PERSONAL FALL ARREST AND FALL RESTRAINT SYSTEMS
It is important for you to understand the difference between a fall arrest system and fall restraint system. These are most commonly used in the construction industry, but may apply to many other situations where employees must work at heights.
FALL RESTRAINT: A fall restraint system consists of the equipment used to keep an employee from reaching a fall point, such as the edge of a roof or the edge of an elevated working surface. The most commonly utilized fall restraint system is a standard guardrail. A tie off system that "restrains" the employee from falling off an elevated working surface is another type of fall restraint.
FALL ARREST: According to the definition in the Federal OSHA standard, a personal fall arrest system means a system used to arrest an employee in a fall from a working level. It consists of an anchor point, connectors, a body belt or body harness and may include a lanyard, deceleration device, lifeline, or suitable combinations of these. The entire system must be capable of withstanding the tremendous impact forces involved in stopping or arresting the fall. The forces increase with the fall distance due to acceleration (a person without protection will free fall 4 feet in 1/2 second and 16 feet in 1 second!).
Let's review 5 key requirements for fall arrest systems:
1) Body belts may not be used after 12/31/97. In the meantime, body belts can only be used if the system limits the maximum arresting force on an employee to 900 pounds. A maximum arresting force of 1800 pounds is allowed when a body harness is utilized. In some jurisdictions, such as Washington State, belts are currently not allowed for fall arrest purposes.
2) The system must be rigged so that an employee cans neither free-fall more than 6 feet nor contact a lower level. After the free-fall distance, the deceleration or shock absorbing component of the system must bring an employee to a complete stop within 3.5 additional feet.
3) The anchorage point must be capable of supporting at least 5000 pounds per employee. Most standard guardrail systems are not adequate anchorage points because they are not built to withstand the impact forces generated by a fall.
4) The system's D-ring attachment point for body harnesses shall be in the center of the employee's back near the shoulder level.
5) The system components must be inspected for damage and deterioration prior to each use. All components subjected to the impact loading forces of a free-fall must be immediately removed from service.
Personal Fall Arrest System
A Personal Fall Arrest System is comprised of three (3) key components – Anchorage connector; Body wear; and Connecting device.
While a lot of focus has been given to anchorage connectors and body wear (full-body harnesses), when discussing fall protection, the connecting device (a shock-absorbing lanyard or self-retracting lifeline) between these two components actually bears the greatest fall forces during a fall.
Anchorage: Commonly referred to as a tie-off point (Ex: I-beam, rebar, scaffolding, lifeline, etc.)
Anchorage Connector: Used to join the connecting device to the anchorage (Ex: cross-arm strap, beam anchor, D-bolt, hook anchor, etc.)
· Anchorages must be capable of supporting 5,000 pounds (22kN) of force per worker.
· Must be high enough for a worker to avoid contact with a lower level should a fall occur.
· The anchorage connector should be positioned to avoid a “swing fall.”
Body Wear: The personal protective equipment worn by the worker (Ex: full-body harness)
· Only form of body wear acceptable for fall arrest is the full-body harness.
· Should be selected based on work to be performed and the work environment.
· Side and front D-rings are for positioning only.
Connecting Device: The critical link which joins the body wear to the anchorage/anchorage connector (Ex: shock-absorbing lanyard, fall limiter, self-retracting lifeline, rope grab, etc.)
· Potential fall distance must be calculated to determine type of connecting device to be used – typically, under 18-1/2 ft. (5.6m), always use a self-retracting lifeline/fall limiter; over 18-1/2 ft. (5.6m), use a shock-absorbing lanyard or self-retracting lifeline/fall limiter.
· Should also be selected based on work to be performed and the work environment.
· Shock-absorbing lanyards can expand up to 3-1/2 ft. (1.1m) when arresting a fall; attach lanyards to the harness back D-ring only; never tie a knot in any web lanyard – it reduces the strength by 50%.
Hierarchy of Fall Protection
It is generally accepted by governing bodies that the hierarchy of fall protection should provide the starting point for considering what type of fall protection system is required.
1. Eliminate the risk
Avoid work at height where possible or locate plant and equipment in safe locations where there is no risk of a fall.
2. Guard the hazard
When working at height is essential, ensure that workers are not exposed to unnecessary risks; consider providing a parapet or guardrail to eliminate the fall hazard.
