Static vs. Kinetic Testing

 

This is not ladder safety

This is not ladder safety

Ladders go through numerous safety tests, but these tests have their shortcomings.

The Test Lab

All official testing and certification methodologies, including ANSI, EN-131, CSA, NZ-AUS, and MIL, are performed with motionless, static weights that exert force in only one direction. These tests are performed in a controlled environment with perfect conditions, on flat level ground, with no external factors, usually in a testing lab. Each test is designed to determine the strength of certain areas of the ladder and requires a test load of up to 4 times the rating of the ladder. All Little Giant products meet or exceed these requirements.

Ladders in the Real World

Static force gauges do not have families waiting for them to come home at the end of the day. If people remained perfectly motionless on a ladder, they might be safe but they wouldn’t get much done. Static weights do not make decisions, good or bad. People sometimes take risks or get distracted or startled. Job sites are notorious for uneven, pitted, and unstable ground.

Operators Don’t Follow the Instructions

Understanding these differences, Little Giant has studied the way people actually use their ladders and designed around or against human behavior. It’s human nature to overreach, or to use the closest ladder, even if it’s the wrong kind; or to stand on the top rung or top cap instead of finding a taller stepladder. Even with the best training, we know operators will cut corners to save time and energy.

The Human Body Is Not Static

Ordinary ladders are not designed to keep an operator from falling, but simply to counteract the vertical force of gravity and elevate the operator above the ground. But every move an operator makes exerts forces on the ladder that it is not designed to take. Simple actions like stepping off an extension ladder to a roof or shifting your weight can destabilize an ordinary ladder. Involuntary responses like swatting at a bee or reaching out to catch a falling tool also exert lateral forces that can destabilize a ladder.

Responsible Design

For decades ordinary ladder manufacturers have known about the inherent safety risks of their products and done nothing. Isn’t it ironic that basically every piece of heavy equipment you see on a jobsite has outriggers or stabilizers to prevent kinetic forces from destabilizing it. Yet, we send unprotected operators dozens of feet in the air on ordinary ladders that are no wider than they are. Some of the most catastrophic, fatal accidents occur because ordinary ladders have this inherent risk built into their design.

One ladder company actually attempts to profit from these design flaws by marketing fall-arrest equipment to protect operators when they fall from their own inherently unsafe ladders. Little Giant would rather focus on designing ladders that prevent the fall in the first place.

 

Be Safe on the Job

OSHA and MSHA are the two primary government agencies responsible for authoring and enforcing workplace safety regulations.

The Story

A fire alarm technician was inspecting the fire alarms at a care center when he climbed an extension ladder, provided by the care center. He fell from the ladder,  breaking both feet and suffering other orthopedic injuries. In his spine, he also suffered a compression fracture in his spine.

The Technician’s View

In court, the technician argued that the maintenance supervisor who set up the ladder for him had done it incorrectly. He also said the maintenance supervisor had not inspected or maintained the la, violating OSHA regulations.

The Care Center’s View

The care center argued the accident was the worker’s fault for not being properly trained and that the care center was not to blame for the worker not returning to work.

The Court Decision

After 10 days in trial and two days in deliberations, the court sided with the worker. The care center had to pay him for damages, lost wages, past medical costs and furture medical costs.

This case gives us a few reminders. First, OSHA protects workers at their own company as well as at companies they visit. Second, ladder safety is important for employees as well as visitors. Always inspect your ladder before you use it and before youlet others use it. Also, train your team and any other visitors who will be using a ladder on how to use the ladder safely.

Self-Employed Man Suffers Fatal Injury

imgID52404521.jpg-pwrt3A man in England was working on a ladder outside  a house when he fell. He was brought to the hospital where he died eight days after the accident.

The accident happened when the ladder slipped, knocking him to the ground.

Unfortunately, this accident could have been prevented, and this man’s life could have been saved.

If the ladder had been at the correct angle and if he had had someone to hold thee base, the ladder would not have slipped and the man would most likely still be alive.

Often, we don’t realize how important that correct angle is. A ladder should be set up at a 75.5 degree angle. There are two easy ways to check the angle. The first is to download the ladder app from NIOSH and follow the instructions for proper ladder set up. The second is to follow the “Four-to-one ratio rule.” The ladder should be one foot away from the wall for every four feet of ladder. So, if the ladder is 16 feet tall, it should be four feet away from the wall.

