ETL 1110-2-553
30 May 97
removable and is normally procured by performance
type specifications showing dimensions, loadings,
materials, and other requirements such as HVAC,
lighting, insulation, and hardware.
(4) Special provisions. In cases where the lock
walls are subject to overtopping by flood waters, the
structures and controls have been designed so that
they are elevated or can be completely removed prior
to the flood. In other cases, bulkheads have been
provided to protect the controls and equipment from
A-2.
Control Systems
Figure 1-2. Melvin Price Lock central control
house
a. Introduction. There is some disagreement
over the extent to which computer technology can or
d. Control structures.
should be utilized for command and control of navi-
gation locks and dams. The degree of human intelli-
(1) Central control station. The central control
gence that can be replaced by automated expert
station is often a large, reinforced concrete structure
systems necessary to supervise and command the
with architectural treatment of the exterior walls
operation of a navigation project is debatable. While
(other construction types may be used). It is some-
some projects are fully or partially computerized,
times a part of a multi-use (administrative, operations
others are not computerized at all. Further, there can
and maintenance, and visitor) building and is always
be confusion when comparing computerized systems
located to provide a clear view of the tows and the
to traditional relay systems. This chapter puts the
lock operations. Closed circuit television (CCTV),
issue in focus by defining terms and presenting a
communication devices, supervisory operation and
historical perspective of the evolution of relay-based
control, data collection, and surveillance features are
and computer-based control systems within industry
normally provided for safe and efficient lockage
and the Corps of Engineers. Data is presented to
control.
compare the cost of the two systems for several
hypothetical lock and dam configurations. Finally,
(2) Fixed local control station. These buildings
conclusions are reached as to the applicability of
contain the control equipment to operate adjacent
computer-based systems to control navigation proj-
gates and culvert valves or even to control operation
ects. The semi-automated control system presented in
of the entire lock. They have been constructed in
this chapter assumes that lock and dam command and
place or have been pre-engineered and prefabricated.
control operations are initiated and supervised by
These structures are sized for the control panels
onsite personnel.
necessary for the lock operation and, if needed, con-
trols for bridges, emergency closures, and other
b.
Terminology.
equipment such as CCTV, computers, furniture, bath-
room facilities, and, possibly, provision for future
(1) PLC system. The computer-based systems
control systems. Heating, ventilation, and air condi-
utilize special purpose computers called program-
tioning systems (HVAC), where provided, are placed
mable logic controllers (PLC). The PLC performs
on the roof or in the side wall of the smaller
digital logic operations and was designed specifically
structures.
by the electrical industry for industrial use. There-
fore, for purposes of this document, a computer-based
(3) Portable local control station. The portable
system is referred to as a PLC system.
local control station is a similar structure to many
commercial prefabricated buildings used as parking
(2) Relay-based system. The traditional relay-
lot shelters or toll booths. It is designed to be
based system (RBS) relies upon electrical/mechanical
relays to perform the logic necessary to control
equipment. It is sometimes referred to as a
A-3
Previous Page
