zhongxinladder

Cages for Fixed Ladders
The requirements for cages for fixed ladders are as follows:
 Horizontal bands must be fastened to the side rails of rail ladders or directly to the structure, building or equipment for individual-rung ladders. Vertical bars must be on the inside of the horizontal bands and must be fastened to them.
 Cages must not extend less than 27 inches (68 cm), or more than 30 inches (76 cm) from the centerline of the step or rung and must not be less than 27 inches (68 cm) wide.
 Insides of cages must be clear of projections.
 Horizontal bands must be spaced at intervals not more than 4 feet (1.2 m) apart measured from centerline to centerline.
 Vertical bars must be spaced at intervals not more than 9.5 inches (24 cm), measured centerline to centerline.
 Bottoms of cages must be between 7 feet (2.1 m) and 8 feet (2.4 m) above the point of access to the bottom of the ladder. The bottom of the cage must be flared not less than 4 inches (10 cm) between the bottom horizontal band and the next higher band.
 Tops of cages must be a minimum of 42 inches (1.1 m) above the top of the platform or the point of access at the top of the ladder. There must be a way to access the platform or other point of access.

Wells for Fixed Ladders
The requirements for wells for fixed ladders are as follows:
 Wells must completely encircle the ladder.
 Wells must be free of projections.
 Inside faces of wells on the climbing side of the ladder must extend between 27 inches (68 cm) and 30 inches (76 cm) from the centerline of the step or rung.
 Inside widths of wells must be at least 30 inches (76 cm).
 Bottoms of wells above the point of access to the bottom of the ladder must be between 7 feet (2.1 m) and 8 feet (2.4 m).

Ladder Safety Devices and Related Support Systems for Fixed Ladders
The connection between the carrier or lifeline and the point of attachment to the body belt or harness must not exceed 9 inches (23 cm) in length. In addition, ladder safety devices and related support systems on fixed ladders must conform to the following:
 All safety devices must be able to withstand, without failure, a drop test consisting of a 500-pound weight (226 kg) dropping 18 inches (41 cm).
 All safety devices must permit the worker to ascend or descend without continually having to hold, push or pull any part of the device, leaving both hands free for climbing.
 All safety devices must be activated within 2 feet (.61 m) after a fall occurs and limit the descending velocity of an employee to 7 feet/second (2.1 m/sec) or less.

Requirements for Household ladder Safety Devices for Fixed Ladders
The requirements for mounting ladder safety devices for fixed ladders are as follows:
 Mountings for rigid carriers must be attached at each end of the carrier, with intermediate mountings spaced along the entire length of the carrier, to provide the necessary strength to stop workers’ falls.
 Mountings for flexible carriers must be attached at each end of the carrier. Cable guides for flexible carriers must be installed with a spacing between 25 feet (7.6 m) and 40 feet (12.2 m) along the entire length of the carrier, to prevent wind damage to the system.
 Design and installation of mountings and cable guides must not reduce the strength of the ladder.
 Side rails and household step ladders or rungs for side-step fixed ladders must be continuous in extension.

Defective Ladders
Ladders needing repairs are subject to the following rules:
 Portable ladders with structural defects—such as broken or missing rungs, cleats or steps, broken or split rails, corroded components or other faulty or defective components—must immediately be marked defective or tagged with "Do Not Use" or similar language and withdrawn from service until repaired.
 Fixed ladders with structural defects—such as broken or missing rungs, cleats or steps, broken or split rails or corroded components— must be withdrawn from service until repaired.
 Defective fixed ladders are considered withdrawn from use when they are immediately tagged with "Do Not Use" or similar language, or marked in a manner that identifies them as defective, or blocked—such as with a plywood attachment that spans several rungs.
 Ladder repairs must restore the ladder to a condition meeting its original design criteria before the ladder is returned to use.

from:osha.gov

 Use non-self-supporting ladders at an angle where the horizontal distance from the top support to the foot of the ladder is approximately one-quarter of the working length of the ladder.
 Use wooden ladders built at the jobsite with spliced side rails at an angle where the horizontal distance is one eighth of the working length of the ladder.
In addition, the top of a non-self-supporting ladder must be placed with two rails supported equally unless it is equipped with a single support attachment.

