Siamese connections. You see them every day, but what are they exactly? Those pipes in front of buildings painted red, green, and yellow? Like fire hydrants, they are used by FDNY to fight fires. Why “Siamese”? They are called such because of their visual similarity to Siamese twins in that they encompass two pipe openings for a single pipe that leads either to the building’s standpipe, a vertical water pipe that leads all the way to the top of the building, or the building’s sprinkler system, or both. One opening is a backup for the other, in case the first is defective, though it can also be connected to a second hose if more pressure is needed.
In addition to sprinkler systems, standpipes are required in all buildings in New York City that are more than 75 feet tall, so that includes almost every building along SoHo Broadway. The first standpipes appeared in the 1860’s, around same time that sprinkler systems came into use. Before that, all firefighting was done with water from the outside of buildings.
According to a 2007 article in the New York Times, Siamese connections serve a vital function:
When there is a fire in a building equipped with a standpipe system, the first engine company to arrive connects a hose to the nearest hydrant and another to the Siamese connection in front of the building… The pumper boosts the pressure of the water being fed from the hydrant to the Siamese and then to the vertical standpipe.
Color coding indicates where the pipes lead: red indicates that it is connected to a standpipe system, green means it is connected to a sprinkler system, and yellow connotes a combination standpipe and sprinkler system. In addition, many Siamese connections wear spiky crowns that prevent people from sitting on them and tampering with them.
Now that you know what a Siamese connection is, no doubt you will see them everywhere. Notice that each one is unique and some of them seem to have personalities. Here are a few of the standpipes along SoHo Broadway, those silent sentries that protect us from harm, 24/7/365.
All photographs by Yukie Ohta, SoHo Memory Project