Rail passengers described a “shocking week of poor service” on the line from London Euston to Birmingham and beyond.
West Midlands Trains routes have been disrupted every day since Monday, causing many cancellations or delays.
A shortage of train crew, plus problems with overhead electric wires caused widespread disruption to West Midlands and Virgin West Coast services.
West Midlands Trains apologised, saying its new timetable meant there were knock-on effects when issues arose.
Further disruption is expected on Saturday and Sunday, while strikes are planned for West Midlands Trains throughout the Christmas period.
Passengers took to Twitter to voice their frustration. One commuter said this week had been a “complete shambles” with only one of the trains she used running on time.
Another commuter, Imogen Handy, said she encountered a “stressful” week after experiencing seven delays or cancellations.
West Midlands Trains operates London Northwestern Railway and West Midlands Railways, running services from London Euston to Birmingham and around the Midlands.
On Monday and Tuesday, 55% of its services were late or cancelled, with 40% on Wednesday and 33% on Thursday.
Train crew shortages have affected routes all week, while travel in and out of Birmingham was disrupted on Tuesday after a broken-down train between the city and Wolverhampton caused delays and cancellations.
A loss of power to overhead wires between Watford Junction and London Euston caused major problems to journeys on other days.
West Midlands Trains apologised for disruption, saying a new timetable brought a “layer of complexity” which meant “when something goes wrong on the network, the knock-on effects were more significant and the disruption caused is greater than it would previously have been”.
It promised to take steps to fix things as quickly as possible and reduce the level of complexity by the next timetable change in December.
The National Union of Rail, Maritime and Transport Workers is planning industrial action on West Midlands Trains routes “over plans by the company to bulldoze through driver-only operation”.
Its members have been instructed to not book on for any shifts on seven consecutive Saturdays starting on 16 November.
“We will not allow the drive for profit to override the core issue of safe and accessible services for all on West Midlands Trains and we stand firm on that very basic principle,” said the union’s general secretary Mick Cash.
West Midlands Trains said if the strike went ahead, contingency plans were in place to run a skeleton service using managers.
“We remain determined to find a way of resolving this dispute without disruption and inconvenience for our passengers,” a spokesman added.
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