Many people stroll by them daily, oblivious to their significance, but these unnoticed fixtures are crucial for emergency services.
And now South Yorkshire Fire and Rescue has taken to social media to demystify the purpose of the yellow H symbols often spotted on lampposts, explaining their critical role in a viral TikTok video.
The viral clip, which has garnered more than a million views, reveals: “Point of view: You’ve walked past these small yellow signs your whole life but it was today you realised, finally, after all these years, they are there to tell firefighters where the hydrants are.”
These markers, also found on drain covers and street signs, feature two numbers within the prominent H. The upper figure denotes the diameter of the water main connected to the hydrant in millimetres, while the lower one shows how many metres away the hydrant is from the sign.
At times, an arrow may be included at the bottom to indicate the hydrant’s direction.
Cambridgeshire Fire and Rescue Service issued a statement saying: “Seen one of these yellow H signs in the street? These indicate that a hydrant is nearby. We use these to access the water main when we need to refill our engines or access an additional water supply. We may need to access a hydrant at any time, so please be sure to keep them clear.”
Commenting on the TikTok video, one user said: “I only learned the other week that they don’t carry all of the water on the trucks – so I’m doomed.”
While another added: “It’s nothing to do with me so I just walk on by. What do I need to know for? ” A third remarked, “I used to think it was H for helicopter landing.”
Someone else joined the discussion saying: “I had no idea and I am a teen I think we need to be educated on the real world as well as things like maths and science.”
Meanwhile, other users have stated they’ve been aware of this fact for years, with one commenting: “I was taught that in primary school.” And another shared a personal connection, adding: “My mum has one in her garden. I used to love it when the fire engine used to come and fill up.”