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Operatives and Specialists – Excavations and Confined Spaces (2023)

Construction Test > Operatives and Specialists – Excavations and Confined Spaces (2023)

You need to answer at least 39 out of 43 questions correctly to pass the Excavations and Confined Spaces Test for Operatives and Specialists. Answers may be reviewed after each question or at the end of the test. Good luck!

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List of questions in above test (quick view). Click question box to reveal correct answer.
1. Excavations are considered dangerous at what depth? Give ONE answer
A 1 metre
B 3 metres
C 50 centimetres
D There is no specified depth for dangerous excavations
Correct Answer: D There is no specified depth for dangerous excavations
Explanation: Excavations of any depth can be considered dangerous.
2. Which of the following are common causes of death or injury when working in excavations? Give ONE answer
A All of the above
B Excavation collapse
C Exposure to dangerous gases
D Hitting live services
Correct Answer: A All of the above
Explanation: These are all potentially fatal incidents.
3. An excavation is safe to work in if there are no obvious hazards. True or false? Give ONE answer
A FALSE
B TRUE
Correct Answer: A FALSE
Explanation: The safety of an excavation can be compromised by many seen and unseen factors.
4. AS LITTLE AS how much soil is enough to prove fatal to a body trapped underneath? Give ONE answer
A 1 cubic metre
B 2 cubic metres
C 3 cubic meters
Correct Answer: A 1 cubic metre
Explanation: 1 cubic metre of soil can weigh 1 tonne - enough to crush a human body.
5. Which of the following will increase the risk of collapse in an excavation? Check ALL that apply
A Excavation supports
B Groundwater in the excavation
C Heavy rain
D The ground drying out
Correct Answer: B Groundwater in the excavation, C Heavy rain, D The ground drying out
Explanation: All these can increase the risk of collapse - apart from supports.
6. What is the BIGGEST risk when excavating near a wall or a structure? Give ONE answer
A That it will decrease visibility in the excavation
B That it will infringe on private property
C That it will weaken the stability of its foundations
D That people may drop items into the excavation
Correct Answer: C That it will weaken the stability of its foundations
Explanation: Excavations may undermine the stability of walls or structures that are nearby.
7. Someone suggests diverting the route of on-site construction vehicles so they pass alongside an excavation. What is the MAIN risk here? Give ONE answer
A That it will distract workers in the excavation
B That noise from the vehicles may drown out communication within the excavation
C That the weight of these vehicles may cause the excavation to collapse
D That workers exiting the excavation may be struck by on-site traffic
Correct Answer: C That the weight of these vehicles may cause the excavation to collapse
Explanation: Heavy vehicles operating too close to an excavation may weaken the walls, increasing the risk of collapse.
8. When should excavation supports be installed? Give ONE answer
A Before anyone enters an excavation
B If there has been heavy rainfall on-site
C If there is thought to be a high risk of collapse
D When the excavation is deeper than 2 metres
Correct Answer: A Before anyone enters an excavation
Explanation: It is good practice to install supports before anyone enters the excavation.
9. What is the purpose of wheel stop blocks? Give ONE answer
A To ensure road traffic does not drive into an unattended excavation
B To lock pulley systems whilst in use at the excavation
C To stabilise vehicles working alongside the excavation
D To stop vehicles coming too close to the excavation
Correct Answer: D To stop vehicles coming too close to the excavation
Explanation: Wheel stop blocks ensure vehicles do not come too close to an excavation.
10. What are TWO ways of ensuring members of the public are not put at risk by an excavation? Give TWO answers
A Ensure the excavation is lit at night or in low light conditions
B Ensure the excavation is manned at all times
C Erect barriers around the excavation
D Install a motion-sensor alarm system around the perimeter
Correct Answer: A Ensure the excavation is lit at night or in low light conditions, C Erect barriers around the excavation
Explanation: Lighting and barriers are both recommended ways to ensure the public are not put at risk by excavations.
