Alleged saboteurs believed to be behind the recent spate of train torchings all used the same method: they pretended to be commuters before setting the carriage alight as the train arrived in the station.This is according to mayoral committee member for transport and urban development Brett Herron, who said he didn't make the allegation of sabotage lightly."The alternative is these are random opportunistic crimes for no purpose. But when you see trains being burnt three or four times a week, every week in the same manner, it suggests to me that there is someone, some organisation or some force that is seeking to destroy our commuter rail system," he told News24 on Monday."These fires are being set apparently shortly before trains arrive in stations by someone who is on the train. They ignite a fire and exit as the train arrives at the station. It's just too well-planned, too consistent and too frequent for it to be random."READ: Cape Town train attacks by numbers In the last three months, four trains were apparently hit by arsonists. Most recently, two carriages were set alight at Cape Town station on Saturday.On Thursday, five carriages and overhead power cables were damaged when a train was torched at Retreat station.R50m damage in one weekLast Saturday, two coaches were burnt at Cape Town station and the platform's cabling was damaged. In May, a commuter was killed in a fire near Ottery station while another suffered severe burn wounds.Last week alone – barring this past Saturday's incident – the damage caused to trains and infrastructure came to a total of more than R50m."The motive and who benefits is the R50m question. Why would there be this campaign to destroy the trains?" Herron asked.WATCH: Train carriages on fire in Cape Town Transport Minister Blade Nzimande on Friday visited Passenger Rail Agency of South Africa's (Prasa) Paarden Eiland depot where he viewed damage to the state-owned enterprise's infrastructure caused during the various arson attacks.Herron, who accompanied the minister as he met with authorities, said Nzimande asked the provincial police commissioner as well as his heads of detectives and Crime Intelligence what could be behind the arson attacks.149 carriages lost to fleet since 2015"Crime Intelligence was not able to provide us with information. Work has to be done in the intelligence space to understand what could be driving this."According to Metrorail, six train fires have been recorded this year. Since May 2015, the province's train fleet has lost 149 carriages.READ: Three railway coaches set alight at a Cape Town train stationHerron said that last year parked trains were targeted overnight – despite supposed strict security. "That was a different modus operandi. The current pattern is that it seems to be someone who is on board, who has some flammable material that can ignite a fire and disembarks the train. So the train is arriving on the station already partially alight," he said.During the minister's visit, Prasa's head of security explained that the seats in the older trains are made of highly flammable material, Herron said. As the gutted coaches are replaced, more fire-resistant material will be used.Aging infrastructure, cable theft, signalling interference and operational challenges already have an undesirable impact on the rail service, Herron said.Train trip"Cape Town is already running at a fraction of the train capacity. We're operating with between 45 and 50 train sets – there's supposed to be a minimum of 88."On the central line, which goes through Khayelitsha and other communities which really rely on the service, about 30 trains should be operating. They have eight."Herron last year took a trip from Nolungile train station to assess the crisis.His train was an hour late and he was advised by a commuter to jump on the top of the carriage as passengers had already been hanging out of the doors and windows.He waited for the next train instead. A person who had taken his chance atop the coach that morning was electrocuted and died."The rail system – with a full set of trains operating at a good frequency – could provide 1.4 million passenger trips a day. It is currently on 400 000. If we could get more people back onto trains because they are safe, efficient, regular and reliable, we would address traffic congestion which is costing our city economy R2.8bn a year."Rail system collapse could be 'bigger' than droughtHerron in February called a rail crisis summit attended by City of Cape Town officials, provincial government and Prasa to discuss the securing of infrastructure and improving passenger safety.A joint decision was made to establish a law enforcement unit to operate on the rail system. Each entity contributed R16m to fund the employment of about 100 dedicated law enforcement officers.They will form part of the City's policing unit and will focus 40% on infrastructure protection and 60% on passenger safety. Herron confirmed the officers were in the process of being recruited and were expected to be trained and ready for deployment by the end of September.A rail task team was also established at the summit to manage the implementation of the new unit and to monitor the rebuilding of Metrorail's train capacity.Nzimande on Friday also requested seats for his department and the police at the table. He asked that a place be made in future for the National Prosecuting Authority as well. Herron welcomed the national department's inclusion in the project."This is beyond politics. This is about saving our city. If we thought the [drought] was going to be a disaster for Cape Town, the collapse of the rail system would be bigger."