Passengers ingesting cocaine from a table and a teenage girl threatened with a machete were just two of the complaints made to Irish Rail this year, it has emerged.
Other reports lodged with Irish Rail between January of 2020 and June of this year relate to the Dublin-Cork railway line and involve drunken behaviour and harassment.
One person said two people were ingesting cocaine off the table on the train.
A similar complaint says two passengers had a number of plastic bags and drugs on the table, and they were consuming them openly.
One 19-year-old girl says three teenage boys continuously threatened her and made inappropriate sexual comments.
She claimed one of them said he'd hit her head with a bottle and machete if she didn't talk to him.
It has promoted calls from the National Bus and Rail Union (NBRU) for a dedicated transport police.
NBRU general secretary Dermot O'Leary said: "The assistance of a dedicated transport police would help.
"I think it's only a matter of time before something serious is going to happen, unfortunately - and that's one [thing] I don't want to be true."
Dublin-Cork is the busiest inter-city route and Irish Rail says while these incidents are regretted, 26 complaints over 18 months indicate the vast majority of journeys occur without incident.
A spokesperson for Irish Rail added: “The issues detailed are not representative of the typical experience of customers on our services.
"Anti-social behaviour is a societal issue to which we are not immune, and the complaints illustrate the upset caused to customers by a tiny minority who engage in it, within a range of issues as detailed, most notably relating to alcohol or drug abuse, and Covid-19 measures.
"Each issue which causes a threat to customers or employees is investigated and we liaise with the Gardaí to address instances of anti-social behaviour, including provision of CCTV.”
When asked by Independent.ie if Irish Rail would consider having dedicated transport police, the spokesperson said: “The structure of policing is a matter for the Gardaí, but we have established excellent liaison with Gardaí right along the route, to ensure swift response to such issues, as well as on-board patrols and operations.”