RAIB have
released a statement regarding the collision which occurred at Salisbury on Sunday evening.
It confirms what a few people were wondering which was if one of the trains had passed a danger signal due to poor adhesion.
It's unusual to get this much detail from a statement saying they are investigating, but I'm glad they have done as it puts a lot of questions to rest right away.
Was a very nasty accident and whilst it is fortunate no one was killed and that it wasn't human error, it's still incredibly saddening to hear one of the drivers suffered life changing injuries
For those who don't know, basically what happened was a GWR service was signalled normally through a converging junction heading into Salisbury. At the same time however, a SWR service was attempting to slow for a red signal protecting that junction, but encountered low adhesion. Despite the drivers' attempts to stop and even applying the emergency brake, the train continued to slide through the protecting signal, and collided with the side of the GWR train passing over the junction resulting in both trains partially derailing, and extensive damage.
What annoys me is the number of times over the years I've heard the general public laugh at reasons like "leaf fall, wrong type or snow/rain" and such things as "stupid excuses" and thinking we make things up.
This is exactly the reason why these reasons are not 'stupid'. Leaf fall season can be incredibly risky and dangerous, especially with other weather conditions too. If anyone ever laughs or complains about 'stupid excuses' like leaves on the line and poor weather, I'm referring them to this example of why we have to be careful.
I recall reading a few years ago about an incident with Scotrail Service which occurred in the early 2000s, 1B47 I believe it was, which slid for nearly 2km in emergency braking due to very poor rail adhesion.
I've been caught in wheel slides before and they can take you by surprise suddenly. Some can be kinda interesting in a way, but other times they can be quite terrifying if you're trying to slow for a reason and can't tell if the train is going to slow and stop where you want it to.
Metal wheels on metal track is fantastic for high speeds and low rolling resistance. Bloody awful for adhesion in bad weather though, especially when you consider the total surface area for each axle contacting the rail is going to be far smaller than that of just a 5pence piece!