Challenges of Transportation of Coal for Rampal Power Plant

The 2X660 MW Rampal Power Plant of  Bangladesh-India Friendship Coal Power Company (BIFCPCL) would require using  13,000MT of coal per day. The entire quantity would be imported either from Australia or Indonesia and would be transported by barges through Possur channel to power plant jetty. The plant would also require limestone as feedstock for sulfur reduction plant known as FGD.  About 1,500 MT fly ash recovered from plant  will also be transported daily from the plant through river route to nearby cement plants. The plant is ideally located (maintaining more than permissible distance from tip of Sundarbans) as existing river channel of 131km developed by Mongla Port will be available for navigation of the barges/ships. Only   a stretch of 13 km upstream up to the power station will require occasional dredging. This write-up discusses the transportation challenge from the Bay of Bengal to power plant over  a distance of 145km. The following factors will have significant contribution for coal logistic in the channel.

·         Siltation in Possur River

·         Siltation at outer bar

·         Transshipment of coal from seafaring vessel to smaller barges 

·         Seasonal weather constraint 

·         Unloading at Plant jetty

·         Siltation and dredging for maintaining navigability

Till early 90’s no dredging was required in Possur for ship movement barring few maintenance dredging in a small scale. But due to multiple problems, the siltation in river Possur kept on increasing. The following few points are major reasons for increase siltation.

Polder design adopted by BWDB to arrest flood in south of Bangladesh resulted in high siltation in river in a long run. The surrounding area in Rampal and Mongla, use of river water for fish cultivation resulted in less tidal flow during low tide causing more silt deposit. .The rivers of western part of Southern Bangladesh (Sibsa, Possur, Madhumati) has lesser flow of upstream water compared to rivers flowing in eastern part (Baleswar, Kacha, Tetulia).

 Mongla Port Authority undertook capital dredging project in 1995, in 2004 and in 2013 in few patches of 131 KM channel. In each of this capital dredging nearly 3.5million cubic meter of silt dredged so that draft in Possur channel maintained a draft of 5.5M CD (Chart datum). This means that 7.5Meter DWT ship or cargo with 20,000MT can come through channel till Port jetty. It is important to note that cargo movement is done during high tide to have 2-2.5M cushion of water level. The available water depth in the entire channel till jetty shown in below 2 charts.

Rampal plant is located 13KM upstream of Port. To make this 13 KM stretch for 5.5M CD level, GOB has planned to undertake a capital dredging project , implementation date of which will coincide with plant operation date. In various parts of river for a length of 9.6KM shall be dredged and estimated quantity will be around 4million cubic meter. Both side of the river of 13KM stretch either have villages or land acquired by private industries, thus making it difficult to dump spoil material. During feasibility study, pockets are identified for filling as shown in map below. The second biggest challenge is maintenance dredging which is required every year due to high sedimentation rate which is in the range of 50-60% of capital dredging volume. This backfilling rate depends on sediment transport in the river during monsoon by upstream flood events and tidal pumping from downstream in dry period.

Siltation at outer bar and required dredging - In outer bar area near Fairway Buoy due to a ship wreck the navigation channel has shirnked due to siltation and now 6.5M CD available in channel which restricts cargo movement of bigger size (less than 25,00MT). A proposal for increase of draft to 8.5M CD with an estimated dredging quantity of 10 million cubic m. has been initiated by Mongla Port Authority. Once the dredging is completed, Rampal project can bring 45,000MT cargo till Harbaria anchorage.

Anchorage Point Statistics

Transshipment of coal in from seafaring vessel to smaller cargo-As things stands today coal transportation from source to plant requires literage at any intermediate point. Rampal project will engage agency for transporting coal from mine mouth to plant jetty and payment will be done on tonnage basis irrespective of transport modalities. However studies carried out to check various options for large coal carrying cargo (75,000T to 1,20,000T) at various anchorage points or at nearby deep sea port. Literage in Fairway buoy does not permit throughout year due to rough weather. Hence options are wide open for transshipment in deep sea port such as Paradip, Dhamra, Haldia in India or Kutubdia anchorage or Paira port (only around 2022 as per plan). If Panamax or Capesize vessel  carrying coal (80,000T-1,20,000T) can berth in deep-sea port where coal terminal is available with loading/unloading facility, then one covered mid-size cargo having 10,000-15,000T capacity can straightway come to plant jetty, thus avoiding literage in Akram point or Harbaria in Possur channel. Option of bringing ship with 45,000T coal straight to Harbaria anchorage also possible if the outer bar dredging project for 8.5CD is approved and funded by GOB.  After Harbaria the Possur channel has CD of 5.5M. Hence literage required to be done at Harbaria for 45,000T vessel carrying coal. Transshipper will be used to unload and load to smaller barges.

Seasonal weather constraint -It is well known fact entire coastal belt of Bangladesh is prone to cyclonic weather and extended monsoon season. So it is natural for Rampal authority to keep a coal stock as a contingency measure. Considering coal to come from faraway foreign land through a long route, the project authority has planned to have coal stackyard for 3 months. Coal based power station, being a base load power station, top priority is given for continuous running. During flow of northern wind, the coastal Bay of Bengal and river channel are more calm (compared to period when southern wind flows to Bangladesh) and uninterrupted movement of barges/ships and possibility of literage at Fairway Buoy is ensured.

Unloading at Plant jetty -   Unloading of coal will be done in a jetty (550M long) on river Possur considering berthing of 2barges (10 to 15 thousand tons of coal) and two smaller size barge for ash transportation. Pipe conveyor of 2000MT/Hour will be installed to carry coal to bunker in main plant area. Alternatively coal can be transported to nearby covered stackyard through transfer point.

Debadatta Ray;

Assistant General Manger
Bangladesh India Friendship Power Co. Ltd