THE tragic launch accident in Padma, the salvage team's incessant efforts, mourning of grief-stricken bereft relations of the victims, impel me to participate in the ongoing task of locating the wreck with some humble advice, if it is worth accepting by the team. As an officer of the concerned department of BIWTA, I participated in and guided many salvage operations in our inland rivers (including the Padma, Jamuna and Meghna).
There are some guiding parameters that need to be followed for earmarking the area for sweeping, scanning, sounding, etc. to locate the wreck. The following information is required for organising the search:
(1) Was the launch making a crossing? I guess it was doing so from Shibchar towards Lohajang;
(2) Did the sinking take place in the main channel, or before or after passing across the main channel? If before, then the wreck is supposed to be pushed aside towards the right bank (Shibchar bank); if after, then towards the left bank (Lohajang side). The wreck generally cannot remain in the main channel. Hydraulic character of water pushes aside anything heavier than itself and failing to flow with it at the same speed;
(3) In the area concerned, the highest water velocity at average depth in the deepest channel of the river is around 18 km/hr (about 9.5 knots); at other spots it is 5.5 km/hr to 10.5 km/hr (3.1 knots to 5.8 knots). This happens in July-August. The stronger the current the more forceful is the push;
(4) So the wreck will be within about 10 kms downstream if on the Lohajang-Mawa side because it is the deeper side with stronger current, and within about 5 kms downstream if on the opposite shallow side, from the spot of sinking
(5) If the wreck is lying on the side, there is chance of finding eddies and vortexes on the water surface. If the wreck is fully capsized, the surface water there may be smooth.
I would, therefore, advise the team to concentrate their search more on the sides of the river. The suggestion, however, does not guarantee finding the wreck.
The writer is former director of BIWTA.