Police will be using mobile metal detectors at stations around this year's Notting Hill Carnival in an attempt to crackdown on knife crime.
Mobile metal detectors will be used to detect knives
The metal detection arches will be moved frequently on both days of the carnival - on 26 and 27 August.
There will also be specially trained sniffer dogs to find drugs and weapons and 650 officers on trains and at 20 stations around the area.
The scheme is being led by British Transport Police.
More than half of carnival-goers are expected to travel by train or Tube.
Asst Ch Con Paul Crowther said: "Officers will be highly visible on the rail network throughout the carnival weekend helping people get there and back safely.
"Carnival has a fantastic atmosphere and we see ourselves as key players in the overall event to allow people to enjoy all it has to offer.
"While we're certainly not there to spoil the fun, we want people to have a safe time as well as a good time."
He said the British Transport Police want anyone who has other intentions to know exactly what they can expect, especially if they try to bring weapons to the carnival.
About 100,000 people are expected to travel on the rail network for the carnival's family day on Sunday, 26 August and 300,000 people on Bank Holiday Monday, 27 August.