3. Protect the worker
Where it is not possible to eliminate the risk of falling, use suitable fall protection system to minimise the consequences of a fall. This can be achieved with a fall arrest or fall restraint system–two completely different entities.
In essence, a fall restraint system prevents workers from reaching a hazard, while a fall arrest system allows workers to reach a hazard and then protects them if they should fall.
These systems allow a person access to conduct their duties but prevent them from reaching a point where a fall could occur.
Fall Restraint systems are generally suitable if the person needs to work at the edge of a hazard. For example, where there is a need to maintain gutters along the edge of a roof, or if there are other potential fall hazards such as a fragile roof, roof lights or air vents.
If fitting a fall restraint system, it is recommended that the system should be tested to fall arrest loads to ensure a person’s safety in situations where the system may be misused (i.e. when the person using it wears an over-length lanyard to enable access to the edge of a roof).
Restraint systems are generally positioned more than 2 m from the hazard. This is because common practice is for the worker to be connected to the system by a fixed length 1.5 m lanyard.
A fall arrest system provides maximum freedom of movement for workers to conduct their duties. In doing so it allows them to reach the point where a fall could occur, such as the edge of a roof for gutter maintenance. However, in the event of a fall, the fall will be arrested and so allow the person to either effect a self-rescue or be rescued.
Following a fall, consideration must be given to the rescue of the worker – in fact, there is a legal obligation to have a full and comprehensive rescue plan in place when individuals are working at height.
Using ladders safely
place the base of the ladder on a firm, level, dry surface. If there’s a time when this isn’t possible – working on grass, for instance – tie the feet of the ladder to stakes in the ground to stop it slipping, and place a large flat wooden board underneath to help prevent it sinking.
put a ladder on top of boxes, bricks, barrels or any other unstable surface just to gain extra height.
position the ladder so that the base won’t slip outwards. Leaning ladders are designed so that their safest angle of use comes when every 1 measure out from the wall is matched by 4 measures up it (rungs are usually about a third of a metre apart, so its easy enough to get the distances roughly right). Most new extension ladders now have a mark on the stiles to show the safest angle of leaning.
Remember the rule: ‘ONE OUT FOR FOUR UP’
The more the base is moved out from this position, the greater the risk that it will slip outwards suddenly and fall down without warning!
secure the bottom and the upper part of the ladder, by tying them (from stiles, not rungs) with rope or straps onto a stable , fixed object. You can tie the base to stakes in the ground, or use fixed blocks or sandbags to help guard against the ladder slipping, or buy special stabilisers. A rope or strap tied from a stile onto a fixed object at about the height of the fifth rung from bottom will help to stop any further movement.
If it’s impossible for some reason to secure the ladder, get another adult to ‘foot’ it (by standing with one foot on the bottom rung and holding a stile in each hand).
rest the top of the ladder against a solid surface, never against guttering, or other narrow or plastic features. Where a surface is too brittle or weak to support the top of the ladder, use a stay or a stand-off resting on a firm surface nearby. Bolt or clip this to the top of the ladder before putting up the ladder.
have at feast three rungs extending beyond a roofs edge if you’re using a ladder to get yourself up onto the roof.
make sure that longer extension ladders (over 18 rungs) have an overlap of at least three rungs. Shorter ones (up to 18 rungs) need a minimum overlap of two.
keep your body facing the ladder at all times, centred between the stiles.
reach too far forwards or sideways, or stand with one foot on the ladder and the other on something else.
move the ladder to avoid overstretching, and re-secure it whenever necessary, however frustrating that might be!
try to keep both hands free to hold the ladder as much as possible while you’re climbing or descending – if you need to carry any tools, use a shoulder bag, belt holster or belt hooks.
carry heavy items or long lengths of material up a ladder.
hold on to the ladder with one hand while you work. You can get special trays which fit between the stiles to take paint pots, tools etc.
wear strong, flat shoes or boots, with dry soles and a good grip.
wear sandals, slip-ons or have bare feet on a ladder.
make sure a door is locked, blocked or guarded by someone if you’re up a ladder in front of it.
use a ladder in a strong wind.
use a ladder near any power lines.
be tempted to use a ladder if you’re not fit enough, or suffer from giddiness or aren’t confident with heights.
Here are the main reasons why people choose aluminium ladders:
· High tensile strength
· Zero level thermal stress
· Low maintenance required
· Can withstand weather extremities
Post by Indian Safety Association