Kolkata: A Metro rake ran from Belgachia till Kavi Subhash on Friday morning with one of its door open, after it failed to close down due to some technical snag.An RPF personnel stood guard at the door to prevent any untoward incident. According to sources in the Metro, the snag developed after a broken portion of a pen cap somehow got stuck in the door channel.The snag came to the notice of the motorman at around 11 am in the morning, after the train reached Belgachia Station. The front door of the first compartment refused to close as the train was about to depart. Also Read – Rain batters Kolkata, cripples normal lifeAn RPF personnel on duty at the platform noticed a plastic object sticking out of the door channel. As he tried to remove the same, it broke with a portion of it coming off in his hands, with the rest still remaining stuck in the door channel.Within a few minutes, the decision was taken by the railway police in coordination with the Metro authorities that the rake should continue to run. An RPF constable stood guard at the door with his hands on either side of the door, as the train continued its journey. There was a change of duty at Chadni Chowk Metro Station and this time, two RPF personnel stood guard at the door till the journey ended at Kavi Subhash. The motorman tried to close the door in between as the train stopped at stations, but failed to do so.”We could have emptied the rake when the snag took place. This could have inconvenienced the passengers. So we decided on keeping the train running after ensuring the security of the passengers. When the train reached Kavi Subhash, it was sidelined to the car shed,” said a spokesperson of Kolkata Metro.The portion of the broken pen cap was removed and after proper testing of the door, it was found to be working perfectly.