Commuters frustrated by severe disruptions on the trains have taken their anger out on the gates of a station in Hertfordshire, kicking and pushing through them after they were closed to prevent overcrowding.

On Thursday passengers at St Albans were turned away from the platforms following a disruption to East Midlands and Thameslink trains during the morning rush-hour due to a six-mile signalling failure at Luton that caused delays and cancellations across the network.

Since timetabling changes were introduced last month – which saw Britain’s largest rail franchise, Govia Thameslink Railway, change the time of every train – passengers have endured consistent delays and cancellations.

Witnesses at St Albans City station on Thursday morning described farcical scenes and said barriers were closed, staff were shouting and platforms were crammed.

“Hundreds of angry passengers outside barriers due to cancelled trains and crammed platforms,” tweeted Peter Saunders. “Angry people kicking down gates and pushing through. CEO resigned last week over shambolic new timetables. One gate had been damaged before I arrived by people forcing themselves through.

“All gates [were] then locked and people diverted to platform 1 entrance. One guy tried to climb over then started kicking gate as [a] staff member yelled at him.”

Further north, in Harpenden, there were similarly chaotic scenes where commuters were highly critical of the beleaguered train company and criticised “a month of unbelievably shocking service” from Thameslink.

“Forget schedules, we are way past that, no one had any idea what train was turning up,” said Charlotte Halkett, the managing director of a technology company in London.

“The boards just didn’t say anything, all we had was the station announcer telling us we think this train is possibly going to go there. There was not a timetable, just chaos, trains running riot in the wild which is just so dangerous.”

“People are just trying to get to work, or they’re trying to meet their children,” she added. “I think this is the first time it felt really dangerous.”

Network Rail, which maintains the track and signalling and power supplies, apologised to passengers in a statement.

“Our engineers have now fixed this issue and we are working with train operating companies to recover normal service as soon as possible,” a spokesperson said.

However, it warned of continued residual delays between Bedford and London St Pancras.

A Thameslink spokesperson also apologised. “For passenger safety we closed the gates at St Albans station for short periods to manage the numbers of people on the platform. Passenger announcements explained this.

“We encourage passengers whose journeys have been delayed by 15 minutes or more to claim delay repay compensation via the Thameslink website.”

The timetabling changes were supposed to increase the number of trains per hour, boosting passenger capacity by 40,000.

However, thanks to rushed introductions – over the course of three weeks rather than the usual 12 – drivers were unfamiliar with the new schedules and chaos has ensued.

GTR’s CEO, Charles Horton, said the company was “going through some very challenging times in recent weeks” when he announced his resignation on Friday. He recognised that “passengers have been hugely frustrated at the significant disruption caused by the introduction of new timetables”.

“It is the right time to hand leadership of GTR to a new pair of hands,” Horton said.

Patrick Verwer, the former managing director of train operator London Midland, will assume the role early next month.

On Tuesday Labour called for the railways to be renationalised and demanded GTR has its franchises terminated.

On Wednesday the leader of St Albans council demanded an urgent meeting with the rail minister, Jo Johnson, to discuss the chaos in a letter alleging that the consultation process on the changes to train services was unlawful.