11. Which is the safest way getting in and out of an excavation? Give ONE answer
A A leg up from a colleague
B A rope and pulley mechanism
C A stairway dug into the wall
D A tied ladder
Correct Answer: D A tied ladder
Explanation: A tied ladder is a secure way of accessing an excavation.
12. Who must inspect an excavation before work can begin? Give ONE answer
A A competent person
B The health and safety manager
C The site manager
D The workers who will be entering the excavation
Correct Answer: A A competent person
Explanation: Excavations must be inspected by a competent person.
13. How often should excavation inspections take place? Give ONE answer
A After every shift is completed
B Before every shift, including after breaks
C Once each day before work begins
D Only when there has been heavy rainfall
Correct Answer: B Before every shift, including after breaks
Explanation: Inspections must take place before every shift begins
14. You are working in an excavation, and are obliged to take a thirty minute break for heavy rainfall to pass. What now? Give ONE answer
A Begin work again if the excavation seems unaffected
B Do not begin work until a competent person has inspected the excavation
C Do not begin work until you have bailed out water in the trench
D Stop all work for the day
Correct Answer: B Do not begin work until a competent person has inspected the excavation
Explanation: A competent person must inspect an excavation following any event that may have affected its strength.
15. You are inspecting an excavation before shift, and notice a support is coming loose. What should you do? Give ONE answer
A Begin work as normal, since the other supports appear to be in good condition
B Fix the defect, and begin work
C Record the defect, and begin work until a solution can be found
D Record the defect, and fix it immediately
Correct Answer: D Record the defect, and fix it immediately
Explanation: All defects found upon inspection must be recorded and immediately fixed before work can begin.
16. You are inspecting an excavation before shift, and find that it is safe to work in. You may now begin work: true or false? Give ONE answer
A FALSE - you must first record the inspection
B TRUE - you have done everything required to begin work
Correct Answer: A FALSE - you must first record the inspection
Explanation: All inspections must be recorded, even if no defects are found.
17. Some fumes and poisonous gases can be heavier than air. Why is this a risk? Give ONE answer
A Because heavier gases are more flammable
B Because they act like a liquid, so can fill a low space and deprive workers of oxygen
C Because they have no smell, so their poisonous effects can go unnoticed
D It is not a risk
Correct Answer: B Because they act like a liquid, so can fill a low space and deprive workers of oxygen
Explanation: Gases heavier than air will "pour" into a space and displace oxygen.
18. Which of the following gases are NOT heavier than air? Give ONE answer
A Carbon dioxide
B Exhaust fumes
C Helium
D Methane
Correct Answer: C Helium
Explanation: Many naturally occurring gases and fumes created through work can be heavier than air.
19. Which of the following is NOT recommended as part of a safe system of work in excavations? Give ONE answer
A Continuous monitoring of gas levels within the excavation
B Only spending short periods of time in the excavation
C Pumping fresh air into the space
D Using solvent-free products that do not produce fumes
Correct Answer: B Only spending short periods of time in the excavation
Explanation: Gas and fume levels in an excavation should always be mitigated or monitored.
20. Which ONE of the following is the MOST frequent cause of accidents relating to underground services? Give ONE answer
A Faulty equipment
B Reckless digging
C Unexpected cables
D Work that is badly planned
Correct Answer: D Work that is badly planned
Explanation: Contact with underground services is dangerous, and is most frequently caused when work is badly planned.
21. Which of the following are examples of underground services? Check ALL that apply
A Archaeological finds
B Cellars
C Fibre optic cables
D Gas lines
E Sediment layers
F Sewers
Correct Answer: C Fibre optic cables, D Gas lines, F Sewers
Explanation: Underground services include electric or fibre optic cables, sewer or water pipes, and fuel pipes, among other services.
22. What is the BIGGEST risk when a service is struck during work? Give ONE answer
A It may cause fatal injury
B It may create costly delays
C It may cut vital services from the area
D It may result in major lawsuits
Correct Answer: A It may cause fatal injury
Explanation: Striking a service can result in fatal injury, or death.
