Delhi Metro enhances safety measures with Wheel Flange Lubrication System

In a significant move to bolster safety and efficiency across its network, Delhi Metro Rail Corporation Limited (DMRC) has issued a Letter of Acceptance (LoA) to M/s REBS Lubrication India Pvt. Ltd. for the installation of a state-of-the-art wheel flange lubrication system. This development comes as part of DMRC’s ongoing commitment to ensuring the smooth operation of Line-06, also known as the Violet Line.

  • Tender Reference Number: ORW-1467
  • Name of Work: Design, supply, installation, testing and commissioning of on-board oil/grease based wheel flange lubrication system in 44 nos. of train sets of Line-06 in Delhi Metro Rail Corporation Ltd. along with DLP of 2 years (inclusive of all consumables).
  • Awarded Value: INR 4,14,92,179.52/-
  • Contract Period: 01 Year

In September 2023, the DMRC has invited a tender for Tender Number: ORW-1467


Line-6: Violet Line (one of the lines constructed and operated by DMRC) is passing through one of the most densely populated sections of Delhi connecting Raja Nahar Singh (Ballabhgarh) Faridabad (Haryana) to Kashmiri Gate in Delhi.

Line-6 has been commissioned in 7 stages, with the 1st stage being commissioned since 3rd October, 2010 and recent stage being commissioned since 19 th November, 2018. The salient features of the Line 6 –Violet Line are indicated below:



Total Number of Stations

34 (11 Underground + 23 Elevated)

Length of the Line

46.59 Kms

Total Train sets serving the Line

44 ( 6 Cars formation)

Presently Forty –four (44) train sets operates between Kashmere Gate to Raja Nahar Singh (Ballabhgarh) i.e. Line-6 Violet Line. Forty Four (44) Train sets operating on Line-6 Violet Line have been manufactured by M/s MRMB/BR.

Scope of Works:

Contractor shall execute complete Design, Supply, Installation, Testing and Commissioning of Wheel Flange Lubrication system in 44 nos. of train sets of Line-06 (Violet Line) in Delhi Metro Rail Corporation Ltd. The contractor shall comply with the technical specification of the wheel flange lubrication system as specified in Attachment 1 of Employer’s Requirement.

Contractor shall submit the detailed design complying to the technical specification and relevant drawings before the commencement of work for approval of the Engineer-In-Charge. The arrangement of lubrication shall be provided at wheels of the front axle in the front bogie of both sides of the DT car in a train set. The WFL system shall be a standalone system, compatible with existing controls in the train set.

The Wheel flange lubrication system of a proven design in EMU/metro application shall be provided only at the both wheel of front axle of front bogie in both side DT car. A suitable mechanism shall be provided to ensure that lubricators operate only in the leading position on the train actuate suitably during traversing of the curves automatically.

  • The design of the WFL system shall ensure precise & cyclic application of lubricant on the flange of the wheel(s) so that the lubrication application is uniformly distributed on the flange surface without any excess deposition on the contact surface for avoiding any condition of slip slide.
  • Special care shall be taken by the Contractor for setting of nozzle alignment, so that no flow of lubricant shall be on the tread and braking surface under any circumstance.
  • The system shall be designed to minimise oil/grease and air consumption. Single tube system shall be preferred.
  • The nozzles shall be designed to protect against choking/clogging due to dust. There shall be no movable part in the nozzle.
  • The design shall permit optimised control of oil/grease spray in straight and curved track by suitably modulating the spraying cycles and quantity of oil/grease in the spray.

The spray cycle as above shall be programmable and shall be fine-tuned during field trials and performance of wheels during the Defect Liability period. The programming and mechanical tools of 2 Sets shall be supplied to the Employer after the end of Defect Liability period. Interlocking in built logic shall be made for inhibiting the spraying of WFL when the train set is in stand-still position.

The spray of lubricant shall be time controlled as well as distance controlled. The actuation and spray cycle and quantity shall be decided by the location and degree of the curve which shall be communicated to the system by a centrifugal force sensor, coordinates and parameters of curves informed by the vehicle or/and through other equipment like Gyroscope etc. capable of detecting curves up to 2 degree.

The contractor shall make arrangements to have indication of WFL functionality on the driver console or as per the instruction of the Engineer-in-charge. Arrangement shall be made for the Train Operator to isolate the equipment in case of any defect/malfunctioning. The design of the WFL system shall be Fail Safe.

  • Tenderer shall consider the Schedule of Dimension (SOD) of DMRC (Standard gauge) during designing of the WFL system so that no part of the system shall infringe with the SOD applicable for Line-6.
  • Contractor shall submit calculation on the pressure loss during 1 cycle of operation (in tangent track and in curves of mainline) of WFL system from the pneumatic reservoir.

