THE UNIVERSITY OF HONG KONG
CCST9074 Water: Resources, Policy and Technology
Field Trip Report
2021-2022
Name
UID Number
Tutorial Group
Title of Report
Tai Tam Waterworks
iVacAir
With the ever-growing demand on water supply in Hong Kong, strategically
planned development was carried out from time to time. These water supply
and treatment system are found to be started in the mid-eighties. With the
virtual field trip, a chance to Tai Tam Waterworks was provided. The Heritage
of Water Infrastructures opens a whole new chapter of water supply system in
1850s and has proved to be an integral part of nowadays water supply network.
In this report, several main structure of the reservoir, dam and pumping system
will be discussed.
Reservoir Structure
The Tai Tam Upper Reservoir, Tai Tam Byewash Reservoir, Tai Tam
Intermediate Reservoir and Tai Tam Tuk Reservoir were built in several stages,
all now are monuments with high historic value. They are proved to be very
effective water saving facilities in the water supply system. As mentioned in the
virtual field trip, masonry bridges and aqueduct were built which the piers and
columns hardened by moulded capitals or corbels to provide the best support
(Figure 1). The usage of concrete corbels is very common in connecting precast
concrete structures. Experiments show that by testing the corbel strength and
cracking between column and corbel, a reinforcement in the form of a loop
provides the best performance to decrease probability of cracks. [1] This can
be found on both masonry bridge and masonry aqueduct (Figure 2).
Dam Structure
The reservoir dam stores water before gravitationally transferring water through
tunnels to Central district. Granite was chosen as the main material for Upper
Reservoir Dam construction (Figure 3) whereas concrete was chosen later for
the Byewash Reservoir Dam and Tai Tam Tuk Reservoir Dam (Figure 4).
Granite fragments has a lower strength and will deteriorate faster when
comparing to concrete. The choice of using concrete in later stage of the Tai
Tam Group of Reservoirs shows the knowledge of material engineers at that
time. On each dam, valve house is found mainly built by rock-faced rusticated
granite (Figure 5). These houses are built on projecting platforms, serving as
the inspection location of the dam and control center for the dam valves.
Water Pumping System Structure
The Tai Tam Tuk Raw Water Pumping Station plays the important role of
pumping water to the city center (Figure 6). By then, steam drive pumps were
the key to perform the task. According to Figure 7, the pump works under the
energy conservation from the cylindrical tank B, passing the movable beam E
to the water pump rod R. After the steam enters the tank from A, water is
injected from V1. The steam condenses, pressure inside the tank reduces and
a vacuum is created. Under atmospheric pressure, the piston (P1) will be forced
down and lift the pump rod on the other side. Water will then be pumped out.
[2] This water pumping mechanism is well-known as the Newcomen engine.
Overall, the civil structures and systems of Tai Tam Group of Reservoirs shows
remarkable engineering techniques at that time. Till now, the reservoirs are
preserved and remains in good conditions. Acting as one of the main water
supply systems for Hong Kong Island, the Tai Tam Group of Reservoirs should
be protected and promoted. It is hoped that more people will learn to admire
the water supply complexity and learn to save water.
Figure List
Figure 1 Hardened Structures by Moulded Capitals or Corbels
Figure 2 Corbels found on Tai Tam Upper Reservoir Masonry Bridge
Figure 3 Tai Tam Upper Reservoir Dam with Granite Structure
Figure 4 Masonry-faced Concrete Tai Tam Tuk Reservoir Dam
Figure 5 Rock-faced Rusticated Granite Valve House
Figure 6 Tai Tam Tuk Raw Water Pumping Station
Figure 7 Newcomen Engine
Reference List
[1] de Lima Araújo, D., de Oliveira, E. M., Silva, E. M. O., Coelho, S. A., & El
Debs, M. K. (2021). Experimental analysis of a modified two-step corbel for
precast concrete system. Engineering Structures, 242, 112585.
[2] Sam M. (2019). Earliest steam engines used to pump water.