The telephone failure of last Thursday, which largely stopped Dutch train traffic, appears to be the result of a broken telephone server in Rotterdam.

Rail manager ProRail announced this on Friday after an initial investigation.

According to ProRail, the backup of the broken server in Rotterdam also did not work, but the second backup in Amsterdam did.

However, between the switch from the regular system to the second backup, there was a period in which the telephone system was not yet working stable.

For safety reasons, it has therefore been decided to stop train traffic throughout the country.

Due to the malfunction, there was no communication with traffic control at various stations.

Train traffic could be resumed after just under an hour, but the train route remained disrupted for the rest of the evening.

In any case, this malfunction had a different cause than the telephone malfunction that affected train traffic on 31 May.

Then none of the backups worked.

After that incident, measures were taken to prevent a recurrence.

ProRail says it will further investigate the malfunction on Thursday.

Train traffic controllers communicate with the train drivers about incidents via the telephone system. For example, they indicate that they should drive slower if someone is walking on the track.