The feasibility study,technical assesment and site investigation is conducted and compiled by the proponent himself with the following information :
Company Name: PT.Sarana Karya Anugerah Lematang
Company Address:
AXA Tower Building,Floor 45th
Jl.Prof.Dr.Satrio,Kav.18—Jakar
Jakarta,12940—INDONESIA
Office Complex PTC I/10,Palembang
Person in Charge: Agussalim Igarashi
Position: President Director
Project Location: Sungai Lematang,Lahat and Muara Enim District
Business Fields: Energy,Transportation,Reclamation EPC Engineering Services
Part of the studies also to analysis the deliberate ships dimensions with the following particular tug and ships barge specification :
And routability production rate limitations of the river for coal barging due to :
- River Sedimentation
- Water Depth Availability
- Width and Angle of the Bends
- Flow Velocity of the River
By identify and examined major aspect above,the objective of the lematang river – musi river for coal barging transportation become feasible.
- River Sedimentation
Sedimentation rate in the Upstream of Lematang River to the Downstream of Muara Lematang at Musi River being identify along 235 km lenght with the following coordinate :
Start point / Rantau Bayur,Tebing Abang
- Latitude : S 3 – 23 – 10.1
- Longitude : E 104 – 04 – 18.1
Finish point / Merapi,Telatang
- Latitude : S 3 – 39 – 44.0
- Longitude : E 103 – 45 – 45.0
With total of sedimentation volume to be dredging : 12,457,680 m3
- Water Depth Availability
Water availability is estimated by low flow analysis is to estimate the water availability in the river, which is known as dependable flow. Water availability analysis requires reliable daily or monthly discharge data in excess of 10 years and for better accuracy, longer data is needed. Data should be obtained directly from measurements at Automatic Water Level Recorder (AWLR) stations in rivers in the vicinity or directly flowing pass the study site.
Refer to the three (3) AWLR station river,water potential discharges calculation up to year 2035 as below follows :
- Lebak Budi Sta No : 01-074-00-27 : 101,28 m³/sec (AVERAGE)
Lebak Budi Sta is located southwest of the city Muara Enim in Lebak Budi village,Merapi district, Lahat regency and is geographically located at S 03° 46’ 53” and E 103° 38’ 31”.
- Pinang Belarik Sta No.01-074-00-40 : 159,00 m³/sec (AVERAGE)
Pinang Belarik Sta is located north of the city Muara Enim in Pinang Belarik, Kikim
district, Lahat regency and is geographically located at S 03° 33’ 39” and E 103° 45’ 32”.
- Sungai Rotan Sta No.01-074-00-02 : 378,00 m³/sec (AVERAGE)
Sungai Rotan Sta is located north of the city Prabumulih in Sungai Rotan village,
Muara Enim regency and is geographically located at S 03° 03’ 43” and E 104° 09’ 59”.
And or from the three (3) AWLR river station above water availability analysis mean level average show in the level of 159 m³/sec discharge capacity and or the resulted from three (3) AWLR river station showing 28% higher than formula computation results.
Refer to the three (3) AWLR station river,water potential discharges calculation up to year 2035 as below follows :
From the three (3) AWLR station aboved te flow duration curve starts at 750 m³/sec then drops quickly until probability level of 10%, then flattens until 95% and finally drops down at 100%.
- Height,Width and Angle of the Bends
The Lematang River capacity is limited by bend radii and water depth due to sedimentation during the dry season especially to achieved the minimum water level surface along 235 km lenght of river navigation channel.
There are 44 superficially spots being identify required to be dredges to overcome the current limitation above include 18 bridge point location that need to be dredge also,for the river bed and the width of the river (existingly) to achieved the best practise of safety minimum elevation water surface for barge navigation.
- Section 1, sedimentation volume : 811,138 m³
- Section 2, sedimentation volume : 391,688 m³
- Bridges in Section 1 & 2, sedimentation volume : 435,528 m³
Total sedimentation volume that need to be dredge include swell factor and sf : 2,103,647 m³
- Flow Velocity of the River
HEC-RAS is capable of performing water surface profile calculations for steady gradually varied flow for a full network of natural and constructed channels. The system can handle a full network of channels, a dendritic system, or a single river reach. The steady flow component is capable of modeling subcritical, supercritical, and mixed flow regime water surface profiles. The basic computational procedure is based on the solution of the one dimensional energy equation. Energy losses are evaluated by friction (Manning’s equation) and contraction/expansion (coefficient multiplied by the change in velocity head). The momentum equation is utilized in situations where the water surface profile is rapidly varied. These situations include mixed flow regime calculations (i.e. hydraulic jumps), hydraulics of bridges, and evaluating profiles at river confluences (stream junctions).
HEC-RAS tests the applicability of subdivision of roughness within the main channel portion of a cross section, and the program will compute a single composite n value for the entire main channel. From the modelling in the program include the analysis and results portion from 3 (three) AWLR-Automatic Water Level Recording River Station in the Lematang River,The program could determines and calculated the potential water flow velocity in the Lematang River :
Where
V : flow velocity (km/hour)
H : height difference between the remotest part of the watershed and the point of
observation/calculation (km)
L : river length (km)
V = 72 (1,75/35)⁰ֹ˙⁶ = 11,93 km/hour
Associated study and investigation has been cater for the following 4 major aspects aboved, and we could then identify and justify the total dredging volume for the :
Dredging work volumes for Initial/Post Dredging for 235 km lenght :
2,103,647 + 9,092,640 + 3,365,040 = 14,561,327 m³.
