The focus of this guidance is on the prevention of ADT overturn events by adoption of good working practices. However, if a site operator is faced with an ADT overturn it is equally important to give guidance of the safe recovery of a machine post incident.
It is likely that the prevailing mind-set of a site operator who deems that ADT overturns are somehow ‘routine’ is also likely to be that recovery of the machine is also a routine event. In reality this is far from the case as the risk associated with vehicle recovery could in many cases be greater that the risk associated with the overturn itself.
At many sites the approach in the past has been to right an overturned vehicle as quickly as possible using whatever equipment was available, usually with a hydraulic excavator and thus allow normal operations to proceed without delay. This is a poor and unacceptable practice for the following reasons:
- Persons may be put at unnecessary risk during the recovery operations if these are not adequately planned and supervised
- Further vehicle damage (and cost) may be incurred in the recovery operation if not properly planned
- An important chance to learn from the incident may be lost if the vehicle is recovered quickly – and with it a lost opportunity to prevent a future incident
- The machine may be put back into service without adequate safety checks
- The incident may be reportable to the HSE either as an injury incident or dangerous occurrence (if the incident was called by a fall of ground) and this may mean the scene needs to be left undisturbed until directed otherwise.
Safe steps in the recovery of an overturned vehicle
It is not possible to give comprehensive guidance on the recovery of an overturned ADT. Although common modes of failure can be identified each event is unique and should be treated as such. However, the following steps should be considered before any attempt is made to right the vehicle:
- Make the area around the vehicle safe - this will almost certainly mean suspending all other mobile plant activity in the area around the vehicle. In the event of cab overturns consideration should be taken to prevent or contain possible leaks of fuel or hydraulic oils.
- In the event of serious injury or dangerous occurrence and likely RIDDOR reporting of the incident consideration should be given to making the area an exclusion zone pending investigation / advice from HSE.
- Even if the ADT driver appears to be unhurt they should be prevented from operating other machines until they have been assessed for the effects of shock etc. Particular care should be taken in the event of cab overturns to ensure the driver has no effect of concussion or other hidden injury.
- It is now common for many UK operators to carry out Drugs and Alcohol testing of employees involved in significant incidents such as an ADT overturns. This is to be recommended as it can be used to rule out this as a possible causal factor.
- A comprehensive statement of events should be taken from the driver and any other witnesses as soon as is practically possible after the event.
- A comprehensive photographic record of the event should be made including the approach areas to the incident site itself.
Planning the recovery operation:
- The recovery operation will always require the completion of a formal and recorded assessment of risk, together with a Safe System of Work (SSOW). The operation should be closely supervised by a suitably competent and experienced person.
- The SSOW should detail exactly how the machine is to be righted, who is to carry this out, and what controls are to be put in place to control the hazards identified in the risk assessment
- Consideration should be given to the experience of the site team in relation to previous similar events. Any risk assessment or SSOW documents from previous events should be reviewed and learnings applied to the current recovery operation. In the event that the site team have not got the required competencies to effect the recovery themselves, guidance should be sought from off site.
- Subject to suitable risk assessment a correctly sized hydraulic excavator maybe appropriate to right the overturn – particularly if this is a body only event.
- In some cases it may be deemed necessary to utilise the services of a specialist heavy plant recovery company.
The recovery operation:
- In the case of a skip overturn it is usually good practice to remove as much of the remaining material from the dumper body as possible – this will minimise the load for the recovery machine(s).
- The parking break should be applied before the machine is righted.
- A rigorous exclusion zone should be enforced around the machine for the duration of the recovery operation.
After righting the vehicle:
- A comprehensive examination of the machine by a suitably competent person should be undertaken prior to any attempt to move it under its own power.
- The machine should be taken to an appropriate workshop or similar safe area to be thoroughly checked over before consideration is given to put it back into service. This is particularly the case in cab and whole machine overturns.
- Brake efficiency, tyre pressure and condition etc should also be noted at this point as these may be factors to consider when determining the cause of the incident. It may also be appropriate to download any vehicle telemetry data if the vehicle has this facility as this can be used to determine speed etc at the time of the incident.
Post incident investigation:
- It is vital that every overturn incident is investigated as a high potential incident and that the root causes of the incident are determined.
- It is often far too easy to attribute root cause as ‘driver error’. This will often overlook other causational factors that were in the direct control of the site management.
Learnings from the investigation should be incorporated in future working at the site and shared with other sites and wider industry bodies as appropriate.
Subject to a comprehensive risk assessment a suitably sized hydraulic excavator may be appropriate for the recovery of an overturned dumper body – however, each incident should be assessed separately before deciding on the recovery method to be used