Fire Hydrants

A fire hydrant on King St. in London. Derek Ruttan/The London Free Press/Postmedia Network

Wonder why London fire hydrants suddenly glow?

It’s all about the flow.

Colour-coded, reflective markers have been installed on all fire hydrants in the city, to tell firefighters how how much waterworks to expect.

Where time counts, it’s all to help firefighters decide what size of hose and what pump settings to use.

While dispatchers are equipped with maps that give firefighters the same information, the new tags make the process easier, said Dan Huggins, London’s water quality manager.

“All of our hydrants are going to provide water and some can provide more than others. This is a way for the fire department to know what flow range they are working in,” he said.

The city began fitting hydrants last fall with the reflective markers, which are shaped like the Maltese cross that firefighting borrowed from the Crusades as a sign of bravery and loyalty.

It cost about $80,000 to fit 9,000 hydrants with two markers each.

Blue indicates the highest flow range, 95 litres a second, and red the lowest at less than 31 litres.

Green- and orange-marked hydrants fall in the middle.

A hydrant’s water flow depends on the available pressure, and the size and condition of the water line.

While water pressure typically depends on elevation, other factors can affect the flow.

The highest water pressure is along the Thames River, said Huggins.

But in areas where old cast iron lines deliver the water, the flow is less.

“They rust inside” and restrict the flow, he said.

Municipalities are required to colour-code all hydrants but have a variety of options.

While many cities paint hydrant tops, firefighters say the reflectors are highly visible.

“In cases of snowstorms, or at nighttime when it’s a little harder to find them, it helps us find the hydrants,” said fire inspector Robert Barker.

[email protected]

twitter.com/obrienatlfpress

Source: London hydrants ‘glow’ with the flow | The London Free Press