Govia Thameslink heavily underestimated rail disruption, with the actual result being 10 times worse
Govia Thameslink's (GTR) early estimates of how many trains would be cancelled due to its new timetabling were drastically different to the final outcome.
In a presentation to the Department for Transport (DfT) three weeks before the new timetables came into effect in May, GTR said there would be just 43 planned cancellations on its routes during the transition period, ITV News first reported.
On the first working day of the new timetables, the actual number of cancellations was 423, a ten-fold increase of its first estimate.
Other documents revealed that GTR management was confident that its preparations for any disruption were at "an advanced stage", flagging that there was an increased risk of cancellations but that communication with its train staff was "extensive".
The service is currently running on its third timetable in two months, as it tries to reduce the disruption caused by May's new running times.
Read more: Thameslink disruption continues despite third new timetable in two months
A spokesperson for GTR blamed the incorrect estimates on late approval of the final timetable by Network Rail, which it received around the same time as the presentation to DfT.
"After requisite consultations, this only left 3 days for driver rosters to be posted which indicates any misalignments between services, drivers, shifts, depots and route training," said the spokesperson.
"The industry protocols therefore broke down. What was discussed at the update with DfT was based only on what was known at that time."
A spokesperson for the DfT was keen to stress that GTR's presentation did not warn of the extent of the disruption that passengers would face, nor was the matter raised in a meeting with transport secretary Chris Grayling.
They added that the DfT was not advised of the full scale of the potential cancellations until two days before the commencement of the new timetable.
"An independent inquiry is being carried out to determine how this went wrong and to make sure this does not happen again," the DfT spokesperson continued.
"We are also conducting our own investigation looking at whether GTR has breached its contract and we won’t hesitate to take tough action against the operator if it is found to have been at fault."