Nov 2016 Mazagon Dock Limited Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagon Dock, Mumbai C [Type the document subtitle] Final Report WAPCOS Limited Pune Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai TABLE OF CONTENTS No. PARTICULARS Pg. No. Executive Summary i Chapter 1 : Introduction 1.0 Introduction 1 1.1 Brief History 3 1.2 Scope of Work 5 1.2.1 Objective of the Study 5 1.3 Organisation of the Report 5 Chapter 2 : Site Condition 2.1 Site Condition 6 2.2 Bathymetry 6 2.3 Wind 7 2.3.1 Offshore Wind Data 7 2.3.2 Inshore Wind Data 7 2.4 Tides 8 2.5 Current 8 2.6 Wave 9 2.7 Relative Humidity 9 2.8 Temperature and Salinity 9 2.9 Rainfall 10 2.10 Bed and Water Samples 10 Chapter 3 : Field Survey and Investigation 3.1 General 11 3.2 Bathymetry 11 3.3 Field Data Collection for Monsoon Season 12 3.3.1 Tides 12 3.3.2 Current 14 Final Report Page i Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai 3.3.3 Water Sample 14 3.4 Field Data Collection for Non-Monsoon Season 15 3.4.1 Tides 15 3.4.2 Current 16 3.4.3 Water Sample 16 3.4.4 Bed Sample 16 Comparison of Monsoon with Non-Monsoon 3.5 17 Observations 3.5.1 Tide 17 3.5.2 Currents 17 3.6 Geotechnical Investigation 19 3.7 Laboratory Test 21 3.8 Test on Soil Samples 22 3.9 Test on Rock Samples 22 3.10 Test on Water Samples 22 3.11 Exploration Program 22 3.12 Subsurface Profile 23 Chapter 4 : Mathematical Model Studies carried out at CWPRS, Pune 4.1 General 25 Mathematical Model Studies for Hydrodynamics 4.2 25 and Siltation 4.2.1 Recommendations by CWPRS 26 Mathematical Model Studies for Wave Transformation and Assessment of Wave 4.3 27 Condition along Proposed Extension of Navigational Channel 4.3.1 Recommendations by CWPRS 28 Desk Studies for Design of Proposed Extension of 4.4 29 Navigational Channel 4.4.1 Recommendations by CWPRS 29 Mathematical Model Studies to Assess Feasibility 4.5 of Flood Dumping Ground for Disposal of Dredged 30 Material 4.5.1 Recommendations by CWPRS 31 Final Report Page ii Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai 4.6 Seismic Sub Bottom Profile Studies 31 4.6.1 Conclusions made by CWPRS 32 Chapter 5 : Budgetary Cost 5.1 Basis of Cost Estimates 33 5.1.1 Dredgers 33 5.1.2 Methodology 34 5.1.3 Disposal of Dredged Material 34 5.1.4 Maintenance Dredging 34 5.2 Basis of Cost Estimates 34 5.3 Calculation of Cost Estimate 35 Chapter 6 : Concluding Remarks & Recommendations Final Report Page iii Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai LIST OF FIGURES No. PARTICULARS Pg. No. Proposed Layouts of Navigational Channel from Figure A iv MDL up to OCT Berth (Option I and Option II) Proposed Layout of Navigational Channel from Figure B iv MDL to OCT Berth – Option III Location Plan of Mazgaon Dock Shipyard at Figure 1.1 1 Mumbai Figure 1.2 Depth Requirement Proposed by MDL 4 Proposed Alignment of Navigational Channel from Figure 1.3 4 MDL to OCT Bathymetry survey carried out for studies (Year Figure 2.1 7 2015) Bathymetry Survey carried out for Studies (Year Figure 3.1 12 2015) Tide graph at MbPT, Ambuja, Vashi and Rewas Figure 3.2 13 during springs Tide graph at BPX- MbPT, Ambuja Jetty, Vashi Figure 3.3 14 Bridge and Rewas Jetty during springs Figure 3.4 Locations of Marine Boreholes (BH-1 to BH-08) 15 Figure 3.5 Locations of Marine Boreholes (BH-1 to BH-08) 20 The final layout confirmed by CWPRS through Figure 4.1 27 hydrodynamic and siltation studies Figure 6.1 Final layout recommended by CWPRS 36 Figure 6.2 Locations of dumping sites off Mumbai harbour 38 Final Report Page i Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai LIST OF TABLES No. PARTICULARS Pg. No. Table 2.1 Tidal Levels 8 Tidal ranges at MbPT, Ambuja, Vashi and Rewas Table 3.1 13 Locations Comparison of Tidal ranges during non-monsoon Table 3.2 17 and monsoon Period Comparison of Ebb current during non-monsoon & Table 3.3 17 monsoon period at location C1 Comparison of Flood current during non-monsoon Table 3.4 18 and monsoon period at location C1 Comparison of Ebb current during non-monsoon & Table 3.5 18 monsoon period at location C2 Comparison of Flood current during non-monsoon Table 3.6 18 & monsoon period at location C2 Comparison of Ebb current during non-monsoon & Table 3.7 19 monsoon period at location C3 Comparison of Flood current during non-monsoon Table 3.8 19 and monsoon period at location C3 Summary of Co-Ordinates and Depth of Bore Table 3.9 23 Holes