The concern related to passenger carriages which had been reconfigured for a trial period, but the reconfiguration had not been done in accordance with the risk assessment which had been submitted to the regulator.
The reporter expressed a safety concern regarding the current trial where two reconfigured carriages have been modified to take additional passengers.
The reporter stated that the carriages have not been modified as shown in the safety risk assessment. The hanging hand-holds included in the configuration drawing have not been fitted on the test train and it appears that a significant proportion of the standing passengers will not have access to anything to hold on to except for a small number of support poles. This could potentially affect the centre of gravity of a crush-loaded train and is likely to result in passenger fall injuries. The reporter understands that this issue is currently attracting adverse comment from members of the public.
The reporter stated that clearly the scope of the change as implemented is significantly different from the change assessed by the safety risk assessment and that the safety risk assessment does not reflect the actual project scope.
The reporter is concerned that an invalid rationale was used to answer one of the safety risk assessment questions and that the answer should have been based on the nature of the change rather than the extent of the change.
I refer to the REPCON report provided to us concerning the trial being conducted whereby two carriages have been reconfigured.
The report raised a number of issues, namely:
The carriages have not been modified as shown in the safety risk assessment.
The hanging hand-holds included in the configuration drawing have not been fitted on the test train. The drawings in the safety risk assessment were conceptual only and were clearly marked as such. Grab handles and grab poles were included in the risk assessment and it was identified that there was a safety risk associated with the holds in that people would not have access to them if insufficient grab handles or poles were installed and that if the grab handles were only installed on the roof, a short person may not be able to reach them.
The absence of hanging handholds appears to mean that a significant proportion of the standing passengers will only have support poles to hold onto and this could affect the gravity of a crush loaded train.
Advice has been sought from the relevant rolling stock engineers and they have advised that "Car lateral balance is unaffected in crush load". A true crush load would have an even distribution of passengers throughout a carriage - that is, there would be the same number of people sitting/standing. Roll centres would remain essentially the same and the net increase roll moment above the existing asymmetry is insignificant.
The scope of change as implemented is significantly different from the change assessed by the safety risk assessment
We disagree with this statement and refer to the answer to issue 1 above.
The safety risk assessment was specifically written for the trial and states that the cars will be returned to their original configuration after the trial. The safety risk assessment also explicitly states that if there is a future decision to reconfigure carriages then the safety risk assessment will be revised.
An invalid rationale was used to answer the safety risk assessment question.
The rationale used to answer the question (no substantial modification of rolling stock) of the safety risk assessment was correct, given the nature of the change and that the modification was only for trial purposes on 2 cars out of the whole fleet.
Following an assessment by the ONRSR 'rolling stock' technical specialist, the ONRSR is satisfied with the response provided by the operator. The ONRSR will continue to seek an update from the operator regarding the trial outcomes of the carriages, within its regular 'rolling stock' consultation held with them.
Additionally, we will also consider the report and its content for the planning of future compliance activities.