Engineering Change to Improve the Efficiency of OTMR Maintenance

Image © HaslerRail

By Jamie Adamson, Engineering Graduate, First ScotRail

Introduction to OTMR usage on railway vehiclesTechnology• OTMR = On Train Monitoring Recorder (also known as on train data

recorder, incident recorder)• Railway equivalent of “black box”• Monitoring of brake/throttle control circuits, brake pressures,

AWS/TPWS, door controls, driver safety systems, and many more.

Legislation• GM/RT2472 (Data Recorders on Trains – Design Requirements)

– 1990s: Mandatory requirement of all new-build rolling stock– 2000: Mandatory requirement of all existing rolling stock (with 5-year grace

period)

Scope of Task

• Devise new time-saving method to verify that all OTMR system ‘channels’ are recording correctly

• Trial new methods, assess suitability• Revise Vehicle Maintenance Instruction (VMI) tasks, complete risk

assessment• Submit for Vehicle Acceptance Body assurance and Leasing

companies for approval

Present Verification Method

• Activate every switch, lever and button that operates an OTMR channel

• View in real-time with a laptop or take a download and analyse data• Extensively test AWS/TPWS receiver• Test speedometer and WSP• …And do it all again for the other cab!

(Note: ScotRail multiple unit fleet has 584 cabs)

Methods ConsideredMethod 1: Data Download only • Take OTMR data download covering last 3

days of service and check that all channels have been used.

• PROs: works fine for digital channels, takes a short time to verify channel usage

• CONs: No way of ensuring analogue channels work within tolerance

Methods Considered (cont)Method 2: Microsoft Excel Macro • Take OTMR data download covering last 3 days of

service, export to spreadsheet and use a macro to instantly search for channel usage. Full static test of analogue channel systems.

• PROs: Very effective, instant result. Properly verifies analogue channels

• CONs: Pre-requisite knowledge of MS Excel needed. Macro at risk of corruption. Would need re-written if channels were added/removed/renamed.

Methods Considered (cont)Method 3: Download check and real-time rare/analogue channel use• Take OTMR data download covering last 3

days of service, static test of analogue channel systems plus rarely-used isolation channels.

• PROs: Properly scrutinises analogue channels, most likely to gain VAB approval and reduce timescale.

• CONs: Whole process is more extensive, VMI task looks more complex on paper than it is.

Risk Assessment and Evaluation• Methodology follows EC directive, Notified National Technical Rules

(NNTR’s) and RGS (Railway Group standards)

Common Safety MethodEC Regulation 352/2009

Notified National Technical Rules (NNTRs)Controlled by DfT

GM/RT2472ERA/TD/2011-01/XANational Rule Annex Section 9.6 (Recording Device)

• GM/RT2472 has vague guidance regarding OTMR maintenance standards

• Common Safety Method was used for full risk assessment of engineering change

Risk Assessment and Evaluation – CSM CriteriaCriterion Example Assessment

Additionality Series of small changes that collectively evolve into a significant change

No minor changes to any First ScotRail OTMR systems that would develop this engineering change into a significant change.

Failure Consequence OTMR total failure in traffic; not detected until next download opportunity

OTMR discovered as faulty, and will be repaired at depot. Unit can continue in traffic provided the other driving cab’s OTMR is functioning healthily, but schedule for repair ASAP as a matter of course.

Novelty Task format exists in similar form on class 334 VMI.

Task has not been amended significantly from new, so no examples of task change to form a precedent.

Complexity Maintenance procedure change only. No physical change to on-train systems

Revision of task relies more on OTMR data analysis. Staff awareness of expected channel behaviour should be checked.

Analogue channels cannot be precisely checked using stored OTMR data.

Real-time checking of analogue channels will continue, to ensure that calibration of these channels matches precisely with the systems they are monitoring.

Monitoring Process can be monitored to ensure new procedure is being followed correctly.

Hard copy of channel check tick-sheets and back-up of OTMR data is archived. ‘Product checks’ and competence refresher can reduce likelihood of oversight.

Reversibility Ability of the change to be ‘un-done’ If necessary, technical concession to revert to previous procedure could be given until solution to change is provided.

Outcome

• VMIs undergoing independent assurance at present• My understanding of OTMRs and onboard vehicle systems has

greatly improved• Selling the benefits of the change to depots was a challenge• Delving into EC and ERA (European Rail Agency) interoperability

legislation

Future Developments

• Remote Condition Monitoring– Seeing real-time data accumulated by the OTMR from the comfort of

the office..

– Boolean logic helps identify potential defects and notify by email, while the train is still in traffic

– Can verify most OTMR channels are working in an instant.

– Expand range of monitored systems to include door opening/closing times, compressor running time

• Already working on East Coast class 91 fleet• Trial on class 158s with First ScotRail

Thank you for listening.