Great Western Coffee Shop

One bogie of the rear coach off the track.
Said to have been at low speed, no serious injuries.
District line also blocked.

SOURCE BBC news.http://www.bbc.co.uk/news/uk-england-london-41883153 (http://www.bbc.co.uk/news/uk-england-london-41883153)

As my Waterloo bound train left Wimbledon this morning I wondered why there was a policeman with a rail worker standing on the District line tracks. I then saw multiple emergency service vehicles parked in Waitrose next to the tracks. Whats going on? I wondered. I saw lots more people in Hi Vis standing on the tracks. And then a blue SWT SWR train with its rear carriage at a different angle to the rest of the train obviously derailed. It was blocking the District Line tracks but was clear of the Main and Suburban lines.

From memory a very small number of early morning / late night trains in passenger service divert on to the District Line between Wimbledon and East Putney. That section of the District Line is owned by Network Rail.

The first train up from Basingstoke lost its last bogie set which went on the up line instead

The RAIB has released a safety digest following this incident:

https://www.gov.uk/government/publications/safety-digest-012018-wimbledon/derailment-of-a-passenger-train-near-wimbledon-south-west-london-6-november-2017

Was I the only person who found that very entertaining - showing an unexpected talent for comedy in both Network Rail and London Underground?

I don't think its funny at all (hope you made your comment in jest).  This is another example of how NR constantly claim that they brought asset management under control after the Railtrack 'fiasco'.  They really don't know after 14 years do they?  When I worked for NR we were pushed very hard into reviewing and making lists of all of our discipline assets.  Its quite concerning that,once again, NR is not as perfect as it claims.......

But surely that is 'how things are these days'? Those on the ground know the problems that exist; constantly pass those higher up the chain where the problems magically disappear. Eventually you get fed up with reporting.  When things go pear-shaped it's the ground crew at fault.
I'm not bitter; just getting old!  :'( :'(

But NR (apparently) has a 'perfect' asset management and defect reporting system (for which a lot of money was paid back in 2004/5).  How then did such a simple issue get missed?  It's very concerning to me that such a simple boundary should have been documented in error.  In my old area we had quite a few internal and external boundaries and I don't remember any of those having 'gaps' in them like this one.  Good job it was a fairly low speed area.

What happened at privatisation of Railtrack was an enforced deletion of a huge archive of asset management data unwittingly at the behest of DfT who decided the privatisation model.  That was the data held by the local people on the ground who were outsourced, moved to other areas or simply left the industry.  You do not recover that information easily - indeed some is lost forever.  What is worse is that some of it is information that you do not know that you do not know. So you can never know you have a perfect asset management system - it is always learning.  You also have to ensure that the information in it is properly communicated to the staff on the ground.

I suspect that this gap in inspection dates from that time and often happens as a result of reorganisation.  In my own sector I am aware of a key asset that went without inspection from 1974 until about 1982 - fortunately without incident.  The reason being a reorganisation forced by legislation leaving no-one looking after a boundary asset. 

I would be very surprised if NR had ever claimed to have a 'perfect, Asset Management system - though they might have claimed to have one that is greatly improved.  Indeed such a system is only as good as the data that is in it. 

I trust that this incident will have caused NR to review all such boundaries and ensure that they are properly marked on the ground. 

From RAIB:

How can the gauge increase by more than 50mm? - what do the fastenings to the sleepers look like by this stage?

The sleepers may be the issue here, as in rotten wooden ones?