The New Measurement Train (NMT), also known as the Flying Banana, is a specialised train which operates in the United Kingdom to assess the condition of track so that engineers can determine where to work. It is a specially converted High Speed Train, consisting of two Class 43 power cars and five or six Mark 3 carriages.

It can check the condition of most main lines and some secondary routes operating on a 4 weekly cycle. This cycle replaced its original 13-week cycle after the introduction of the Plain Line Pattern Recognition (PLPR) Design Patrolling Program. The train is permitted to travel across any part of the network where HSTs are permitted, as well as High Speed 1.