Customer Challenge

To work on customer train model Contractual Design Requirement List (CDRL) 150/151 approval process. Part of this was to assist in the periodical release of a mass properties report package. This had to consider all elements of both 5-car units and 10-car units.


  • To work in strict accordance with Contractual Design Requirement List (CDRL) 150/151 approval process and ensure the periodical release of VMASS reports.
  • To oversee and document the weighing of individual system test shells, as well as fully equipped cars.


  • Our team reviewed the CDRL 150 (Monthly Mass Report) and CDRL 151 (Final Mass Report) produced by suppliers of various sub-systems and approved or rejected them based on contractual mass requirements.
  • This process involves the comparison of estimated/calculated/actual mass of a given sub-system with the contractual mass.
  • We explored and discussed with the client the possible impact on overall weight of the Unit (5-Car Unit and 10-Car Unit) if the mass is above the contractual mass.
  • Key to this, we proposed a design change to the sub-system, to bring vehicles back to the contractual mass.


  • Updated VMASS report with approved mass of various sub-systems
  • Comprehensive oversight of Test Shell weighing, and completed cars, in the engineering development laboratory in Derby
  • Fully documented real-world weighing


  • Mass Properties Report files were released in the PDM after getting approved by the chief engineer.
  • Weighing Sheets also made available for individual cars.