The Pandrol VIPA DRS systems is a Pandrol e-Clip baseplate is mounted on a studded natural rubber pad which provides resilience. This can be tuned, within limits, for axle loads and stiffness requirements. The origins of the Pandrol VIPA DRS system go back to installations in Singapore and Hong Kong in the 1980’s. Today the evolved versions of VIPA DRS are being installed, or have been installed in major cities such as Bangkok, Chennai, Delhi, Dubai, Hong Kong, Istanbul, Kolkata, Kuala Lumpur, Sao Paulo, Seoul and Singapore.
VIPA DRS systems are also installed on mainline slab applications and steel bridges with axle loads up to 22.5 tonnes.
The Pandrol VIPA DRS System has been proven over 3 decades to be an outstanding solution for metro, express rail and main line applications. The majority of installations have been in LRT and Metro but applications exist on Steel Bridges and Main Line (Passenger Freight). The Hong Kong airport express line features a variant of VIPA DRS in the turnouts, with speeds up to 130 km/h. Typical stiffness 20 kN/mm for CEN CAT B but can be lower or higher within limits, consult us for specific requirements.
The combination of performance and economic design in the VIPA DRS system has been a key factor in its success.
The Pandrol VIPA DRS System os an indirect system. It provides the advantages of an indirect rail fastening system, distributing the vertical deflections between the rail pad/clips and the baseplate pad/compression springs, and separating the functions of the anchorage and rail fastening.
As with all Pandrol VIPA systems, VIPA DRS exhibits a high level of electrical insulation through 2 levels of insulation, the rail being insulated from the baseplate and the baseplate being insulated from the concrete slab.
For dealing with the track structure interaction between the rail and the structure, low toe load and/or zero longitudinal restraint (ZLR) fastening options are available.
The coil springs and baseplate pad absorb most of the vertical deflections and also play a part in countering the effects of end rotation where simply supported beams form part viaduct structures.
Vertical and lateral adjustment is provided for construction/maintenance requirements. Vertical adjustment typically up to 20 mm and lateral adjustment through lockable eccentric bushes (+/- 3 mm per rail and +/- 2 mm by differential side post insulators) total +/- 5 mm per rail.
Pandrol VIPA DRS is ideally suited for LRT/Metro.
The indirect system provides sufficient adjustment, a high level of electrical resistance, and adequate resilience for plain line and turnouts.
The system conforms to EN 13481-5:2012 for CAT B Tracks and has been widely adopted in a number of major metro projects since 2007, though the system originates from installation in Hong Kong and Singapore in the 1980’s.
Many LRT/Metro projects adopt DC power systems and this requires the rail fastening system to mitigate the potential harmful effects of stray current. VIPA DRS exhibits a high level of electrical insulation through 2 levels of insulation, the rail being insulated from the baseplate and the baseplate being insulated from the concrete slab.
LRT/Metro projects are often subject to environmental requirements which limit the levels of noise that can be permitted directly from the tracks or as a result of secondary noise in buildings along the route.
Pandrol have developed retrofit, low stiffness solutions that exactly match the footprint of VIPA DRS making it possible to change the acoustic behaviour of the fastening system and providing future proofing for unforeseen or future building developments that may have an impact on the environmental needs. You can find more information about the Vanguard retrofit solution here.
For top down construction the VIPA DRS baseplates can be installed using dummy construction plates or using a sacrificial construction plate which forms part of the assembly.
In case of bottom up construction, splayed anchor studs would be replaced by anchor bolts suitable for drill and grout construction techniques.
The VIPA DRS System is suitable for use on non-ballasted bridges.
For such applications the splayed anchor bolts would be replaced by alternative anchor fixing to suit the method of construction and application, whether it be steel beam or concrete slab.
For dealing with the track structure interaction between the rail and the structure, low toe load and/or zero longitudinal restraint (ZLR) fastening options are available. Depending on the length and type of bridge, there may be opportunities to use ZLR fastenings throughout or through parts of the bridge and avoid the use of rail expansion joints. Where rail expansion joints are installed the ZLR fastening can be used to separate the location of the rail expansion joint and the structural expansion joint avoiding the maintenance risk of those 2 features being at the same location.
At the beginning of any project we work closely to determine the most suitable product for the operating and environmental conditions. Pandrol VIPA DRS is suitable for use on some Main Line (Passenger Freight) projects subject to the operating parameters which would have to be reviewed.