Contractor shall design the system in such a way that during replacement of the bogie, the system could be easily dismantled and can be easily installed in the new bogie. Contractor shall design the WFL system installed on the coach under frame, minimum intrusion to bogie/car body. Lubricant reservoir and pump shall have necessary provisions to ensure that it can be easily filled, maintained and cleaned. It shall be provided with a lubricant level indicator/dipstick for monitoring of the level of grease/oil.

The WFL reservoir tank shall be secured with suitable and robust clamps to sustain shocks and vibrations encountered during the run of the train set. The interconnecting pipe shall be made of seamless steel tube with rust proof coating or of Stainless steel. Flexible hoses towards the nozzles shall be wire braided and suitable for sustaining the operating air pressure and carrying lubricant air mixture.

The contractor shall provide appropriate shape and size of reservoir tank, pump and controller unit etc. to suit the existing arrangement in the train set. The location of all the components of the WFL system shall be such that it shall not make hindrance of regular inspection, maintenance and replacement of other existing components of the train set.

  • Any electrical/ electronic/ mechanical tapping/ connection taken from the train set should not affect the normal functioning of the train.
  • The system shall comply with international standards of fire. Contractor shall submit required documents for compliance.
  • Electrical Control units shall be installed in the driving cab or any other suitable place agreed by the employer.
  • It is compact and works satisfactorily with 110VDC +/- 30% input voltage.
  • It shall have IP 65 protection against dust and water ingress inside the control unit.

Lubricant- Environment friendly, high viscosity semi-fluid and biologically degradable lubricant shall be used. The lubricant property shall be stable (i.e. Chemical, physical and fluid property) at the wide range of operating temperature in the environment of Delhi. It shall provide the stipulated performance at all operating conditions even when the wheel flange temperature reaches 150°C.

It shall have storage stability of at least one year. The lubricant shall be locally available in India. Tenderer shall provide the name of potential vendors/suppliers from which DMRC can procure the lubricant directly and payment can be done in INR. Contractor shall study the wheel profile of RS system and rail profiles in Line-6 and recommend suitable spray time cycle required for achieving desired performance.

Contractor shall submit a Simulation report on the above in support of the final spray cycle time. There shall be provision in-built in the software of the system to adjust the spray cycle On/Off times and any other operational parameters in the depot by the maintenance staff. The system shall be reliable and maintenance friendly. Time taken to install and dismantle the system from a train set should be minimum.

The failures of the system should be logged, displayed and downloaded by maintenance staff during service checks for easy diagnosis of failures. The contractor shall do the nozzle alignment work after Wheel Reprofiling and Bogie replacement work during the Defect liability period. Interface- Contractor shall be responsible for all the interfacing required during execution of the work such as the activities mentioned but not limited to the below list:

  • Interfacing with DMRC personnel for issuance of ID cards of contractor staff.
  • Interfacing with O&M staff for obtaining a work permit to work in the depot.
  • Interfacing with local authorities for obtaining any clearance certificate as needed.
  • Arranging regular meetings for design finalisation, discussion of monthly progress report etc.
  • The technical specification document, test specification document, test reports etc. shall be submitted to DMRC.
  • The As-Built Drawing (ABD) (4 Copies) in editable pdf as well as in AutoCad Format shall be submitted to DMRC.

Warranty/Defect Liability Period (DLP):

  • The wheel Flange Lubrication system shall be covered for a warranty for a period of 2 years from the date of commissioning of the system in the last train set against manufacturing defect, workmanship problem and satisfactory performance.
  • Any defect/deficiency noticed during this warranty period shall be attended/rectified/replaced by contractor free of cost. If any transportation is required to attend warranty failure, the same shall be borne by the contractor.
  • The failure shall be attended by the Tenderer within 48 hours of occurrence of the failure, failing which, a penalty shall be imposed on the contractor as mentioned below at Clause 10.
  • If any failure is repetitive in nature and it requires design change, then it shall be done after prior approval of the employer. In such a case, the DLP shall be extended by 24 months from the date of completion of the design modification in the complete fleet. Engineer’s decision shall be final.
  • Contractor shall prepare a checklist for scheduled maintenance as per OEM recommendation and implement the same during the DLP with prior approval of the employer.


The implementation of the wheel flange lubrication system underscores DMRC’s commitment to innovation and safety in public transportation. By leveraging advanced technology and stringent quality standards, DMRC continues to set benchmarks for metro rail systems worldwide, ensuring a smooth and reliable commuting experience for millions of passengers daily.

Source: DMRC- Tender Update | Image Credit (representational): DMRC