“Coach becoming uncoupled on a train” at Welham Green - 10/10/2026

[Krystal]

Around 3pm, a Moorgate train at Hatfield was held for over 13 minutes. The reason was due to a train in front of it having a coach uncoupled. This is what was written on the National Rail Enquiries page:

A coach becoming uncoupled on a train between Welwyn Garden City and Alexandra Palace means some lines towards Alexandra Palace are blocked.

Appears to be 5Q46, which was (apparently) a HST running from Welwyn to the Mid Norfolk Railway. Not ten minutes after it departed the freight depot did it stop between Hatfield and Welham Green due to this. Because of this, the Up platform at Welham was blocked and Moorgate trains had to use the fast platforms at Brookmans Park and Potters Bar, delaying fast trains behind it.

Firstly, what was the occasion for this train running in the first place, and secondly, how on earth could something like that happen, especially so early in the journey?

 

[Failed Unit]

The train has being at Welwyn Garden City in the sidings for a few days. I assume it was doing some testing. I have seen them swapping power cars the network rail yellow ones were put on instead of blue shabby ones with the train.

It is very possible that something wasn’t connected properly at Welwyn Garden city. But that is speculation.

The train at Welwyn Garden City is fact. I can’t remember if it was Wednesday or Thursday evening they were swapping power cars.

 

[Trainman40083]

42379 is the coach. A few yards down the track is one of the Rail Adventure HST power cars that are still in former East Midlands Trains blue livery.

 

[Kentish RYS]

42379 is the coach. A few yards down the track is one of the Rail Adventure HST power cars that are still in former East Midlands Trains blue livery.

Has anyone seen close enough (I suppose it depends on where it all stopped in reference to places you can see) to see if the coupler on either the coach or power car broke? I understand it may not be obvious as that though.

 

[Mag_seven]

For a discussion of the history of such "detachment/uncoupling" incidents please use this thread:

Trains that became detached.

Moderator note - split from: https://www.railforums.co.uk/threads/%E2%80%9Ccoach-becoming-uncoupled-on-a-train%E2%80%9D-at-welham-green-10-10-2026.308057/ Has certainly happened before, a 150 splitting apart at Leeds springs to mind. Whatever happened however, seems to have been resolved as...

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