Well ... since I started this thread I've noted:
This is due to a broken down train.
This is due to a delay on a previous journey.
This is due to a line-side fire.
This is due to a member of train crew being unavailable.
This is due to a passenger being taken ill.
This is due to a problem currently under investigation.
This is due to a problem with line-side equipment.
This is due to a security alert.
This is due to a train fault.
This is due to a train late from the depot.
This is due to an earlier problem at a level crossing.
This is due to an earlier problem with line-side equipment.
This is due to an earlier security alert.
This is due to an earlier train fault.
This is due to an obstruction on the line.
This is due to an unusually large passenger flow.
This is due to animals on the line earlier.
This is due to animals on the line.
This is due to congestion caused by earlier delays.
This is due to disruptive passengers.
This is due to earlier emergency engineering works.
This is due to earlier signalling problems.
This is due to over-running engineering works.
This is due to passengers transferring between trains earlier.
This is due to safety checks having been made earlier.
This is due to signalling problems.
This is due to speed restrictions.
This is due to train crew having been unavailable earlier.
This is due to unusual passenger flow.
This is due to waiting earlier for a train crew member.
This is due to waiting for a train crew member.
Which seems to be a far better / wider range that I had aniticipated
.
Noting the number that say "earlier" in them, knock-on effect is a clear issue that (?) makes the number of significant delays and changes later in the day far higher than earlier in the day (?). In another thread, we were discussing
FGW▸ tweet hours and wondering if they should be slid an hour earlier. I'm thinking "probably not" ... if the passenger levels are similar, Jo and Ollie are likely to be far more useful in the evening reporting and helping on after effects that first thing in the morning when the morning specials are usually limited to a few "train late from depot" and "overrunning engineering" issues.