Aluminum step ladder
 Do not use the top or top step of a stepladder as a step.
 Do not use cross bracing on the rear section of stepladders for climbing unless the ladders are designed and provided with steps for climbing on both front and rear sections.
 Metal spreader or locking devices must be provided on step ladders to hold the front and back sections in an open position when ladders are being used.

Portable Ladders
The minimum clear distance between side rails for all portable ladders must be 11.5 inches (29 cm). In addition, the rungs and steps of portable metal ladders must be corrugated, knurled, dimpled, coated with skid-resistant material or treated to minimize slipping. Non-self-supporting and self-supporting portable ladders must support at least four times the maximum intended load; extra heavy-duty type 1A metal or plastic ladders must sustain 3.3 times the maximum intended load. To determine whether a self-supporting ladder can sustain a certain load, apply the load to the ladder in a downward vertical direction with the ladder placed at a horizontal angle of 75.5 degrees.
When portable ladders are used for access to an upper landing surface, the side rails must extend at least 3 feet (.9 m) above the upper landing surface. When such an extension is not possible, the ladder must be secured and a grasping device such as a grab rail must be provided to assist workers in mounting and dismounting the ladder. A ladder extension must not deflect under a load that would cause the ladder to slip off its supports.

Fixed Ladders
If the total length of the climb on a fixed ladder equals or exceeds 24 feet (7.3 m), the ladder must be equipped with ladder safety devices; or self-retracting lifelines and rest platforms at intervals not to exceed 150 feet (45.7 m); or a cage or well and multiple ladder sections with each ladder section not to exceed 50 feet (15.2 m) in length. These ladder sections must be offset from adjacent sections and landing platforms must be provided at maximum intervals of 50 feet (15.2 m). In addition, fixed ladders must meet the following requirements:

 Fixed ladders must be able to support at least two loads of 250 pounds (114 kg) each, concentrated between any two consecutive attachments. Fixed ladders also must support added anticipated loads caused by ice buildup, winds, rigging and impact loads resulting from using ladder safety devices.

 Individual rung/step ladders must extend at least 42 inches (1.1 m) above an access level or landing platform either by the continuation of the rung spacings as horizontal grab bars or by providing vertical grab bars that must have the same lateral spacing as the vertical legs of the ladder rails.

 Each step or rung of a fixed ladder must be able to support a load of at least 250 pounds (114 kg) applied in the middle of the step or rung.
 Minimum clear distance between the sides of individual rung/step ladders and between the side rails of other fixed ladders must be 16 inches (41 cm).
 Rungs of individual rung/step ladders must be shaped to prevent slipping off the end of the rungs.
 Rungs and steps of fixed metal ladders manufactured after March 15, 1991, must be corrugated, knurled, dimpled, coated with skid-resistant material or treated to minimize slipping.

 Minimum perpendicular clearance between fixed ladder rungs, cleats, and steps and any obstruction behind the ladder must be 7 inches (18 cm), except that the clearance for an elevator pit ladder must be 4.5 inches (11 cm).
 Minimum perpendicular clearance between the centerline of Ladder stabilizer , cleats and steps, and any obstruction on the climbing side of the ladder must be 30 inches (76 cm). If obstructions are unavoidable, clearance may be reduced to 24 inches (61 cm), provided a deflection device is installed to guide workers around the obstruction.

 Step-across distance between the center of the steps or rungs of fixed ladders and the nearest  edge of a landing area must be no less than 7 inches (18 cm) and no more than 12 inches (30 cm). A landing platform must be provided if the step-across distance exceeds 12 inches (30 cm).
 Fixed ladders without cages or wells must have at least a 15-inch (38 cm) clearance width to the nearest permanent object on each side of the centerline of the ladder.
 Fixed ladders must be provided with cages, wells, ladder safety devices or self-retracting lifelines where the length of climb is less than 24 feet (7.3 m) but the top of the ladder is at a distance greater than 24 feet (7.3 m) above lower levels.

