How powerful is a fire truck hydrant

Article youth

“Turn it up like a soda bottle.” Emirhan has to think about the announcement from youth group leader Timo Lehmann: right or left? Usually you do that quite mechanically. The eleven-year-old has to think twice about the standpipe key. Then he pushes the iron, which is over a meter long, to the left, i.e. the right way round, to clear the water. The air hisses, the water gushes from the underground hydrant into the standpipe.

The Lauffen fire brigade is testing a project that is unique in the district, says the head of the youth brigade in Hölderlinstadt, Timo Kraft. For the first time, the firefighters are cooperating closely with the Werkrealschule. There have been visits more often. But at the last meeting, headmaster Christian Müller and Kraft established the cooperation.

Tuesday is the fire brigade

In addition to the existing working groups, the students at the Werkrealschule in Lauffen now also have the option of choosing the fire brigade as a working group. This gives them one afternoon off, but they have to go to the warehouse at Raiffeisenstraße 1 every other Tuesday.

The cooperation should run the whole school year. Kraft hopes that this will create a long-term relationship with the fire service. That is why the four boys and one girl who decided to join the armed forces were also accepted as members of the youth fire brigade. If you do not like the offer, you are released from the obligation to visit, which is documented, again after one year. The fifth graders are motivated and listen carefully to what firefighter Timo Lehmann tells them about the various hydrants in the city. There are hundreds of them in Lauffen, all of which are hidden in the ground. They are therefore called underground hydrants.

How strong is eight bar pressure?

The so-called standpipe, which is screwed onto the water inlet, has two outlets. Two hoses can be connected to this. In order to get the necessary pressure of eight bar, the fire brigade would now switch on a pump. It could deliver up to 2500 liters of water per minute, but the line only produces 800 liters. “40 liters per minute are sufficient for an internal attack. The only important thing is the pressure, ”says Kraft. And that's enough from the C-tube for a width of 50 meters.

Kraft tells the inquisitive children that you can even cut metal with high water pressure. In industry, a pressure of 5000 bar and more is used. Nevertheless, Lehmann warns: “It's best to move to the side.” Not because it would hurt if the jet of water from the standpipe hit one of the little soldiers. You would just get dripping wet. And when the outside temperature is six degrees, the cold is safe.

The hydrants have almost disappeared from Lauffen

A red pillar a few meters further arouses the children's curiosity: It's an overground hydrant. There are only four or five of them left in the city, mostly in public buildings. The red hydrants from American films are well known. If a car drives against it, the meter-high column of water hisses out. “It's not the case with us,” says Kraft. The hydrant is secured. Before water even comes out of the pipe, Emirhan and Nina (13) unscrew the eight-centimeter-thick hexagon screw with the hydrant wrench. That takes a lot of strength.

Nina was paying close attention. The fire brigade has good options for fighting an extinguishing attack in the city. “But what about a forest fire?” She asks. Kraft: "In Lauffen we have two vehicles with 2500 liters of water each on board." If that weren't enough, the overland aid comes from Heilbronn. The comrades have two tank trucks that hold a total of 22,000 liters. If necessary, the Lauffener Wehr can build up a water supply through hoses over long distances.

It goes without saying that it is now the vehicle's turn: lighting and signaling devices, breathing protection, tools, pumps - the fire engine has all kinds of material on board. Lots of learning material waiting for the students in the next few months.