Firefighter Falls from Ladder

Lincolnton Fire Department Capt. Joe Fletcher (right) with his son, Parker, 4, and his father, Boger City firefighter Louis Fletcher, courtesy of Michelle T. Bernard.

Joe Fletcher was hired full-time as a firefighter with the Lincolnton, North Carolina Fire Department when he was 20, was promoted to engineer a few years later and was promoted as captain 2016. Last November, he fell from his ladder while working on his gutters. The ladder moved, knocking him onto his deck, on the top of his backpack leaf blower.

“I got my senses together and did a quick self-check to see if I could get up but I had pretty extreme pain in my lower back so I knew I had done something but I wasn’t sure of the magnitude of what I’d done,” he said about the accident. “Thankfully, I had my cell phone in my back pocket and I called the fire station. Probably because he recognized my number, the assistant chief picked up the phone. I told him that I had fell from my roofline and I was hurt and needed someone to come and help me.”

Within minutes, his fellow firefighters arrived. Fletcher thought he just needed help standing up, but quickly realized the injury was more severe when he got a sharp pain up his back. He was transported the hospital strapped on a backboard to keep him from injuring himself more.

Two days after the accident, Fletcher had a surgery to put two rods on the outside of his backbone with four screws on each side. The rods were used to stabilize a lower back fracture. He then had physical therapy for three weeks.

Just before Christmas, Fletcher returned to work on light duty. He had to the fire department on light duty the week before Christmas, and was on light duty. In June, he had another surgery to remove the rods and screws and another three weeks of physical therapy. He was on light duty for a little while more and returned to his regular job on Aug. 8.

While Fletcher said that it never really crossed his mind that he wouldn’t be able to return to work, he was afraid that he would not be as good as he once was.

“I pretty much stayed in the mindset that I was coming back,” he said. “At 28 years old, I’m an eight-and-a-half-year veteran here in Lincolnton but, in my opinion, it’s way too early to end my career. So far it’s going good.”

We are glad this accident had a better outcome than some, but this accident most likely could have been prevented. The accident happened when his ladder slipped. The most common causes of a ladder slipping are setting the ladder at the wrong angle, using the ladder on a wet or slippery surface, or using a ladder with worn feet. The good news is that each of these causes can easily be prevented. Set your ladder at a 75.5 degree angle. Make sure the ground is dry before you climb. Replace worn ladder feet.

We are glad this firefighter was able to recover. Remember to climb safe!

The Truth About Ladder Racks

8527147250_a544f86135_bA few years ago, we did some research about ladder racks and the pros and cons of using them. Here’s what we found out:

Ladder Racks: Cost and Consequences

Most service technicians who need ladders for their work use some sort of ladder rack on their work truck or van. Research done by the School of Aerospace, Mechanical and Manufacturing Engineering in Melbourne, Australia found that increases the amount of drag and required fuel. The ladder load also increases greenhouse gas emission and can affect the vehicle’s stability.

The Experiment

They conducted this study by using  identical vehicles that traveled the same distance at the same average speed. The researchers evaluated the drag, fuel consumption and greenhouse gas emissions.

Drag and Fuel Consumption

The ladder rack required a 30 percent increase in power to overcome the drag. The faster the vehicle travels, the more power is needed to overcome the drag. This increase in power usage leads to an increase in fuel costs.

Safety

Ladder racks also affect the vehicle’s stability. The rack moves the center of gravity, affecting how the vehicle is driven. Shifting aerodynamics and crosswinds can change quickly and increase the chance of roll-over accidents.  

Greenhouse Gas Emission

The control vehicle with no vehicle add-ons emits approximately 14 lbs of CO2 each year.  The same vehicle travelling the same distance with a roof rack and ladder attached will emit approximately 442.36 lbs of CO2.

Conclusions

We don’t have a perfect solution to the problem this research presents. If possible, transport your ladder inside your vehicle to decrease the drag and other issues the ladder rack brings. If not possible to put your ladder in your work truck, be aware of the dangers and issues of using the rack and look out for a better solution.

 

 

Source:

http://bsmeicte2012.iutoic-dhaka.edu/proceedings/13th-acfm-2010/contributed/aeroaconstics/319.pdf

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