The gate arm falls Tuesday on the railway police, who have provided security on trains trundling up and down the country for 72 years.
Also known as "train marshals", the onboard patrol was introduced after the modern Thai railway system came into service during the reign of King Chulalongkorn.
The withdrawal is prompted by the latest restructuring of the Royal Thai Police (RTP), and officers will be redeployed in other departments within the force under the National Police Act 2022.
Starting out as a "rail track patrol squad", officers were later transferred to work on trains to combat rising onboard crimes.
In 2005, the unit was renamed the Railway Police Division (RPD), responsible for taking care of passenger safety and for patrolling various areas along the tracks.
The RPD officers were based in several stations in and outside of Bangkok nearby their respective train stations, such as Noppawong, Makkasan, Hua Hin, Hat Yai and Nong Khai railway stations.
The unit worked extensively with the State Railway of Thailand (SRT) in keeping an eye out for and tackling criminal activities. Its duty to maintain peace and order also extended to areas in and around train stations.
The job of providing safety at terminals will now be filled by local police, while the authority to search belongings onboard trains will be handed to SRT staff.
A celebration was held recently to pay tribute to the RPD's service and dedication. SRT governor Nirut Maneephan, who presided over the event, conveyed his thanks to the officers who have kept train journeys safe for all these years.