With difficulty. You will have to take the overhead train from Colchester to Liverpool Street Station, then the underground to Victoria Station and then the overhead to Gatwick.
No. You can get a tube train from Heathrow into central London and then an overhead train from London to Luton.
Most people call them aerial photographs. Intelligence officers call them "overhead" because in the spy business, aerial Photography is called "overhead coverage."
Fewer moving valve train parts such as the push rods.
Profit
Train Passengers.
A passenger train
The engineer runs the train.
Chew chew train.
A train that carries goods is called a freight train.
You can't travel to West Thurrock by tube, you will have to take the overhead train.
Each part of a train is called a car.