools on a forked pole across his shoulder when on the march. However tents, equipment and bulk supplies were transported by separate train detachments composed of mules and wagons under the control of camp servants.

In common with most European armies of this period the Russian army relied primarily on the short-term employment of civilian contract drivers to provide transport and supply services. However following reforms in 1760, organised siege train "parks" were raised to furnish wagons and other support for the heavy guns and mortars of siege artillery.

The Noble train of artillery, also known as the Knox Expedition, has been highlighted as one of the incredible feats of logistics of the American Revolutionary War. From November 17, 1775, to January 25, 1776, Colonel Henry Knox transported 60 tons of artillery and other ordnance from Fort Ticonderoga to the Siege of Boston, a distance of approximately 300 miles (480 km). The arrival of these cannon helped end the siege in an American victory.