 Side rails of through or side-step fixed ladders must extend 42 inches (1.1 m) above the top level or landing platform served by the ladder. Parapet ladders must have an access level at the roof if the parapet is cut to permit passage through it. If the parapet is continuous, the access level is the top of the parapet.
 Steps or rungs for through-fixed-ladder extensions must be omitted from the extension; and the extension of side rails must be flared to provide between 24 inches (61 cm) and 30 inches (76 cm) clearance between side rails.
 When safety devices are provided, the maximum clearance distance between side rail extensions must not exceed 36 inches (91 cm).
 Fixed ladders must be used at a pitch no greater than 90 degrees from the horizontal, measured from the back side of the ladder.

from:osha

The following rules apply to all ladders:
 Maintain ladders free of oil, grease and other slipping hazards.
 Do not load ladders beyond their maximum intended load nor beyond their manufacturer’s rated capacity.
 Use ladders only for their designed purpose.
 Use ladders only on stable and level surfaces unless secured to prevent accidental movement.
 Do not use ladders on slippery surfaces unless secured or provided with slip-resistant feet to prevent accidental movement. Do not use slipresistant feet as a substitute for exercising care when placing, lashing or holding a ladder upon slippery surfaces.
 Secure ladders placed in areas such as passageways, doorways or driveways, or where they can be displaced by workplace activities or traffic to prevent accidental movement. Or use a barricade to keep traffic or activity away from the ladder.

 Keep areas clear around the top and bottom of ladders .
 Do not move, shift or extend ladders while in use.
 Use ladders equipped with nonconductive side rails if the worker or the ladder could contact exposed energized electrical equipment.
 Face the ladder when moving up or down.
 Use at least one hand to grasp the ladder when climbing.

 Do not carry objects or loads that could cause loss of balance and falling. In addition, the following general requirements apply to all ladders, including ladders built at the jobsite:

Double-cleated ladders or two or more ladders must be provided when ladders are the only way to enter or exit a work area where 25 or more employees work or when a ladder serves simultaneous two-way traffic.
 Ladder rungs, cleats and steps must be parallel, level and uniformly spaced when the ladder is in position for use.
 Rungs, cleats and steps of portable and fixed ladders (except as provided below) must not be spaced less than 10 inches (25 cm) apart, nor more than 14 inches (36 cm) apart, along the ladder’s side rails.

 Rungs, cleats and steps of step stools must not be less than 8 inches (20 cm) apart, nor more than 12 inches (31 cm) apart, between center lines of the rungs, cleats and steps.
 Rungs, cleats and steps at the base section of extension trestle ladders must not be less than 8 inches (20 cm) nor more than 18 inches (46 cm) apart, between center lines of the rungs, cleats and steps. The rung spacing on the extension section must not be less than 6 inches (15 cm) nor more than 12 inches (31 cm).

 Ladders must not be tied orfastened together to create longer sections unless they are specifically designed for such use.
 When splicing side rails, the resulting side rail must be equivalent in strength to a one-piece side rail made of the same material.
 Two or more separate ladders used to reach an elevated work area must be offset with a platform or landing between the ladders, except when portable ladders are used to gain access to fixed ladders.
 Ladder components must be surfaced to prevent snagging of clothing and injury from punctures or lacerations.

    These rules specify when employers must
provide stairways and ladders. In general, the
standards require the following:
 When there is a break in elevation of 19 inches(48 cm) or more and no ramp, runway,embankment or personnel hoist is available,employers must provide a stairway or ladder at all worker points of access.

 When there is only one point of access between levels, employers must keep it clear of obstacles to permit free passage by workers.If free passage becomes restricted,employers must provide a second point of access and ensure that workers use it.

 When there are more than two points of access between levels, employers must ensure that at least one point of access remains clear.In addition, employers must install all stairway and ladder fall protection systems required by these rules and ensure that their worksite meets all requirements of the stairway and ladder rules before employees use stairways or ladders. See 29 CFR 1926.1050-1060 for the details of the standard.

Note: The standard does not apply to ladders specifically manufactured for scaffold access and egress, but does apply to job-made and manufactured portable ladders intended for general purpose use. Rules for ladders used on or with scaffolds are addressed in 29 CFR 1926.451 Subpart L.

