The War Machines are robots that appear in the 1966 Doctor Who episode of the same name. After a long absence, the War Machines return fifty years later when they fight against the Surgeon in the story Thunderbolt.
The War Machines are remote controlled robots built like tanks and designed to help the supercomputer WOTAN take over the world. They are mobile-computers controlled by WOTAN and armed with guns and swinging arms attached with heavy-hammer heads and also have the ability to jam guns.
Like tanks, the war machines are also incapable of advanced movement or any great speed, traveling slower than an average walking speed but in Thunderbolt they move much, much quicker, about the speed of a TR-85 tank. Each individual machine is numbered- the Doctor reprogrammed War Machine 9. In their initial appearance, the machines are developed, assembled and tested in secret in a warehouse in London whilst in Thunderbolt they are designed in a warehouse in Bucharest where they are also activated.
In an original draft for Part 2 of Thunderbolt when the War Machines are introduced, War Machine 7 unveils itself and takes a warehouse worker who was watching the Romanian Army delivering British and Russian missiles to be destroyed and pulls the worker to the Palace of the National Military Circle where the worker would be killed and reconstructed by WOTAN.
This draft however was scrapped because it was considered to be underwhelming. In the new draft, an un-named War Machine unveils itself from a crate but instead, it menaces the warehouse worker and under WOTAN's orders kills him before the computer orders it to lie dormant and await further orders.
After the Surgeon and his new companion Amanda Mycroft leave the Army after confessing to being unable to help them solve their problem of vanishing people and seemingly destroyed missiles, War Machine 7 which was the one who killed the warehouse worker is activated by WOTAN and is sent to find the Surgeon and Amanda for unknown purposes.
More War Machines are then activated thanks to WOTAN being forced to put its plans into action early thanks to the Surgeon. At first, the War Machines roam the streets until they come across the Surgeon at which point they go berserk and start attacking Bucharest locals as well as trying to capture the Surgeon...until the Army comes to help him; what happens next is probably one of the most one sided battles the Surgeon has ever faced in his journey across time and space.
But also among the Army are twenty shadowy figures who also attack the War Machines and assist the Surgeon and Amanda in escaping from them. The reason this is one sided is because the War Machines jam all the Army's guns and gun them down...just as the Surgeon and Amanda have escaped from them.
In retaliation to the Surgeon and Amanda escaping from it, WOTAN puts its plans into action immediately and so transmits a signal through the whole of Romania which activates all War Machines in the country which travel around Romania carrying out their orders to destroy all humans; but WOTAN has also sent another signal through Romania which paralyzes the country and even hypnotizes the Surgeon.
After the evil computer has hypnotized the Surgeon and brought him to an Army base where the missiles are, there are War Machines that are shown at the Army base alongside the missiles and all of the people that WOTAN had hypnotized. The War Machines soon engage in a huge war with the Romanian sisterhood who is led by Amanda Mycroft and even come under attack from one of their own kind in the form of War Machine 9 which had been reprogrammed and later destroys WOTAN which brings an end to the War Machines.