By: Kristopher J. Seluga, PE
Tel: (203) 329-9909
Email: Technology Associates
There are over 100,000 ladder accidents annually in the U.S. requiring hospital emergency room treatment. Although many of these result from user misuse, such as an improper extension ladder lean angle against a wall causing it to slip outward, use of a damaged ladder, or failing to lock a step ladder's spreaders, many ladders fail due to design or manufacturing defects. Many are designed too flexibly and some extension ladders are equipped with inferior rung locks. Other defects can be introduced during manufacturing such as material flaws or improperly seated rivet attachments. In addition, the fine-print warnings and instructions, on most ladders, are hard to read.
We are active participants on the ANSI Ladder Standards Committee and have:
Through scientific analysis, we can help you answer pertinent questions such as:
Falls From Stepladders:
We have investigated numerous stepladder accidents involving unexplained falls where no obvious structural defect can be found. When a ladder is too flexible, a climber may inadvertently cause the rear legs to shift sidewise, raising one of the legs off the ground. Later, when the user shifts his weight, the raised leg suddenly strikes the ground causing him to loose his balance and fall. In several cases, we have demonstrated how modest side rail stiffness improvements can reduce this problem.
Extension Ladder Slips off Low Pitch Roof:
A handyman was repairing some siding on a split-level roof when the extension ladder he had placed on the lower roof slid out from under him. We demonstrated that the modest slant of the lower roof produced a significant tendency for the lower side rail legs to slide out, and that the posted warnings against such action were present on the incident ladder. This resulted in a successful homeowner's claim defense.
Kristopher J. Seluga, PE, is a Mechanical Engineering, Accident Reconstruction, Biomechanics, and Safety Expert with over 20 years of experience. He received his Bachelor's and Master's degrees from the Mechanical Engineering department at MIT where he worked on the development of novel three-dimensional printing technologies. Mr. Seluga is also a licensed Professional Engineer in New York and Connecticut, and has served as a member of the ANSI engineering committee for the Z130.1 and Z135 standards for golf cars and PTV's. His research interests and peer reviewed publications span the topics of Motor Vehicle Dynamics, Product Safety, and Biomechanics.
©Copyright - All Rights Reserved
DO NOT REPRODUCE WITHOUT WRITTEN PERMISSION BY AUTHOR.
7/31/2009· Accident Investigation & Reconstruction
Forensic Engineering Experts: Construction
Construction sites and equipment present many hazards if proper care is not taken. The space in and around a construction site is often filled with potentially dangerous, high-powered equipment capable of delivering high forces.
7/22/2009· Accident Investigation & Reconstruction
Forensic Engineering Experts: Whiplash
A car is stopped for a light when it is unexpectedly rear-ended causing little or no damage to either vehicle. Nevertheless, the passengers of the struck vehicle complain of neck, shoulder and back pain. Insurance claim representatives, attorneys, medical, engineering and biomedical experts are then brought in and various conflicting allegations, testimony and opinions are expressed.
2/14/2014· Accident Investigation & Reconstruction
Automated Retrieval System Failure Results in Catastrophic Fire at Storage Facility
By: Bill O'Donnell
The largest storage rack/ retrieval system, larger than two football fields and eighty feet wide was constructed to store 108 million pounds of paper products. On July, 2002, after two months of use, the facility collapsed and sparked a fire that destroyed the entire structure and 45 million pounds of paper. Nearly 50 fire departments responded to the inferno, which burned for three weeks. The owner of the facility sued a number of companies that included the contractor that designed and built the structure, a subcontractor, and the company that supplied the 110 foot steel columns.
