The Tanzania Electric Supply Company (Tanesco) says a fault on an underground 132-kilovolt transmission line is behind unreliable power in southern Dar es Salaam, Mwananchi reported. The fault struck at Gongo la Mboto on Tuesday, November 3. It has disrupted supply in Mbagala, Kigamboni, Mkuranga and Kibiti.
Irene Gowelle, Tanesco's director of communications and customer service, briefed reporters on Thursday. She said the fault hit the underground cable that carries power from the Gongo la Mboto station to the Mbagala and Dege substations. Because it came suddenly, the utility could not warn customers in advance. As an emergency measure, Tanesco switched customers to another line to keep power flowing.
That backup line is the problem, according to Zakaria Mgalama, Tanesco's deputy managing director for transmission. He said it has less capacity than the damaged line. As a result, some areas face load cuts when demand peaks, mainly during the day. At night, demand drops and all customers get power back.
Mgalama said technicians are still working on the fault. He said underground lines take longer to repair than overhead ones. Repair time depends on the size and location of the fault. If a cable fails beneath infrastructure such as a railway, crews must first dig it up. "Problems like these have happened before," he said, adding that overhead lines can often be fixed within hours.
If the fault lies at the cable's end joints, Mgalama said, repairs could take between five days and a week. The exact time depends on conditions at the site. Meanwhile, Tanesco is moving some customers to other substations to ease the impact.
Mgalama said the government is building major transmission projects to make supply in southern Dar es Salaam more reliable. They include a 400-kilovolt line from Chalinze to Mkuranga and a 220-kilovolt line from Pugu to Dundani. He said the new lines will add capacity and provide backup routes when other infrastructure fails. Tanesco said it will make an official announcement once repairs are complete and service returns to normal.