Bamandongri and Kharkopar Railway Station was envisioned as large-scaled architectural landmarks in the ever-expanding fabric of the urban sprawl at Ulwe and beyond. With the upcoming Navi Mumbai International Airport (N.M.I.A) at Uwe, the anticipated development of housing, commercial activity, industries, and various other domains, is projected to be one of the largest in 21st century India. The complexes have been designed to provide seamless transfers between connecting nodes and further destinations.

Design Ideology
Theme-based station development ideas was presented for the four stations – Sagarsangam, Targhar, Bamandongri, and Kharkopar respectively. The planning of Bamandongri & Kharkopar railway station has been ideated to accommodate future capacities with a strong emphasis on regional interconnectivity.

A contemporary theme of the geometries of motion has been the inspiration for the architectural expression of the projects. Grand concourses on both sides of the station welcome and guide the users to the ticketing areas and subways that lead to the elevated platform areas. On entering the platform level, the platform roof design based on efficient structural sizing for a 38M span provides natural light and is made up of aluminum standing seam interwoven with polycarbonate. This presents a grand experience to the commuters at this transit hub.

Kharkopar Railway Station has also been designed to be one of the finest transit architecture expressions of Modern India. The location being immediately across the International Airport, the interface of the Sky Train, Metro, Railway Harbor line and public buses have been meticulously planned for the efficient functioning of the multi-modal transit hub. They shall complement the state-of-the-art development of Navi Mumbai International Airport and the allied growth and infrastructure development of various sectors. The stations along the N.U.R corridor will provide a great sense of pride for residents and be a prized possession of CIDCO, Indian Railways and mostly, for the residents of the emerging city.

Structural Specifications
Following are the structural elements we used for Bamandongri and Kharkopar Railway Stations:

• Main frame profile for column – Dia 1200 x25th, top circular member – CHS 356X12thk
• Secondary frame – CHS 356X12thk, SHS 300, fabricated box from ISMC300

Uniqueness
The Unique things about the structure are as follows

• Parabolic pipe arrangements for roof.
• Color combination of roof sheet and extended arrangement for polycarbonate sheet.
• Fins on both side of elevation

Considering complex geometry, InSteel was entrusted with single point responsibility of Structural design, fabrication , erection, painting and roofing work. The main roof is barrel vault having 32 mtr span at a height of 10 mtrs from ground level. The 1200 dia massive steel column was designed to accommodate three rafters each 354mm dia pipe in a parabolic vault form. The enitre fabrication was carried out using high precision CNC cutting and welding machines, enabling perfect fitment of profiled cut circular hollow sections with each other. The bending of huge arches was a hurculine task but was managed well with experienced team of inhouse engineers and fabricators. The erection of the entire structure was completed in 5 months time using high capacity mobile cranes. The roof geometry formed has two distinctive shapes, side cones being utilised to fix Polycarbonate sheets allowing ample light inside and central petal shapes covered with opaue standing seam aluminum roofing giving entire roof a substance and solidarity.

Raju Jagtap
Managing Director, INSTEEL Engineers Pvt Ltd

Steel Used
The Steel Sections with grades used for the project are:

• Material grade – IS2062 – E250
• Sections – ISMC-75, ISMC-100, ISMC-300, ISMC-400, CHS355.6X12, CHS406X12, PIPE 900X12, PIPE 1200X25, RHS 240X120X6, RHS100X100X5
• PLATE THICKNESS – 6 – 50MM

For Bamandongri station 2500MT of steel and for Kharkopar station approx. 1500MT of steel was used

Connection design was used for member to member, for easy erection process. Whereas Crain 25MT, 50MT and 100MT was used along with H frame scaffolding, fabricated Derick as well as Mechanical and electrical winch was used.

Encounters
The major challenges we faced during fabrication and erection of structural steel:

• 36MTR circular truss erection at more than 15mtr height.
• Erection of parabolic truss at zero – zero level.
• To overcome this issues, hi-tech equipment and skilled manpower were used.

The team followed their own specialized HSE program. The safety engineers’ team was having very good experience for fabrication and erection of such structures. Everyday mockup and safety drills for each workman with proper monitoring systems was followed.

Welding processes used for this project are:

• SMAW – Shielded metal arc welding
• MIG –metal inert gas welding (co2)
• SAW – Submerged arc welding

For Bamandongri station total manpower was around 52 (Average) and Manhours were 104832 approx.

And for Kharkopar station total manpower was around 45 (Average) and Manhours were 75600 approx.

Features
The designs are based on efficient structural design, low maintenance structures, naturally lit and ventilated public areas, efficient circulation, and a grand experience to the commuters at the transit hub. Building material: Along with the desired design performances, Life Cycle Analysis methodology has been used for selecting building materials. The primary structure is designed in M40 grade of RCC and the multi cell polycarbonate sheets are used for sky lights on roofing. These lightweight low maintenance and durable sheets enabled the designers to reduce the dead load on the structure and bring in adequate diffused daylight on the platforms.

Building materials like material for flooring, cladding, etc. all have been chosen based on their high rating on the life cycle analysis performance. Services: The total connected load of the project is 440 kW. Provision for solar lighting system of is provided on Aluminum standing seam roof based on clip-on system. 75,000 liters of water per season is collected via rainwater harvesting system installed at site and is used for flushing and cleaning.

This project has been a unique combination of the highly technical aspects to be combined with multi modal transit hub planning along with peak hour crowd management while designing an iconic structure that shall become identity of the said locality.

Fact File

Client: CIDCO
Architect: Hiten Sethi and Associates
Structural Consultant: INSTEEL Engineers Pvt Ltd
Fabricator: INSTEEL Engineers Pvt Ltd
Steel Supplier: Jindal Steel, SAIL, Tata Steel & Apollo
Status: Completed