The population of Vietnam has grown rapidly in the past 10 years and Hanoi, its capital city, now has around 8 million people. Traffic is extremely heavy in the city: buses operate at an average speed of just 16–18km per hour and air pollution is a major concern. In response, back in 2016 the Hanoi Metropolitan Railway Board appointed Colas Rail, along with Alstom and Thales, as the main contractors for the pilot line of a new metro system.
Hanoi Line 3 will cover 12.5km between Hanoi Station and the town of Nhon to the west of the capital. Of this total distance, 8.5km will be built on a viaduct and 4km in a tunnel. Four of the line’s twelve stations will be underground.
The Hanoi Line 3 design features third rail electrification and 1,435mm double-track European standard type-B rail. The underground section, dug by a tunnel boring machine, consists of two single tubes. The line will operate at a speed of up to 80km per hour.
Pandrol was asked to supply three key elements to support the infrastructure for Hanoi Line 3:
- The third rail system, taking into consideration rolling stock, track works, power supply and civil works interfaces
- The rail fastening system, with a particular emphasis on noise and vibration mitigation
- Aluminothermic welding kits.
For the third rail system, Pandrol supplied the RAS co-extruded conductor rail system. Developed and supplied by Railtech Alu Singen, a joint venture between Pandrol and Constellium Group, the aluminium/stainless steel conductor rail is made using co-extrusion technology that delivers high levels of reliability and stability. With no delamination and no need to control the thickness of stainless steel, its expected lifetime is 20% higher than other composite rail technology.
Anchoring solutions were selected from a wide range of standard Pandrol products. Protection board brackets are used to support the protection board at a distance above the steel contact rail. Designed with outstanding electrical properties, insulating covers provide protection for employees working near the track. The Pandrol team used its extensive track expertise to carry out a full analysis of layout to ensure train power continuity and is providing technical service and support throughout the installation and commissioning phases.
Pandol’s Single Resilient (SRS) fastening system’s full insulation and excellent stray current protection make it an ideal solution for Hanoi Line 3. Incorporating e-Clip assembly, the non-bonded, low-profile system consists of a cast baseplate and a resilient pad. Vertically serrated holes allow for lateral adjustment and components can be easily changed to meet loading requirements. Sizes, thicknesses and materials have been tailored to suit the application.
Pandrol’s final contribution to the project has been PLA one-shot crucible aluminothermic welding kits. The aluminothermic welding process involves molten steel produced through the reaction of iron oxide and aluminium being cast at a temperature exceeding 3,500°F into refractory moulds designed to suit the rails to be welded. The one-shot crucible is made from bonded refractory sand and does not require any preparation. For Hanoi Line 3, the aluminothermic welding kit was provided with a weld portion and mould designed to suit the requirements of the specific rail profile.
The Pandrol team assisted Colas with on-site training in the use of the technology, including instruction and demonstration of products and equipment, and welder certification.
The first phase of the Hanoi Line 3 project, the elevated part of the line, is on track to open to the public in 2021. With major advantages over existing transport systems in terms of cost, environmental-friendliness, speed and ease, Hanoi Line 3 looks set to quickly change lives in the city for the better. Once in service, it will carry 8,600 people an hour in each direction.
