Urine, Corrosion, And The Decay Of Bridges

You have to feel sorry for designers, particularly bridge designers. How can you factor in all the variables that will determine whether your bridge survives?

Take for example, a bridge in Palembang, on the Indonesian island of Sumatra. Built between 1962 and 1965, the 1,177-meter long and 22-meter wide bridge was named after the then president, Sukarno. When he fell from grace it was renamed Ampera (short for Amanat Penderitaan Rakyat or the Mandate of People’s Pain, according to The Jakarta Post, In Memory Of The Suffering of the People, according to others. They were difficult times and bridge namers were not given to levity). It is a distinctive-looking bridge, with two tall towers standing like guillotines above the Musi river. It is, in short, the pride of the region.

photo by Audy Mirza Alwi

It has been repaired a few times. The Post says it was renovated in 1981 after fears that flaws in the original construction might cause it to collapse. More recently the Japanese have funded (PDF) efforts to rehabilitate the bridge, especially after some serious underwater damage (mindful, no doubt, that the bridge was originally funded by war reparations from the Pacific War.) Despite some problems (like ships bumping into the bridge), the Japanese were able to report in late 2002 that “The project has contributed positively, based on the master plan, to urban development”.

Well, up to a point. Last Friday, The Jakarta Post carried a story headlined “Bridge in Palembang may collapse due to excessive urination”. Not really much more needs to be said, but let’s spell it out. The bridge is sloping. This ‘irregular slant’ had been confirmed by Professor Annas Ali, a highway and bridge expert at the public works office who conducted research on the bridge recently (presumably by standing on it and noticing that he was not standing, as we engineers call it, ‘straight’).

Upon further inspection officials noted that, in the words of the Post, “one of the reasons for the apparent structural deterioration was due to the frequency of people urinating on one of the steel pillars of the bridge, causing it weaken due to the corrosive forces of human urine.” This deterioration can be measured since you can actually feel the bridge ‘resonating’. This was proven by the head of the city’s transportation office, Syaidina Ali, who advised the Post reporter to ”try standing on the Ampera bridge. If the traffic passing on the bridge is heavy, you can feel it moving quite a bit.” Presumably he did not advise standing under the bridge in case a colleague was corrosion testing.

If someone had been, it wasn’t anyone from the highway and bridge department at the Palembang Public Works Office, whose head, Azmi Lakoni, was quoted by the Post as saying that his office had not yet done research on the condition of the bridge. But Mr Lakoni did agree on the urine theory. “The office has not yet done thorough tests on the slant of the bridge,” he said, ”but we are concerned that one of its main support piers has been weakened by urine, as it is a popular spot for locals to relieve themselves.”

This is not the only problem facing the bridge, and it’s another bitter lesson for bridge designers. “Another problem that was pointed out,” the Post report continues, “was that people had stolen pieces of the bridge.” This is always a hazard for bridges, but not uncommon in Indonesia (or Australia, thanks to Taka. As the Post explains: “In 1998, when the country was simultaneously in a state of euphoria and confusion sparked by the reformasi movement, thieves were known to have dismantled some parts of the bridge” by climbing the two towers and removing bits of them. It’s not clear from the report whether they were euphoric or confused when they did this, but one can only hope they were not relieving themselves.

My advice to tourists thinking of visiting the area: Avoid the bridge until this whole problem is sorted. But if you do find yourself in the area you now know of a good rest stop.