Are You Up To Date With Your Train Wash Audits?

To achieve suitably cleaned train carriages, wash plants themselves must be maintained to a suitable standard.  Auditing of the wash plant can assess the efficiency, health and safety and operation of the train wash plant to understand how well maintained the train wash equipment is with overall scoring from one to five; one being excellent condition and five being poor condition with major defects or damage.

Where poor outcomes are detected, recommendations can be given to improve the functionality of the wash plant. Nicola Atkinson, rail account manager, delves into some of the detail about train wash audits, and some considerations to ensure efficiency and effectiveness.

Cleaning efficiencies

Part of the audit includes calculating the cleaning efficiency. Taking into account the age and specification of the machine, as well as historical data for the average cleaning efficiency, cleaning efficiency is represented as a percentage.

The test method, SOAP, is specifically designed to give a percentage of the physical cleaning performance of the washer, used only by SOCOTEC.

SOAP testing system (SOCOTEC on-board assessment panel)

Attaching a soiled test panel to a vehicle prior to entering a wash plant enables SOCOTEC to assess the cleaning efficiency, based on how much soil has been removed.

Along with the SOAP test, a number of other factors would be observed and assessed on site as part of the wash plant audit, including:

• The bodyside interference on the brush/flail material
• The rotational speed and direction of the rotors
• Operating strength of the cleaning chemical
• Observation of all other contributory cleaning parameters
• Legionella risk from wash plant system
• Health and Safety assessment of wash plant system
• Condition of Wash Plant structure
• Trade effluent discharge compliance

Operational effectiveness

Operational assessment looks at lineside equipment, structure and aprons, gullies, drains and sumps, pumps, nozzles and pipework as well as the plant.

Typically, the audit will consider the bodyside interference on the brush/flail material to include:

• Brush condition - signs of heavy wear, missing brushes, rotation direction and speed of rotation
• Any non-operational brushes should be investigated and repaired
• Contra-rotating brushes is more effective in cleaning, as it allows for wiping in two directions to remove dirt
• Overlap of the brushes or flails (each type having its own optimum overlap)
• Could the wash cause any damage to the paint and bodywork of the rolling stock?

Nozzles and Pipework

Nozzles in poor condition can decrease the amount of chemicals and water used, thus reducing the lubrication of the brushes and bodyside, therefore the audit looks at:

• Ensuring nozzles are not blocked and thoroughly cleaned
• Any lack of flow for detergents should be investigated
• Checking there are no leakages from the nozzles and pipework
• Tanks should be thoroughly cleaned, without vegetation

Health and Safety assessment of wash plant system

Health and Safety assessment includes details on the concentration of the detergent used and facilities present at the wash plant.

To be compliant, the below must be in place:

• Safely stored chemicals that are correctly labelled
• Hazard signs for chemicals, where appropriate
• Completed COSHH assessments and safety data sheets, where needed
• Access to a fully stocked first aid kit – complete with tamper evident seal
• Access to a fully functioning emergency shower, eye wash facility and fire extinguisher

Trade effluent discharge compliance

Audits on wash plants can ensure smooth running and efficient equipment, but can also help rail depots to comply with their consent to discharge.

The effluent parameter limits are based upon water authority consent to discharge limits, if found to be above these limits the result will be highlighted in red.  Detergent target mix strengths are set by the chemical manufacturers and have a lower, upper and optimum figure.

Excessive chemical dosing may lead to a detrimental effect on trade effluent quality which raises the risk of discharge consent failure. It also reduces stock levels at a much quicker rate, leading to higher running costs. By ensuring the right dosing concentrations are achieved, the client is assured that the operating performance of the wash system is at the optimum level, they are working on the most cost effective setting by minimising waste and the environmental impact is reduced.

Properly implemented, a regular cleaning regime can support a rail depot in reducing costs through minimised water consumption and optimising chemical use to mitigate waste.

Sampling and analysis

Sampling water from the final rinse water, recycled water and emergency showers can determine the presence of bacteria or Legionella – crucial to ensuring the safety and wellbeing of plant operators on site, in line with the Health and Safety Executive’s (HSE) Approved Code of Practice (ACoP) L8.

As part of Legionella control and under HSE ACoP L8, the wash plant requires checking as per the legionella risk assessment and these should be recorded in the legionella control log book. 

These include weekly checks if the train wash utilised recycled water (pH, Biocide checks, conductivity and bacteriological testing) and quarterly bacteriological testing including legionella specific bacteria.