How technology helped locate car that slid off Likoni ferry - Oguna

Government Spokesman Cyrus Oguna has said that they employed advanced strategies and technology to locate the position of the sunken vehicle in the Indian Ocean.

Mariam Kighenda and her four-year-old daughter Amanda Mutheu drowned at the Likoni Channel on September 29 after their saloon car slipped off the ferry.

The wrecked vehicle was spotted at 58 metres deep on Wednesday by the foreign divers, who flew into the country after efforts by the Kenya Navy to locate the vehicle and the bodies of the victims hit a snag.

Oguna, however, said they were yet to confirm if the car still had occupants inside.

"We can confirm to all Kenyans that the car inside the ocean is the one that plunged, but we cannot confirm if the bodies are inside we will only do that tomorrow after retrieving it," he said.

Oguna in a phone call interview with the Star attributed the success of locating the wrecked car to advanced technology.

"Before Wednesday we used equipment that saw objects at the sea bed in two dimension, such as width and height but no thickness," he said.

NARROW DOWN THE SEARCH AREA

On Tuesday evening, the diving team scaled down the use of the human interface and scaled up to the use of the technology.

They modified their boats to fit the latest technology acquired for the operation.

The rescue team on Wednesday narrowed the search area by mapping four locations, where they suspected the vehicle and bodies could be lying.

"The mapping was possible because of echo sounders equipment which is used to determine the depth of water and detect objects in the sea," Oguna said.

The echo sounders work by identifying signs of disturbance, indicating the presence of a foreign object not common in water.

The area with green and red markers is where the car was spotted, 58 meters depth seabed.
Image: Weldon Kipkemoi

According to Marine  Discovery, the ocean is fairly transparent to sound and opaque to all other sources of radiation.

Swedish scuba diver Volker Bassen last week Friday dashed the hopes of the family of 35-year-old Mariam after failing to locate and retrieve her body and that of her four-year-old daughter, Amanda Mutheu from the Indian Ocean.

Bassen said there is zero visibility in the water making the operation daunting.

MULTIBEAM SYSTEM

After the narrowed search, the multi-beam system was deployed. It uses sound propagation to search for objects underwater.

"After inventory checks by government agencies, we deployed a multi-beam system that is able to look at the sea bed in three dimensions (3D)," Oguna said.

It is among the most effective tool for monitoring foreign objects at the sea bed because of it's sound's ability to propagate long distances in the water.

The multi-beam system is very sensitive and can measure features on the ocean bottom smaller than one centimetre (less than 1/2 an inch).

It has a high resolution and when it detects the object it shows the real image.

"The equipment imagery is high.so we could tell it was a car. It sees the length, width and thickness," Oguna said.

They used advanced underwater cameras and the ferry station CCTV to identify the plates later on.

The divers are afterwards deployed in the refined area where the car is spotted.

Oguna said they will know on Thursday whether the car has occupants,

Eight divers from South Africa on Tuesday joined the Kenya Navy to retrieve the bodies.

The family of Mariam contracted five divers from SubSeas Services, a commercial diving company operating in South Africa. The government brought in three others from South Africa.

Last week, Mombasa Governor Hassan Joho donated Sh2 million to the family towards helping hire professional divers to help in retrieving the bodies.

In the past week, weather challenges have hampered the operation after heavy rains pounded the region. Visibility was also cited as a major challenge along the channel.

An unknown number of Indian Naval forces also volunteered to help their Kenyan counterparts. The operation was on Monday boosted after the government procured high-tech equipment.

Kenya Ferry Services chairman Dan Mwazo told the press on Monday that the government had procured more equipment that will assist the new team in the retrieval mission.