Health + Safety Flashcards
Define what you understand by “hazard” and “risk”.
Hazard - Something with the potential to cause harm/damage to someone/something
Risk - The probability that the hazard will occur multiplied by the consequence if it does happen
Detail the causes of high noise levels in tunnels and describe what consequences may result of excessive exposure. Describe what mitigation measures may be taken and what specific regulations apply.
High noise levels may be caused by:
- pneumatic tools
- loud machinery
- drilling
Consequences will include hearing impairment, loss of quality of life and incapacity for work.
Mitigation measures include: monitoring noise levels at source, wearing ear protectors, good maintenance of machinery. Ensure compliance with Control of Noise at Work Regulations 2005.
Detail the causes of high vibration levels and describe what consequences may result of excessive exposure. Describe what mitigation measures may be taken and what specific regulations apply.
High vibration levels may be caused by:
- pneumatic hand held tools
- ride-on machinery such as trains and TBM’s
Hand held tools will lead to HAVS, loss of feeling in tips of fingers, white fingers, pain in fingers, incapacity for work. Vibrating ride-on machinery could lead to WBV which causes back pains and incapacity for work.
Mitigation measures include: Eliminating vibration at source, rotate work between people, good maintenance, vehicle suspension, good vehicle seats. Ensure to comply with Control of Vibration at Work Regulations 2005.
Detail the causes of high heat levels in tunnels and describe what consequences may result of excessive exposure. Describe what mitigation measures may be taken to reduce the risk.
High heat levels may be caused by:
- hand excavation
- chemical suits
- manual work in compressed air
- using face masks
Consequences will include sweating, dehydration, unconsciousness and potentially death, general fatigue.
Heat risk mitigation will include good job rotation, provision of plenty of water and fluids, good ventilation, designated rest areas to cool down.
Detail the causes of high dust levels in tunnels and describe what consequences may result of excessive exposure. Describe what mitigation measures may be taken to reduce the risk.
High dust levels in tunnels may be caused by:
- drilling of rock
- Drill and Blast
- dirt lifted from the invert of tunnel
- movement of vehicles
- SCL
Consequences of excessive dust exposure will include silicosis and Chronic Obstructive Pulmonary Disease (COPD) leading to lung damage, loss of quality of life and incapacity for work.
Mitigation measures should include good ventilation system, extraction ventilation will contain and remove dust, reduction of dust at source, water sprays/wet drilling, using PPE dust masks.
Detail the causes of vehicle/machinery collisions in tunnels and describe what consequences may result of this. Describe what mitigation measures may be taken to reduce the risk.
Causes of vehicle collisions:
- Poor visibility
- Poor tunnel layout management
- Not separating personnel and vehicle movements
- Poor driver training
Consequences could include death/injury, damage to machinery, delays in programme, damage caused to tunnel.
Mitigation measures should include ensuring good visibility in tunnel, separation of personnel and machinery movements, driver and personnel training.
List three sources of guidance on Health and Safety in Tunnelling.
a) BS 6164:2011 - “Code of Practice for Health and Safety in Tunnelling in the Construction Industry”
b) BS EN 16191 - European standard for Safety of Shield Machines for Soft Ground Tunnelling
c) BS EN 12110 - European standard for Airlocks
Identify the scope and area of application of the Health and Safety at Work Act 1974 and identify the most important requirements of the legislation to you.
It is a general framework for health and safety in the workplace and is a framework for general requirements.
Section 2, duties of the employer to the employee, would be important to me as an employee.
Section 7, general duties of employees, is important to me as it includes others affected by my work,
Identify the scope and area of application of the Management of Health and Safety at Work regulations and identify the most important requirements of the legislation to you.
This is an extension of the Health and Safety at Work Act requirements.
Sections of particular importance to myself:
Reg 3, risk assessment, requires employer to undertake an assessment of risk to employees at the work place.
Reg 4 - Employer shall implement preventative and protective measures in accordance with the principles of prevention.
Describe forced and extraction ventilation systems and highlight the essential requirements of a good ventilation system.
Forced Ventilation - Air is delivered to the tunnel face from fans at the surface or tunnel portal via a duct. Effective air jet distance is approximately 30 times the duct diameter.
Extraction ventilation - Air is removed from the workings by a duct. Fans can be in the tunnel but requires semi or rigid ducting. Effective intake range is approximately 3 times the duct diameter.
Essential requirements of a good ventilation system:
Well positioned ducts
Well maintained ducts
Good source of clean fresh air
Any fans well clear of the tunnel portal
A duct cassette to allow the duct to advance with the tunnel face
Good joints in ducting to prevent loss of air flow
Good use of bends to direct air flow, no kinks which will restrict air flow
Describe the consequences of working in compressed air and the mitigation measures used to reduce the risk.
Consequences could can include acute or chronic decompression illness as health hazards. Safety hazards include loss of containment and potentially fire.
Mitigation should include compliance with “Guide to work in compressed air regulations 1996”, properly designed airlocks and ensuring proper decompression is undergone.
Summarise the health and safety risks associated with grouting and describe what mitigation measures could be used to mitigate these risks.
Leakage of pressurised fluids is a safety risk which could lead to impact or injection injury.
Ensure to use gloves and good PPE as well as good hygiene as mitigation measures.
What sources of methane may be present in tunnelling and what consequences would this lead to?
Sources: Coal measures, domestic gas mains, decomposing organic waste
Consequences: Dependent on exposure limit this could lead to explosion protected equipment, shut down of equipment withdrawing personnel, shut down of power
What sources of Carbon Dioxide may be present in tunnelling and what consequences would this lead to?
Sources: Acid groundwater on limestone or chalk, exhaust and blast fumes
Consequences: De-oxygenation of air and displacement of O2 by CO2