23. What will happen if an underground service cannot be disconnected prior to work beginning? Give ONE answer
A This will not affect your system of work
B Work will not begin until the service is disconnected
C You will be able to tell it is live when you look at it
D You will be informed, and safety measures will be put in place
Correct Answer: D You will be informed, and safety measures will be put in place
Explanation: Work may continue if a service cannot be disconnected - but safety measures must be put in place.
24. How will you know the location of underground services before excavation work begins? Give ONE answer
A It will be clearly indicated
B You must NEVER work where there are underground services
C You will use specialist detecting equipment
D Your employer will arrange to have plans sent through by the utility owners
Correct Answer: D Your employer will arrange to have plans sent through by the utility owners
Explanation: Your employer is responsible for sourcing information about the location of underground services.
25. What are a CAT and a genny? Give ONE answer
A These are items of PPE for people working near electricity
B These are safety barriers to keep people out of an exclusion zone
C These are tools to help you avoid striking underground cables
D These are two safety roles performed by construction workers
Correct Answer: C These are tools to help you avoid striking underground cables
Explanation: A cable avoidance tool (CAT) and a genny will help detect underground cables.
26. Who can use scanning equipment? Give ONE answer
A All workers who will be carrying out an excavation
B Only a specialist contractor
C Only competent, trained, and authorised people
D Only the person conducting the risk assessment
Correct Answer: C Only competent, trained, and authorised people
Explanation: You must be competent, trained, and authorised to use equipment for survey and scanning.
27. How should you disconnect underground services? Give ONE answer
A Underground services must NEVER be disconnected
B You should inform all local residents and businesses first
C You will contact the utility owners
D Your employer must arrange for this where possible
Correct Answer: D Your employer must arrange for this where possible
Explanation: Your employer will arrange for services to be disconnected, if this is possible
28. Your team has used all the required scanning tools and surveys to identify the approximate location of a cable. What can be done next to locate its exact location? Give ONE answer
A Dig a trial hole by hand
B Do a close-quarters radar survey
C Use a cable avoidance tool on the approximate location
D You cannot get a more accurate location than this
Correct Answer: A Dig a trial hole by hand
Explanation: Digging a trial hole by hand will help you precisely and safely locate the cable before beginning work.
29. When should breathing apparatuses be recommended? Give ONE answer
A If a worker has an existing lung condition
B In deep excavations
C Only as a last resort
D They should never be recommended
Correct Answer: C Only as a last resort
Explanation: Breathing apparatuses may appear in safe systems of work, but should only be used as a last resort.
30. When excavating, you come across a yellow service. What service is this likely to be? Give ONE answer
A Communications
B Electricity
C Gas
D Water
Correct Answer: C Gas
Explanation: Gas services are usually yellow - but this is not always the case.
31. What service is likely to be coloured red or black? Give ONE answer
A Communications
B Electricity
C Gas
D Water
Correct Answer: B Electricity
Explanation: Electricity services are likely to be coloured red or black - but this is not always the case.
32. You are working in a confined space, and a colleague starts to complain of dizziness. What should you do? Give ONE answer
A Check if you can smell gas where they are
B Check that they are sufficiently hydrated
C Encourage them to take deep breaths and rest
D Ensure everyone immediately exits the space
Correct Answer: D Ensure everyone immediately exits the space
Explanation: Dizziness can indicate dangerous levels of fumes or gases. You must ensure everyone is warned and leaves the space immediately.
33. Which of these may present the risks of a confined space? Check ALL that apply
A A basement
B A large unventilated room
C An open field
D An open trench
Correct Answer: A A basement, B A large unventilated room, D An open trench
Explanation: The risks associated with confined spaces can be present even if the space is large, or not entirely enclosed.
