Black S on warning triangle

[neilo5678]

Hi, any one able to shed light on what this sign is? I’ve looked through lots online and can’t find an answer.

Thanks

 

[Gaelan]

@Railsigns has it: https://www.railsigns.uk/sect11page2.html

Before all goods trains had been fitted with continuous automatic brakes, it was common practice to install catch points on running lines, below steep rising gradients. The point switches were usually held in the derailing position by a spring, to arrest any vehicle running back in the wrong direction.
[...]
In August 1974, British Rail introduced a standard design of catch points sign comprising a letter "S" (for "spring") on a solid white triangle [11.32]. These signs are normally double-sided and are positioned either on the approach to the points in the facing direction or at the toe of the points. These signs are also provided at unworked trailing points.

 

[Efini92]

@Railsigns has it: https://www.railsigns.uk/sect11page2.html

It’s worth noting that even when the catch points are removed the signs often aren’t.

 

[neilo5678]

Thank you so much. I looked on there for ages must have missed/not seen it. Thanks again