5.3 Maintenance and inspection

Question 1

Under the Provision and Use of Work Equipment Regulations 1998 (PUWER) the employer has an absolute duty to

Answer 1

maintain work equipment in an efficient state, in efficient working order and in good repair. Here ‘efficient’ relates to how the condition of the equipment might affect health and safety and not productivity.

Question 2

These issues were considered to merit particular attention because of the severity of the harm that could be involved, and because they are commonly encountered during plant and building maintenance. 4

Answer 2

 disturbing asbestos  falls from height  falls of heavy items  inadequate isolations and permits to work.

Question 3

Maintenance programmes may be based on various maintenance methodologies. For the purpose of the NEBOSH Diploma the methodologies may be classified and characterised as: 3

Answer 3

 Breakdown.  Planned preventative.  Condition based.

Question 4

Designing an effective PPM programme for safety-critical machinery requires consideration of the following factors:

Answer 4

 The age and current condition of the machinery.  The nature of its usage – light or heavy duty.  Its breakdown history.  The operating environment (hazardous conditions – hot, dusty, corrosive).  Manufacturer’s recommendations for servicing.  Insurer’s requirements.  Statutory requirements under PUWER, LOLER, EAWR, etc.  The risks to health and safety of malfunction.  The timing of the intervention - the reliability of the schedule for servicing and replacement (the need for condition monitoring).  The effect failure would have on other components and on the process in general.  The availability of spare parts (procurement and storage considerations).  The need to minimise disruption to production (weekends or scheduled shut-downs).  An effective management system for flagging up the need for maintenance and logging maintenance activities.  The competence of the maintenance team / the need to contract in specialist support..

Question 5

Condition monitoring can be an effective tool for diagnosing the symptoms of impending equipment and machinery failures. It may include

Answer 5

sampling and analysis, vibration monitoring, operating parameter measurement, non-destructive testing techniques (NDT) and electrical testing procedures.

Question 6

Outline factors to be considered when developing a planned preventive maintenance programme for safety-critical machinery. 10 marks

Answer 6

Factors to be considered include:  the manufacturer’s recommendations and servicing and insurer’s requirements  the reliability of critical components using diagnostic techniques to predict failure, the effect failure would have on other components and on the process in general, and the need to plan their replacement before failure occurs which would require the storage of spare components  the risks to health and safety of malfunction  the age and current condition of the machinery and its usage, breakdown history and operating environment, whether in dusty areas, in high temperatures or in corrosive atmospheres. Additional factors to be considered would include:  the timing of the maintenance for example at weekends to prevent disruption to production  the methods to be used to identify maintenance periods such as the use of coloured tags and for recording the maintenance once completed  the competence of existing maintenance staff with the possibility that additional specialist training might be required. Reference to the requirements of relevant legislation, such as those contained in HASAWA, the Electricity at Work Regulations and PUWER, would also have gained marks here.

Question 7

Examples of inspections include: 3

Answer 7

 Quick checks before use, such as electric cable condition on hand-held power tools, functional testing of brakes, and lights on mobile machinery.  Weekly checks, such as presence of guarding, function of safety devices, tyre pressures, and the condition of windows, mirrors and CCTV on mobile plant.  More extensive examinations, undertaken every few months or longer, such as general condition of a ladder, close examination of a safety harness and portable appliance testing.

Question 8

The person who actually carries out the inspection should have sufficient knowledge of the equipment to: 3

Answer 8

 Enable them to know what to look at (know the key components).  Know what to look for (fault-finding).  Know what to do (reporting faults, making a record, who to report to).

Question 9

Functional testing of safety related parts Safety related parts might include: 3

Answer 9

 Guards and protective devices such as interlocked guards or light curtains (electro-sensitive protective equipment (ESPE) using active opto-electronic protection devices (AOPD)) which have to operate effectively to keep workers away from danger.  Brakes and lights on mobile work equipment such as forklift trucks.  Emergency stop controls on machinery.

Question 10

Records of equipment inspections do not have to be kept in a particular form, but should normally include: 9

Answer 10

(a) information on the type and model of equipment (b) any identification mark or number that it has (c) its normal location (d) the date that the inspection was carried out (e) who carried out the inspection (f) any faults (g) any action taken (h) to whom the faults have been reported (i) the date when repairs or other necessary action were carried out.

Question 11

If equipment has to run during a maintenance operation and this presents risks, appropriate controls should be introduced to reduce the risk, for example: 3

Answer 11

 provision of temporary guards  limited movement controls  crawl speed operated by hold-to-run controls.