Fire! Fire! Is Your Hydrant Blue-Topped?
If your fire hydrant is red-capped...
.....I suggest you start making noises at the next Council Meeting. Red-Capped fire hydrants are the least efficient; you want a fire hydrant with a Blue Cap.
Fire Hydrants, or fire plugs as they are sometimes known, are like shop assistants; they are ignored until they are needed, and then they cannot be found. The only time anyone sees a fire plug is when they want to park at the roadside and there is a hydrant on the sidewalk. It will have that smug smile on its face as it shakes a finger and says ‘naughty, naughty, not here, you don’t’.
Have a closer look at the next lot of hydrants you see. You will probably be surprised at their locations, as well as at their different colours. Most of the hydrants have an ochre yellow body, but the caps and outlets are – or should be - different colours. The ochre yellow makes the fire plug easily distinguishable, and the cap shows the firemen how much pressure there is in each one.
The colour coding follows NFPA 291. The National Fire Protection Association is a standard that is supposed to be followed world wide, and rule number 291 deals with the colour coding of the hydrants. In Canada, the Ontario Fire Code follows NFPA 291, and the hydrants are coloured as follows.
There are 4 main colours for the caps BLUE, GREEN, ORANGE & RED.
The blue capped hydrant has a water flow of 1,500 gals per minute.
The green capped hydrant's water flow is from 1,000/1,500gals per minute.
The orange capped hydrant's water flow is from 500/1,000 gals per minute.
The red capped hydrant's water flow is less than 500 gals per minute
The upright multi coloured hydrants seem to be a North America quirk. The Canadian hydrants are unsightly. When questioned about the fireplug’s raisin d’être, the answer that is usually given is one word - Snow. This makes no sense at first; the United Kingdom has snow, but there the fire hydrants are hidden under manhole covers. Sometimes there is a metal sign on a nearby wall with a large yellow 'H' marked on it, to denote the postion of the hydrant.
It only takes one winter in Canada to understand the ‘snow’ answer. The snow that falls in November and December is still on the ground at Christmas. Added to that snow, are the heavy falls of January and February. The snow ploughs and snow blowers clear the roads and paths all winter, but the snow is still there – it has only been moved. And what is really freakish is the fact that those ginormous mountains of snow are still there in May.
The 'snow' answer also explains the reason for the tall bright yellow extensions bolted to the top of the hydrant; they’re called ‘hydrant finders’. You can appreciate this better by looking at the photograph of the mail boxes.
Because of the risk of the water freezing in Canada after the hydrant has been used, the hydrants are of a 'dry barrel' design, where all the water flows back down into the mains pipe, leaving the above-ground barrel free of water. Also, to make extra certain that the water will be there when needed, the hydrant is connected to the mains water pipe beneath the frost line – at least 1.5 metres down.
1,000 Gallons per Minute
And, the request that you stay 15 feet away from a fire hydrant isn’t just because the fire engine needs to get near to the plug; it’s also to protect your vehicle. When the hoses are connected and the water is turned on, the hoses, which may have been bent, will straighten out under the immense water pressure. As the swollen hose becomes rigid, it will make short work of your car.
There is already pressure in the water system, caused by either the gravity feed from the local water tower or from being pumped from reservoirs. This pressure is enough to ensure functioning faucets, closets, washing machines and etc, but is not enough to pressure a fire hose. The fire engines pump the water from the hydrant to dowse the fire, but the pressure used depends on the diameter of the pipes feeding that particular hydrant. But because of the colour coding, the firefighters will know what diameter of hoses to use, and whether they need to take a feed from more than one hydrant.
Fire engines hold anywhere from 750 to 1,000 gallons of water in their tenders, in case there isn’t a handy fire plug. And even if the red-capped hydrant is the closest one to your home, the fire engine has an average of 900 gallons for initial use. The only snag is that the fire engine can pump water at over 1,000 gallons a minute, which means it could be empty in less than 60 seconds. But then, your locale will have more than one fire engine.
[This reminds me of a visit I made to a Navy Frigate last year. A Leading Seaman explained to me that the gun on the forecastle was intended for use against smaller vessels. “It fires 4 shells a second,” he explained succinctly “Tick, Tock – no small vessel.”]
Off you go and check your nearest fire hydrant. There are other figures and letters printed on the hydrant which give the fire fighters more information, such as the distance to the next hydrant, and its pressure.
Of course, you may live in the countryside, where a fire plug is as much a rarity as piped water.
P.S. I couldn’t find any orange hydrants.