Table 5.1 Cost Estimate for Capital Dredging 35 Final Report Page i Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai EXECUTIVE SUMMARY Mazagon Dock Shipbuilders Limited (MDL) is a premier leading warship building and offshore fabrication yard in India under Ministry of Defence, Government of India with ISO 9001:2008 certificate. The yard is currently engaged in prestigious projects both for Indian Navy and for export market. Also, company’s present portfolio of designs spans a wide range of products for both domestic and overseas clients. The MDL is situated on the leeside of Salsette/Mumbai Island on the west coast of India in the state of Maharashtra as shown in the fig. The location of MDL is at Latitude 18° 57’ 58” N and Longitude 72° 51’ 00” E in the Mumbai harbour area. Presently, MDL is building several frontline warships for the Indian Navy. The ships being constructed at MDL are required to be taken out of MDL area, for sea trials, to the open ocean and also towards the Naval Dock (ND) for fitting of weapon sensors. Since sufficient depths are not available in front of their waterfront and existing channel up to Offshore Container Terminal (OCT) of Mumbai Port Trust (MbPT), MDL is now dependent on the tidal window for their activities. The water depth available in these stretches is about 1.5 m to 2.0 m below chart datum (CD) and 6.0 m to 6.5 m during a tide of 4.5m. The maximum draft of fully fitted warships proposed to be built at MDL would be about 7.2m. Final Report Page i Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai In view of limited depths available near the MDL waterfront even during high tide level prevailing in Mumbai harbour, MDL intends to create a well demarcated navigational channel from MDL waterfront up to OCT, Mumbai with sufficient depth for smooth plying. In this regard, MDL has approached WAPCOS Ltd and CWPRS to undertake various studies for deepening and extension of existing navigational channel from northern waterfront of MDL to OCT MbPT berth. MDL entrusted CWPRS to carry out mathematical model studies to find out the feasibility of deepened / new channel from their waterfront to OCT berth. In order to carry out the model studies field data pertaining to various hydrographic and oceanographic parameters were required and subsequently MDL has appointed M/s WAPCOS Limited to carry out field data collections (tides, currents, water samples, bed samples and geotechnical investigation) and to prepare Project feasibility report based on the model studies carried out by CWPRS along with quantum of capital dredging and cost estimate of the project. Accordingly, field data were collected and the reports on Non monsoon season data and Monsoon season data collections were submitted to MDL on June and November 2015 respectively. These field data along with past dredging data in the existing channel formed the inputs for the following studies carried out at CWPRS, Pune. 1. Mathematical model studies for hydrodynamics and siltation for the proposed extension of navigational channel. 2. Wave transformation studies to determine wave conditions. 3. Dispersion study to assess feasibility of flood dumping ground for disposal of dredged material. 4. Desk studies for design of proposed extension of navigational channel. 5. Sub–bottom seismic profiling of proposed navigational channel area. The reports of the same were submitted to WAPCOS through MDL. Initially, two alternative alignments of navigational channel were proposed by MDL (Fig A). But based on preliminary studies, it revealed that flow field is not suitable with the alignment proposed, which may create problem for ship manoeuvring and increase siltation. Hence, third alignment based on study of prevailing flow field as Final Report Page ii Feasibility Studies for the Proposed Extension of Navigational Channel at Mazagaon Dock, Mumbai Option-III was considered for further studies by CWPRS as shown in Fig B. The flow field observed being parallel along the navigational channel extension (Option-III), irrespective of phase of tide; it was considered for deciding the cross section of channel based on ship navigational studies. The cross section as well as the alignment finalised through ship navigation studies indicated that uniform channel width of 110 m is required in the straight part of the navigational channel and width at the bend of the channel is 125 m.