A top-and-tail

railway Rail transport (also known as train transport) is a means of transport that transfers passengers and goods on wheeled vehicles running on rails, which are incorporated in tracks. In contrast to road transport, where the vehicles run on a pre ...

train In rail transport, a train (from Old French , from Latin , "to pull, to draw") is a series of connected vehicles that run along a railway track and Passenger train, transport people or Rail freight transport, freight. Trains are typically pul ...

has

locomotive A locomotive or engine is a rail transport vehicle that provides the Power (physics), motive power for a train. If a locomotive is capable of carrying a payload, it is usually rather referred to as a multiple unit, Motor coach (rail), motor ...

s at both ends, for ease of changing direction, especially where the terminal station has no

run-round loop A headshunt (or escape track in the United States) is a short length of track provided to release locomotives at terminal platforms, or to allow shunting to take place clear of main lines. Terminal headshunt A 'terminal headshunt' is a short l ...

. This is a British term. It is normal for only the leading locomotive to power the train when in top-and-tail mode. It is properly distinct from a push-pull train, which has a locomotive at one end and a control cab at the other end. Trains going up

zig zag A zigzag is a pattern made up of small corners at variable angles, though constant within the zigzag, tracing a path between two parallel lines; it can be described as both jagged and fairly regular. In geometry, this pattern is described as a ...

s of the

Khyber Pass The Khyber Pass (خیبر درہ) is a mountain pass in the Khyber Pakhtunkhwa province of Pakistan, on the border with the Nangarhar Province of Afghanistan. It connects the town of Landi Kotal to the Valley of Peshawar at Jamrud by traversing pa ...

are top-and-tailed, although

Pakistan Railways Pakistan Railways ( ur, ) is the national, state-owned railway company of Pakistan. Founded in 1861 and headquartered in Lahore, it owns of track across Pakistan, stretching from Torkham to Karachi, offering both freight and passenger servi ...

calls this by a different term. In

Japan Japan ( ja, 日本, or , and formally , ''Nihonkoku'') is an island country in East Asia. It is situated in the northwest Pacific Ocean, and is bordered on the west by the Sea of Japan, while extending from the Sea of Okhotsk in the north ...

, the term " push-pull" is confusingly used to describe trains top-and-tailed with a locomotive at either end. (True push-pull operation with a locomotive at one end is not seen on Japanese mainline railways.)

Australia

In New South Wales the XPT is a train with a light weight locomotive at either end. It is based on the British HST. The locomotive at the front operates at full traction power, while the locomotive at the rear operates at half power, the other half powering lighting and air conditioning, etc. This power arrangement is needed to cater with steep 1 in 40 (2,5%, or 25

‰ Per mille (from Latin , "in each thousand") is an expression that means parts per thousand. Other recognised spellings include per mil, per mill, permil, permill, or permille. The associated sign is written , which looks like a percent si ...

) and 1 in 33 (3%, or 30‰)

gradients In vector calculus, the gradient of a scalar-valued differentiable function of several variables is the vector field (or vector-valued function) \nabla f whose value at a point p is the "direction and rate of fastest increase". If the grad ...

. Occasionally a short XPT train operates with only one engine and fewer carriages, in which case the whole train must be turned on a

triangle A triangle is a polygon with three Edge (geometry), edges and three Vertex (geometry), vertices. It is one of the basic shapes in geometry. A triangle with vertices ''A'', ''B'', and ''C'' is denoted \triangle ABC. In Euclidean geometry, an ...

such as at

Dubbo Dubbo () is a city in the Orana Region of New South Wales, Australia. It is the largest population centre in the Orana region, with a population of 43,516 at June 2021. The city is located at the intersection of the Newell, Mitchell, and Gol ...

. Top and tail operation is also used for ballast trains which have to move up and down a line undergoing track maintenance. It is safer to drive these trains from the front when operating in "reverse".

References

Rail transport operations {{Rail-transport-stub