We usually think of load shedding in terms of dark homes, silent factories and uncharged phones. On a modern bridge, however, a power cut can also switch off the eyes, ears and memory of the structure.
The New Nile Bridge is made of concrete, steel and stay cables, but it also depends on electricity. Its weather transmitter measures local conditions, the GPS receiver watches for movement and deformation, and the dummy cable records temperature changes. Load cells and the automated control system use this information to keep the stay cables responding properly as temperatures rise and fall.
The bridge has two standby generators, which provides important backup. But generators are useful only when they are serviced, tested and supplied with fuel. A generator without diesel is simply a large metal promise, and two empty generators do not amount to redundancy.
Reliable backup power therefore requires more than purchasing the machines. It needs automatic changeover, low-fuel alarms, a defined minimum fuel reserve, regular testing under load, scheduled servicing, updated maintenance records and a dependable arrangement for emergency fuel delivery. Most importantly, someone must be clearly responsible for checking that all this is done before the emergency arrives.
What happens when the bridge remains without power for too long? At first, batteries and other backup systems keep the instruments running. Once those are exhausted, data transmission may stop, gaps begin to appear in the bridge’s health record, and engineers lose the continuous information showing how the deck, cables and towers are behaving.
If the outage continues, the automated system that uses temperature and load readings to manage cable tension may also be interrupted. This does not mean that the bridge suddenly collapses. It means the structure becomes less able to report its condition and less able to respond through the systems designed to keep its behaviour in order.
That is how infrastructure risk often develops. It rarely arrives with drums, sirens and a press conference; it grows quietly through missing data, delayed alarms, exhausted batteries, untested generators and maintenance decisions postponed until tomorrow.
Frequent power cuts create another problem. Repeated switching between the grid, batteries and generators increases wear on batteries, control panels, communication equipment and sensitive electronics. Poor servicing or delayed refuelling can eventually turn expensive backup equipment into very sophisticated roadside decoration.
Reliable electricity must therefore be treated as part of bridge maintenance. It is no longer enough to inspect concrete, repaint steel and repair the pavement. Modern bridge maintenance also includes sensors, software, communication systems, control equipment, generators, batteries and fuel supplies. An intelligent bridge cannot remain intelligent when it is repeatedly put to sleep.
I am currently supervising the construction of the maintenance garage that will house the specialised vehicles used to maintain this remarkable national asset. It is one of the many quiet investments that will help the bridge continue serving the country safely and reliably for decades.
The reassuring part is that the New Nile Bridge is not being left to look after itself. It has a dedicated team that inspects the structure from the roadway, from beneath the deck and from inside its enclosed cells. The team services equipment, maintains access, keeps the backup systems ready and even enters and cleans the internal cells of the bridge deck.
The bridge may have sensors, automated controls and two standby generators, but none of them can inspect a fuel tank, order diesel, clean an internal cell or sign a maintenance record. Intelligent infrastructure still depends on disciplined people doing ordinary work consistently and on time.
Most of us cross the bridge within a few minutes and continue with our journeys. Its caretakers remain behind, working above it, below it and inside it, to keep this important national asset safe, awake and ready for the next crossing.
The post APOLLO BUREGYEYA: When an intelligent bridge loses power appeared first on Watchdog Uganda.