Leading enterprise and diversified conglomerate Nan Fung Group (the Group) launched Episode III of its fascinating “In Time Of” series of community initiatives. In this episode, “In Time Of” has partnered with The Conservancy Association Centre for Heritage (CACHe), a local organisation that advocates social awareness of heritage conservation, to present the “Manhole Covers Exhibition” at Nan Fung Place, Sheung Wan. The unique exhibition showcases a selection of the city’s manhole covers to encourage the public to discover the history and industrial story of Hong Kong from one of the most common, yet rarely examined, aspects of the urban landscape.
Inspired by the global concept of the Resilient City, the idea behind the “In Time Of” programme is to encourage the public to appreciate and rediscover the intrinsic and overlooked beauty of the neighbourhoods. The programme brings together a diversity of social stakeholders including non-profit organisations and social enterprises to develop sustainable community programmes spanning from culture and arts to social design. In this way, the Group hopes to promote greater social empowerment, and improve the efficiency of resource utilisation in the hope of creating a more resilient future for the city.
Tracing the growth of Hong Kong’s modernity with manhole covers
Visitors will be able to learn more about Hong Kong’s urban development by interpreting the information on the manhole covers and discover how the city developed through different kinds of infrastructure. The idea is to stimulate the effective use of natural resources and provoke discussions on how urban design in the future can be improved and integrated into our daily lives.
While walking along the main streets and alleys, people rarely pay attention to the humble manhole covers under their feet. But in fact, they are an indispensable part of the city’s public facilities and infrastructures. They serve as entry points for workers to conduct underground inspections of vital utilities and ensure that we all enjoy reliable water, gas, and electricity supplies as well as the broadband networks which all help to maintain our comfortable lives. The covers also act as openings for an advanced urban drainage system that protects residents against flooding under extreme weather conditions. They have also had a long historical development in Hong Kong. Their unique and evolving designs, materials, and production technology illustrate the century-old development of the city’s pig iron casting industry and the evolution of public works.
To enable workers to easily identify the functions of each manhole cover, they all bear different patterns and codes that identify different government departments, drainage contractors, manufacturers, and loading capacity. The varied colors, shapes, and symbols on the covers are all designed with specific meanings.
For example, the square cast iron manhole covers named “Big Belly Button” were designed in two patterns and commonly used during the 1950 and 60s. According to a “round for rainwater, square for sewer” theory developed by industry insiders in the past, the public can observe the usage of the covers simply by looking at their patterns. The round and radical pattern indicates the cover is for a stormwater drain, while the small square pattern indicates the cover is for a sewer.
Before the 1990s, manhole covers engraved with the symbol “F↑H” were not just for Fire Hydrants, the arrow in the middle, known as a “Chicken Foot Mark”, meant it had been directly purchased by the Government Supplies Management Division before changing to public contractors in the late 1990s.
To improve garbage filtration and drainage efficiency, gully gratings with diagonal slots used to be equipped together with overflow weirs known as “stool chairs” and gully traps which are also commonly called “curry tanks”, to provide safer road conditions and a more convenient city life for us all. Due to the heavyweight of cast iron manhole covers, some of the original designs and materials are no longer in use and have been gradually replaced by more expensive stainless-steel covers to increase overall efficiency. These are just one example of how advances in technology have affected the development of the local cast iron industry over years.
Manhole covers are still a sign of the times. Which is why Sheung Wan, with its long neighbourhood history, has been chosen as the area for the Manhole Covers Exhibition. The exhibition includes topics like, “Decoding Manhole Covers” and “The Emergence of Cast Iron Manhole Covers”. Manhole covers from around Sheung Wan are showcased at the exhibition with detailed notes that enable visitors to distinguish the types and characteristics of manhole covers. It also introduces local foundries and craftsmen as well as the manufacturing process of manhole covers.
To enhance the experience, a Manhole Covers Map is created in the exhibition leaflet, encouraging visitors to explore the manhole covers and its interesting stories in the Sheung Wan area. An online audio manhole covers guided tour is also hosted by CACHe on social media for the public to trace the fascinating history and hidden stories behind the manhole covers from different eras.
A series of original products designed by Concretology under the theme of Hong Kong manhole covers are displayed at the exhibition. Visitors who are interested in preserving traditional and human street stories can purchase them from Concretology’s online store.
Episode III: In Time of History – “Manhole Covers Exhibition”
Venue: 1/F – 2/F, Nan Fung Place, 173 Des Voeux Rd Central, Central, Hong Kong
Date: 1st April 2021 to 30th April 2021
Time: 10AM – 8PM
Please register online for admission: https://www.popticket.hk/event/manhole-covers-exhibition