Swan Neck in Hong Kong

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The Water Supplies Department released the standard drawings of Swan Neck on their website. Look for WSD 1.55 - Swan Neck Fire Hydrant and Cap (Type II). You can check it out if you are interested in the technical specifications of a Swan Neck hydrant.

This type should not be confused with Double Head Swan Neck, which looks very different from a normal Swan Neck.

Okay, so Swan Necks painted in red use fresh water and those painted in yellow use seawater, anything else that is noteworthy?

Swan Necks painted primer grey

I managed to find three Swan Necks painted in primer grey since their installation during the pandemic - at least four years ago. They are all unnumbered, and only the one on 82B Waterloo Road shows up in GeoInfo Map.

Swan Neck cap connector

While most Swan Necks I've seen have the cap connector shown in WSD 1.55 (which I will refer to as the "standard cap connector"), I found two Swan Necks with a different cap connector, which has a more angular shape. I will also provide photos of Swan Necks with the standard connector for comparison.

Swan Necks that are not a single pipe

WSD 1.55 describes the Swan Neck as a "stainless steel pipe", and indeed most Swan Necks I've seen are just "a single pipe". But like with many things, there are exceptions. So far, I found seven Swan Necks made of joining the curved and straight sections. The two section design is actually shown in another Water Supplies Department standard drawings: WSD 1.34 about hydrant painting, in which a white band would be painted on the joint section if the Swan Neck is connected to a trunk main. But WSD 1.34 is not a standard drawing specifically about Swan Neck and the joint might just be an exagerated representation of where the white band was to be painted. There is also a weird variant of the two-section Swan Neck on Tsing Tsuen Road bridge, the joint section of which is actually a valve (but without the handwheel). If you check the Swan Neck with valve on Google Maps street view, it was mostly red with hints of yellow beneath the red in Y2009-M04, but most of the red had weathered away and it looks yellow again by Y2026-M05.

The funny front profile of Swan Neck

This is not really anything extraordinary but I think it is worth appreciating just how low profile Swan Necks are when viewed from the front. After all, a Swan Neck is just a "stainless steel pipe".

Swan Neck (?) outside Lutheran Theological Seminary

There is a Swan Neck-like hydrant outside Lutheran Theological Seminary. More details about the wacky custom hydrants at Lutheran Theological Seminary in this page.

Swan Necks are historic

The earliest mention of Swan Necks I was able to find was in a 1959 memo, in which Swan Necks were proposed to replace the Ground Hydrants installed in San Hui Market (Ground Hydrant was a type which I believe is no longer found in Hong Kong except in Chek Lap Kok airport). While it is not clear if the Swan Necks mentioned in the 1959 memo was the same Swan Neck design we know and love (or I guess not, because people online rarely talks about Swan Necks), I think it is fair to say that the Swan Neck design (or I suppose the concept of a single outlet hydrant) have been around for 67 years. So yes, even though people online always talk about how the "Octagonal hydrant" is historic, Swan Neck is equally if not more historic. As for Heavy Draw-off Hydrants, they didn't exist in 1959 so Swan Neck is more historic!