34. Breathing difficulties will occur when oxygen levels in the air fall below what level? Give ONE answer
A 10%
B 30%
C 40%
D 60%
Correct Answer: A 10%
Explanation: Normal air is about 21% oxygen. Levels below 10% will cause respiratory difficulties.
35. Welding in a confined space may deplete oxygen levels. True or false? Give ONE answer
A
B TRUE
Correct Answer: B TRUE
Explanation: Hot works burn up oxygen, which may lead to dangerously low levels in a confined space.
36. Which ONE of the following may cause low levels of oxygen in an enclosed tank? Give ONE answer
A Atmospheric pressure
B Convex walls
C Moss and algae
D Rust
Correct Answer: D Rust
Explanation: Rust (oxidisation) can deplete oxygen levels in an enclosed space.
37. What hazard is created by too much oxygen in the air? Give ONE answer
A Breathing becomes more difficult
B Fumes can become more noxious
C Injuries are more easily sustained
D Items become more flammable
Correct Answer: D Items become more flammable
Explanation: Objects will burn more easily, and faster, with higher levels of oxygen.
38. What level of oxygen in the air is enough to create a hazard? Give ONE answer
A 25%
B 35%
C 40%
D 60%
Correct Answer: A 25%
Explanation: A 4% increase in oxygen levels will create a significant hazard.
39. Whilst undertaking a soldering job in a confined space, you take a lunch break. What must you do? Give ONE answer
A Ensure someone is monitoring the unattended torch whilst you are away
B Ensure the torch is not near any flammable items
C Ensure the torch is properly switched off
D Remove and isolate the torch
Correct Answer: D Remove and isolate the torch
Explanation: Leaks from items like hoses and torches may go unnoticed. When not in use, they must be removed from confined spaces and isolated.
40. What are TWO ways dangerous levels of carbon dioxide may be created? Give TWO answers
A Acidic rain falling on chalky ground
B Agitating slurry during excavation
C Large, enclosed bodies of water left stagnant
D Many people working in a confined space
E Use of epoxy resins in an enclosed space
Correct Answer: A Acidic rain falling on chalky ground, D Many people working in a confined space
Explanation: Carbon dioxide is exhaled by humans when breathing, and is also produced by chalky ground - especially if it is exposed to acidic rainfall.
41. You smell rotten eggs whilst working in a sewage tunnel. What does this mean? Give ONE answer
A Nothing in particular
B The sewage is giving off hydrogen sulphide, which is harmless
C The sewage is giving off hydrogen sulphide, which may create breathing difficulties
D There has been a methane leak, and you must leave the tunnel immediately
Correct Answer: C The sewage is giving off hydrogen sulphide, which may create breathing difficulties
Explanation: Hydrogen sulphide smells of rotten eggs, and in large quantities may displace oxygen in the air.
42. What are TWO perspiration-related health problems that can be caused by work in confined spaces? Give ONE answer
A High humidity can cause excessive perspiration, which will quickly lead to fatigue
B High humidity can prevent perspiration evaporating, making it difficult for your body to regulate its temperature
C High temperatures can cause excessive perspiration, which causes you to lose vital salts
D High temperatures cause you to drink more, which causes excessive hydration
Correct Answer: B High humidity can prevent perspiration evaporating, making it difficult for your body to regulate its temperature, C High temperatures can cause excessive perspiration, which causes you to lose vital salts
Explanation: High humidity will stop sweat evaporating properly, so your body cannot regulate its temperature effectively. High temperatures can also lead to excessive sweating, which depletes your body of vital salts.
43. Who is primarily in charge of executing the exit plan when a confined space becomes dangerous? Give ONE answer
A All workers in the space are primarily responsible for the exit plan
B The attendant, who must remain at the entrance to the space
C The health and safety manager
D The on-site manager
Correct Answer: B The attendant, who must remain at the entrance to the space
Explanation: An attendant must always man the entrance to a confined space, and is primarily responsible for setting the exit plan in motion.