Did you know that rooftops are an excellent place to locate sprinkler tanks serving high-rise buildings? In fact, across the Pond, in New York, many of the city’s apartment blocks have them. Out of sight but always on standby, they are the unseen fire safety essential that serves sprinkler systems.
Water tanks have been constructed on rooftops for almost 100 years. They were first installed in commercial buildings in the US following devastating fires. Scores of people perished in garment factories alone. This prompted authorities to introduce regulations. New fire safety rules covered high-rise buildings used for residential as well as business purposes.
Fascinating history of rooftop fire tanks
While initial regulations required the ready supply of water, it quickly became apparent that rooftop tanks were needed. This was because water pressure is often very poor after the fifth storey. While sprinkler systems are not always a feature of high-rise buildings in the UK, they have been an essential part of fire prevention in New York for more than half a century.
Harris Rosenwach first came up with the idea of building a water tank on a roof. Today, his great-great grandson, Henry, is vice-president of Rosenwach Tank Co, headquartered in Long Island.
In the UK most fire tanks are made of sheet metal and constructed on-site, although they will have been prefabricated elsewhere. Built to individual specifications, fire tanks are rarely the same.
How do rooftop sprinkler tanks work?
Think gravity. It is as simple as that. Add electricity and you’ve got the two basic forces that deliver life-saving water to sprinkler heads. Sensors in the tank ensure water levels remain constant. Extra water is delivered when sensors detect a drop. Sometimes a floating balloon is used instead – like the ones you find in toilet cisterns.
With proper maintenance, a steel fire tank can last decades. In the UK, there is no need to empty a tank and clean it before an inspection. Underwater camera equipment is used to survey the tank’s walls and potential weak spots. Companies that fail to have their tanks inspected annually in the US can be fined up to $2,000.
UK sprinkler tanks and fire safety