Dredging work volume for Maintenance Dredging by Yearly basis for 235 km lenght: 723,908 + 54,313 m3/year = 778,221 m³/year.
The channel canalization studies with dredging works of the Upstream Lematang River to Downstream Lematang River in the Muara Lematang/Rotan River – Musi River for 235 km lenght design for sailing purposed of coal barge transportation design of 5,000 DWT.
With assumption from 28 million of coal design capacity to be transport thru to the Lematang river x 60% AF = 16,800,000 tones/year for 5 year 1st round up channel operation and after 5 years operation increased to 22,100,000 and forward to 5 years operation for 28,000,000 tones/year.
Traffic at the river 16,800,000 : 136 Trip : 2,64 Days/Trip : 5,000 Tones/Trip : 12 Barge/Day and or each barge distance to other barges approximately 20 km along channel river navigation 235 km from Upstream Lematang River to Downstream Muara Lematang – Musi River which is this very safe and reliable.
5. Schedules of Project and Work Stage
The construction dredging production schedule shown as below:
The dredging production schedule identifying the in situ volumes of material targeted for removal for each 4-week period, presented in below :
This table is based on the study and concept equipment dredge selected issued to the dredging study for budget and planning purposes with the following assumption (q) capacity and fleet combination :
- Mechanical bucket/backhoe dredge : 6,000 m³/day x 6 Unit = 36,000 m³/day
- Hydraulic suction cutter head dredge : 8,000 m³/day x 3 Unit = 24,000 m³/day
- Barges sediment transporation and storages : 36 Unit
- Working location/dredge unit set : 3 work location/day
- 1 mechanical bucket/backhoe dredge
- 1 unit of hydraulic suction cutter head dredge
12 unit of barges sediment transporation and storages
6. Project Capital Structures
Project Summary
The Lematang River is the major river flowing on the southern border the project site. The river originates from the mountains of Bukit Barisan range about 2,000 to 3,000 m above mean sea level. Lematang River is itself a tributary of the Musi River which flows to the sea at the strait of Bangka. Lematang River has several tributaries, i.e. Air Enim in the south and Air Lintang in the southwest. The tributaries flows pass the forests in the mountains, hills, paddy fields and plantations in the lower plains before joining Musi River.
Coal transportion by river waterways thru lematang river to musi river is generally cheaper per tonne per kilometre than any land mode transportation and or lower energy cost per tonne transported :
The Coal inloading and unloading port terminal will be located into 2 location,1 in desa Merapi for coal inloading facility with design capacity of 3,000 tph and 1 location in Patra Tani coal port terminal for coal unloading/inloading facility (transfer point prior to the MV-monther vessel in bangka strait).
Infrastructure and maintenance costs of the river waterways by barges was lower than for railway transportation method furthermore new track of rail train will be require for new side of land purchased from the local people and therefore as common understanding as to build a new track rail train will be more costly than upgrading the existing track and therefore railway is limited by the land geological structure (swamp area etc).
The average construction cost is US$ 338,445/km in 1972 and if we assume the inflation in Indonesia 5%/year, it is estimates the cost is approximately higher 200% in 2011 which is US$ 1,06 Million per Kilometres. The Railroad from Muara Enim to Muara Abab (Barge Loading Point Area) is ±90 Kilometres which cost around US$ 125 Million, including the assumption of 30% miscellaneous cost factor such us environment and community.
With assumption for 28 million tones/year of output production, The total trainset combination as the above concludes that the total capital cost for the overland transportation will be the construction cost for the railroad plus the trainset combination which are US$ 125 and US$ 56 Million respectively, the total of the capital cost approximately US$ 181 Million as table below as following :
Further from the explanation above advantages of transportation by Lematang River :
- Lower transport costs since water transport is commonly cheaper ton/km than any modes of land transport.
- Lower gains on energy costs and emissions.
- Infrastructure (CAPEX) and maintenance costs are possibly efficient than those of rail,road and conveyor.
- Effects to the environment ought to be less than building a new alignment.
Meanwhile there are also some disadvantages :
- The factual distance the coal must be transported by river may be significant caused by the twisting alignment of rivers in South Sumatra.
- The slow speed of transport by river, worsened by the winding alignment would result in more time for transit, compared to land modes of transport. Nevertheless, since coal is non-vulnerable, the cost advantages possibly exceed this issue.
The Lematang river flow velocity 11,93 km/hour and or > (aboved) than design speed of assist tug barge design 5,000 DWT which is 4 Knot and or 7,2 km/hour and with sufficients of water lematang river discharges capacity (Q)114 m³/sec – 159 m³/sec is resulted option to unlock greater potential to expanding the river waterways transportation thru to the Lematang river – Musi river become feasible and reliable which is generally more economic,reliable and safe than any other land transportation mode and also lower energy cost transported.
The cost associated for the Channel Operation of Coal Transportation by Lematang River quoted as below follows :
- Channel Cost (Dredging and Barging Cost) : Rp. 400/ton/km.
- Coal Barge Inloading : US$ 0,92/ton including Stockpile Management and Weigh Bridge At Coal
Terminal – Coal Barge Inloading - Coal Quality Lab Services : US$ 0,1/ton At Coal Terminal – Coal Barge Inloading