*  First and foremost! Look for any electrical power lines and keep away from them.
          o Near where you are proposing to work.
          o Near where you are raising the ladder.
          o Near you if you have to carry the ladder in it's raised position say around a corner.
    * Make sure the ladder is in good condition.
    * One ladder, one person only on it at the same time. Don't get your mate to bring stuff up to you.
    * Always make sure that the ladder is on a firm base.
    * Make sure it is strong enough for the job.  Ladders have weight ratings on them.  I disobeyed this simple rule once on a step ladder.  I was lifting up a 9" x 3" hardwood beam, and the back frame of the Aluminum step ladder collapsed under me.  No warning.  The beam nearly took my ear off.  (I could have spent the rest of my life looking like Vincent Van Gogh :-)
    * Always have the ladder at least three rungs or say 1 meter higher than the roof edge, to give you support as you step on and off.
    * Never step on any of those higher rungs though, use the one lower than the edge to get onto and off the roof.
    * If you are working on a wall, keep the top three rungs for your hand grip, don't stand on them, get a longer ladder if you can't reach.
    * For extension ladders use the manufacturer's recommendations for minimum lap. Personally I hate to see ladders stretched out to their maximum.  I always go for extra strength that more lap gives.  If your ladder is not long enough, NEVER EXTEND IT PAST THE RECOMMENDED LAP! Go out and hire a longer one.
    * Don't over stretch out on a too short ladder. It is dangerous and apart from that it is not efficient.  If you are drilling, you want to be pushing at just about chest height, not stretching above your head.  Simple logic. 
    * When I was into sailing an old saying was "one hand for the boat and one hand for yourself". The same thing applys to ladders also, always have three points of contact with the ladder, two feet plus one hand, or if stepping off the ladder onto the roof two hands and one foot.
    * The ladder can be roped at the top and bottom if nescessary, but tie the ropes to the sides and not the rungs.
    * On sloping ground don't just pack up one leg with something. This is dangerous as the spring of the ladder can move it off the packer.
    * Make a definate provision for a solid base by either leveing the ground and providing a sole plate or if on sloping concrete provide a decent sized piece of ply to rest a leg on, then secure the base with ropes.

foot of a ladder
ladders - Swivel the bottom of the ladder fittings inwards and then bounce on the bottom rung to dig them into the ground.
top of ladder secured to a gutter with multigrips
ladders - Top of ladder clipped to a gutter with multigrips.  I should have put a rag or something inbetween to stop the ladder marking the gutter.  Naughty!

    * On firm ground like the lawn on the right, flip the base pieces to the inside of the ladder and jump on the bottom rung a couple of times to dig the pointy bits in. If the ground is softer provide a good sized timber sole plate.
    * If the top feels a bit insecure I have also partly unscrewed a couple of roof screws, used tie wire to fix the top of the ladder to them and then screwed them down again.
    * The photo shows an occaision where I clipped the top of the ladder to the gutter using multigrips to stop it sliding as I was carrying tools onto the roof.
    * Never put anything at the bottom that can cause you to trip as you get off the ladder.  I have seen a couple of star pickets used for holding the bottom rung.  More danger of stepping on them than what they are trying to stop.
    * Don't tread mud and crap onto the rungs, (and then onto the roof too).  Clean your feet first.
    * There is a term called "walking a ladder". This does not refer to carrying the ladder vertically from one place to another but it means that when on the top of the ladder you wrigle it sideways to extend your reach (say when painting gutters). DON'T DO IT! sooner or later you will reach a point of no return. In addition you put all the weight on one leg of the ladder which could cause other problems.

from:builderbill-diy-help

There are three basic portable ladder types:

    * Type I – Industrial Ladder: heavy-duty with a load capacity not more than 250 pounds.

    * Type II – Commercial Ladder: medium-duty with a load capacity not more than 225 pounds. (Suited for painting and similar tasks.)

    * Type III – Household Ladder : light-duty with a load capacity of 200 pounds.

There are many types of ladders available on the market. If it is intended to be portable and used by a single person, it should fit into one of the three basic categories.

It is rare that you just go up and down a ladder.  You use it to do a job, so you could be carrying tools and materials up it.  You could be on it and be sawing or drilling.  You can apply many kilograms of thrust to the ladder, over and above your own weight when you are working on it, so you need a solid support.

