Personal safety
2Personal Safety
General precautions
► Read carefully the personal safety instructions which are available in TNS 01 Annex 7.
► The surveyor must be suitably dressed for the space to be inspected
► This includes shoes, gloves & hard hat. The shoes should not give rise to a spark.
► The surveyor should carry a suitable torch, depending on the space to be inspected, an explosion-proof torch may be required
3Personal Safety
General precautions
► Watch for : Badly fixed, unsteady or unguarded scaffolding
Timber of scaffolding in poor condition or overhanging
Wooden hatch covers badly secured or missing
Ladder rungs missing or in poor condition
Decks, platforms etc., slippery or icy.
4Personal Safety
General precautions
► Watch for :
Deck openings open or unguarded
Surveying below men working overhead or beneath loads being handled
Surveys of tanks or compartments during ballasting or heavy lifting of cargoes
Electric welding without proper eye protection
5Personal Safety
► Do not conduct surveys alone or when workers have departed
► Internal inspections, particular care when
Inadequate lighting
Slippery surfaces
Open manholes in stringer plates
Corroded handrails & ladders
Doubt about ventilation and atmosphere
General precautions
6Personal Safety
General precautions
► Engulfment Hazards
Loose, granular material stored in holds or tanks, such as grain, sand, coal, or similar material can engulf and suffocate a worker.
The loose material can crust or bridge over and break under the weight of a worker
7Personal Safety
General precautions
► The surveyor must observe the safety requirements of third parties (shipyard, terminal, owners, authority, etc.)
► Slightest dizziness or lack of balance is a warning & the surveyor should leave the compartment immediately
Optimum oxygen level to be 20.8 to 21%
Combustible gases less than 10% of the lower explosive limit.
Toxins within acceptable limits
Maximum hydrogen sulphide level 10ppm
Maximum benzene level 10 ppm
8Personal Safety
11
14
16
19.5
20.8
22
0 5 10 15 20 25
Difficult breathing, death inminutes
Faulty Judgement, Rapid Fatigue
Impaired judgement & breathing
Oxygen Deficient Atmoshere
Normal
O2 Enriched
% OXYGEN
General precautions
9Personal Safety
General precautions
► Flammable atmospheres
Two things make an atmosphere flammable: the oxygen in the air and a flammable gas, vapor or dust in the proper mixture
Different gases have different flammable ranges. If a source of ignition is introduced into a space containing a flammable atmosphere, an explosion will result
An oxygen enriched atmosphere (above 22%) will cause flammable materials, such as clothing or hair, to burn violently when ignited.
10Personal Safety
General precautions
► Spaces poor in oxygen include :
Spaces that contain less than 20.8%
Heavily corroded spaces : the corrosion process consumes O2
Enclosed spaces partially filled with sea or fresh water experience a reduction in O2 & the possible generation of toxic gases.
Void spaces, M/E crankcases, edible oil tanks, etc.
11Personal Safety
Confined spaces
12Personal Safety
Confined spaces
► Prior to enter a confined space, check :
When opened & how long ventilated
Ventilation arrangements and means of verifying atmosphere during the survey
Whether surrounding compartments are full &, if so, with what
Nature of last cargo, if applicable
Condition of the compartment (ballast tk. Rust)
On average, there are 200 deaths per year in the Marine Industry as a result of confined space entries
On average, there are 200 deaths per year in the Marine Industry as a result of confined space entries
13Personal Safety
Confined spaces
► Ventilation arrangement
14Personal Safety
Never trust your senses to determine if the air in a confined space is safe !!!
You can not see or smell many toxic gases and vapors, nor can you determine the level of oxygen present.
Confined spaces
15Personal Safety
Confined spaces
► Over 50% of workers who die in confined spaces are attempting to rescue other workers
Rescuers must be trained in and follow established emergency procedures and use appropriate equipment and techniques (lifelines, respiratory protection, standby persons, etc)
Steps for safe rescue should be included in all confined space entry procedures.
Unplanned rescue, such as when someone instinctively rushes in to help a downed co-worker, can easily result in a double fatality, or even multiple fatalities if there are more than one "rescuer"
Remember, an unplanned rescue will probably be your lastRemember, an unplanned rescue will probably be your last
16Personal Safety
Confined spaces
► Prior to enter a confined space, check :
Safety & communication arrangements
• External to the compartment being surveyed
• Internal, during the survey
Review the entry certificate / permit
• When was it issued and its validity (incl. times)
• By whom & when next verification will be made
Tankers - ISGOTT regulations to be observed
• International safety guide for oil tankers & terminals
17Personal Safety
Confined spaces
► Check the isolation of the compartment :
IG lines blanked, valves closed & marked
P/V lines blanked, valves closed & marked
Cargo / ballast lines, at least 2 valves closed & marked
Drainage / flushing of cargo pipe lines passing through the tank
Adjacent compartments not filled with toxic material
Heating coils shut off
18Personal Safety
Confined spaces
► Dangerous spaces
Note - associated areas are considered as dangerous spaces
Gas free certificate - safe for access
Date / time of last verification - usually checked every 3 hours, assuming normal ventilation
The certificate should be valid for the duration of the survey
19Personal Safety
Confined spaces
► Toxic spaces
Spaces designed to contain toxic material
Loading areas also included as dangerous spaces
The space must not be entered if breathing apparatus is required
Special equipment for testing for toxic substances - Draeger tubes
Testing for oxygen
20Personal Safety
Confined spaces
► Boilers
Enter when both manholes have been opened
After ventilation & cooling
If other boilers are in service check that boiler is properly isolated on steam, water and smoke sides
• At least two valves between the boiler under survey and the boiler under steam
21Personal Safety
Check-list for entering confined spaces
► A check-list is available in TNS 01 Annex 7. Do not enter a confined space until you have considered every item of the check-list, as well as any other item of concern, and have determined the space to be safe
► The check-list covers the following topics : Confirmation that you will be accompanied during entry
Verification of testing equipment and qualification of testers
Testing of the atmosphere for oxygen level, toxic or flammable gases
Continuous monitoring of the atmosphere during survey
Ventilation of the confined space
Isolation of the confined space
Use of adequate clothing and safety equipment
Standby and rescue procedures
Entry permit
Remember, the final decision is yours. If you are not confident that the space is safe for entry, do not enter it.
Remember, the final decision is yours. If you are not confident that the space is safe for entry, do not enter it.
22Personal Safety
Rafting
► Boats or rafts may be used for the close up survey of ballast or cargo tanks under the following conditions:
Heavy duty inflatable boats having residual buoyancy and stability
The surface of the water in the tank to be calm
The expected rise of water within the tank should not exceed 0.25 m
Water level to be stationary or falling
23Personal Safety
Rafting
► The tank must contain clean ballast with NO sheen
► All conditions for the entry of confined spaces should be observed
► At no time should the water level be allowed to be within 1 m from the deepest under deck web
► Common venting & IG systems to be blanked
► Safety meeting to be conducted prior to entry
► Additional requirements
Lines of communication to be established
Adequate safety lighting
Raft tethered to the ladder
Person on the ladder sighting the raft at all times
All raft personnel with lifejackets
Rescue equipment immediately available