As far as I know ladder rungs are set at 1 foot apart.  So an 18 pin (rung) ladder is 18ft long, plus a bit.  A double 18 pin extension will get you safely onto a 28 ft high roof.  Say four rungs overlap at the join, three rungs over the top and a foot or so for the slope.
extension ladder safety
ladders - correct position.

On the right is a sketch of an extension ladder leaning on a roof edge.

The angle of the ladder to the vertical is important.  Four to one is the recommended angle ratio.

Note! In nearly 50 years up and down ladders I have never done any sort of measurement for this.  Always I've done it by eye and what feels right.  Having said that, when I was taking the photo below, earlier today I decided to set the ladder at 4:1 ratio and straight away it felt too steep for me.  I needed a bit more out from the wall to feel comfortable.  Just my opinion, but you have to work with what feels right.

If you have it too steep, as you are climbing up it the top tends to skitter about or feel loose.  There is not enough weight resting on the roof edge.

If you place it with too much angle, the bottom is liable to slide out, but more importantly you are making the ladder itself carry too much of your weight instead of the ground.  Also you will be leaning at an unnatural angle as you climb.

Inspect ladders regularly. household step ladders and extension ladders should be inspected for broken or frozen joints or latches. Aluminum ladders should be inspected for cracks and broken welds. Aluminum ladders should also be inspected for rough spots and burrs before first use.

Wood ladders should be inspected for cracked wood, splinters, and rot. Look for broken or loose hardware. Protect wood ladders with linseed oil or clear sealant. Never paint a wooden ladder - the paint may hide imperfections such as rot or cracks.

Fiberglass ladders are protected with a clear sealant. If the fiberglass is damaged through the sealant, sand lightly before applying another coat of lacquer. 

from:townhall|ladder

Rigid ladders were originally made of wood,but in the 20th century Aluminum step ladder became more common because of its lighter weight. Ladders with fiberglass stiles are used for working on or near overhead electrical wires, because fiberglass is an electrical insulator.

For safety, a rigid ladder should be leaned at an angle of about fifteen degrees to the vertical. In other words, the distance from the foot of the ladder to the wall should be about one quarter of the height of the top of the ladder. At steeper angles, the ladder is at risk of toppling backwards when the climber leans away from it. At shallower angles, the ladder may lose its grip on the ground. Ladder stabilizer are available that increase the ladder's grip on the ground.

A ladder standoff, or stay, is a device fitted to the top of a ladder to hold it away from the wall. This enables the ladder to clear overhanging obstacles, such as the eaves of a roof, and increases the safe working height for a given length of ladder.

    * Rope ladders are used where storage space is extremely limited, weight must be kept to a minimum, or in instances where the object to be climbed is too curved to use a rigid ladder. They may have rigid or flexible rungs. Climbing a rope ladder requires more skill than climbing a rigid ladder, because the ladder tends to swing like a pendulum. Steel and aluminum rope ladders as sometimes used in vertical caving.

    * Dissipative ladders are portable ladders built to ESD (Electrostatic Discharge) standard. Electrostatic Discharge is a natural occurrence in which electricity is passed through our body, or other conductor, and discharges onto some object. For example, the shock we feel when we touch a doorknob is an ESD. This natural occurrence is becoming a very hot topic in the field of electronics assembly due to the costly damage ESDs can cause to sensitive electronic equipment. Dissipative ladders are ladders with controlled electric resistance: the resistance slows the transfer of charge from one point to another, offering increased protection during ESD events: ≥105 and < 1012 Ω / square>

    * Pool ladders. A ladder is also used on the side of a boat, to climb into it from the water, and in a swimming pool. Swimming pool ladders are usually made from plastic steps with special grip and metal bars on the sides to support the steps and as handrails for the user.

    * Assault ladders. These are designed to be used by units which may need to board or assault vessels or buildings. They can be used when a full sized ladder is not required or when working in confined spaces. Suited for covert operations such as sniper placement, and vessel boardings. It was developed and designed for tubular assaults including buses and trains and for first story breaching. Its extra wide design gives the user greater stability, but still can fold away to be stored. It is available in standard Aluminum Ramp or non-reflective black finish in 6 and 8 foot lengths.

from:wiki|Aluminum step ladder