Another look at door costs and safety

A recent article on "Exposing the hidden costs at door openings" (PE, July 1999, p 66, File 5040) highlighted several points regarding the safety features of high-speed roll-up doors.


A recent article on "Exposing the hidden costs at door openings" ( PE , July 1999, p 66, File 5040) highlighted several points regarding the safety features of high-speed roll-up doors. Our company would like to clarify these points, and bring out some additional factors regarding door safety not addressed in the article.

The referenced article includes the following comments.

"Perhaps the most significant hidden cost tied to doors is the potential for work-related injuries. With the prevalence of hard, bottom-bar technology of conventional high-speed roll-up doors, workers are at risk of serious injury. In fact a hard-edge bottom bar, even equipped with a reversing feature, impacts with a downward force in excess of 150 lb/sq in."

We feel these statements include imprecise data, while omitting other relevant information that would serve to give readers a more complete and accurate view regarding the many advanced safety features fundamental to modern high-speed roll-up door technology.

The high-speed roll-up door has emerged as not only the most economical choice of industry today, but has proven to be exponentially safer than previous technologies.

In fact, virtually all roll-up door advancements are safety driven. Today, roll-up doors often feature clear plastic strips in the fabric, which provide see-through visibility on both sides of the door. The fabric itself is often manufactured in choices of bright, easy-to-see colors that help prevent operator accidents. In addition, many models of advanced roll-up doors employ technology that detects any object in the door's path, reversing it immediately to prevent impact. This technology assures the maximum safety of operators and equipment.

Not mentioned in the article is the fact that some doors do not possess a reversing capability. Soft bottom-edge doors stop only when coming into actual contact with whatever or whoever is below the door. For this reason, a high-speed door equipped with advanced reversing technology may be a better choice for safety.

Concerning the stated downward force of 150 lb/sq in., we feel this is not possible. A door would have to weigh about 9 tons to induce this much pressure. In reality, most models of roll-up doors exert less than 1 lb/sq in. of pressure.

To conclude, we concur with one of the article's central topics: Safety is a major concern with any door technology. Leading manufacturers of these doors place great emphasis on the safety issue. Never before have industrial doors offered such a precision combination of safety, reliability, performance, and long-term cost savings.

-- Matthew R. Nelson, Marketing Director, Albany Intl.

Author's reply: We agree that high-speed roll-ups first offered a superior alternative to conventional doors when they were introduced around 15-yr ago. Since that time, many adaptations to high-speed roll-up doors have been required to respond to the safety needs of the workplace. For example, vision panels were added to improve the line of sight at high traffic openings, reversing edges were built onto metal bottom bars to prevent entrapment, and photo eyes were incorporated to help prevent closure on people and/or equipment in the opening itself.

But we take exception to the claim that 9 tons is required to create a 150-psi impact. Dynamic impacts produce peak forces significantly greater than the static weight of the object itself. In testing, a 2.5-lb. book dropped from 24 in. created a peak dynamic impact force of over 200 lb. Testing has also shown that some conventional hard-edge doors can develop peak dynamic impact forces in excess of 1000 lb. We believe that our statement of hard-edge bottom bar impacts "in excess of 150 lb. sq in." is indeed the current reality, and actually a conservative measurement.

Still, original high-speed roll-up door technologies continue to focus on downward impacts and entrapment concerns without addressing their metal bottom bar. From a safety standpoint, downward impacts and entrapment are a real concern. However, lateral impacts, which occur more often, need to be addressed, as do secondary impacts resulting from flyaway bottom bars, doors reversing upward upon impact, and potential entanglement with coil cords, cables, etc.

While many adaptations have been made to conventional, high-speed roll-up doors, their basic design remained unchanged until the entire concept was reevaluated. This change resulted in soft-bottom edge technology, elimination of external electronics, internal curtain retention methods, and many other enhancements to help address the safety, performance, and durability concerns of the past.

A high-speed door system is just that -- a system of integrated features designed to provide the user optimum performance. When looking to address openings as efficiently and safely as possible, a facility is faced with numerous, and sometimes confusing, options. It is important that the user is aware of the technological advances in the high-speed door industry that now provide a total system approach to productivity and personnel safety.

-- Kevin King, National Sales Manager, Rite-Hite Doors, Inc.

The Top Plant program honors outstanding manufacturing facilities in North America. View the 2015 Top Plant.
The Product of the Year program recognizes products newly released in the manufacturing industries.
Each year, a panel of Control Engineering and Plant Engineering editors and industry expert judges select the System Integrator of the Year Award winners in three categories.
Pipe fabrication and IIoT; 2017 Product of the Year finalists
The future of electrical safety; Four keys to RPM success; Picking the right weld fume option
A new approach to the Skills Gap; Community colleges may hold the key for manufacturing; 2017 Engineering Leaders Under 40
Control room technology innovation; Practical approaches to corrosion protection; Pipeline regulator revises quality programs
The cloud, mobility, and remote operations; SCADA and contextual mobility; Custom UPS empowering a secure pipeline
Infrastructure for natural gas expansion; Artificial lift methods; Disruptive technology and fugitive gas emissions
Power system design for high-performance buildings; mitigating arc flash hazards
VFDs improving motion control applications; Powering automation and IIoT wirelessly; Connecting the dots
Natural gas engines; New applications for fuel cells; Large engines become more efficient; Extending boiler life

Annual Salary Survey

Before the calendar turned, 2016 already had the makings of a pivotal year for manufacturing, and for the world.

There were the big events for the year, including the United States as Partner Country at Hannover Messe in April and the 2016 International Manufacturing Technology Show in Chicago in September. There's also the matter of the U.S. presidential elections in November, which promise to shape policy in manufacturing for years to come.

But the year started with global economic turmoil, as a slowdown in Chinese manufacturing triggered a worldwide stock hiccup that sent values plummeting. The continued plunge in world oil prices has resulted in a slowdown in exploration and, by extension, the manufacture of exploration equipment.

Read more: 2015 Salary Survey

Maintenance and reliability tips and best practices from the maintenance and reliability coaches at Allied Reliability Group.
The One Voice for Manufacturing blog reports on federal public policy issues impacting the manufacturing sector. One Voice is a joint effort by the National Tooling and Machining...
The Society for Maintenance and Reliability Professionals an organization devoted...
Join this ongoing discussion of machine guarding topics, including solutions assessments, regulatory compliance, gap analysis...
IMS Research, recently acquired by IHS Inc., is a leading independent supplier of market research and consultancy to the global electronics industry.
Maintenance is not optional in manufacturing. It’s a profit center, driving productivity and uptime while reducing overall repair costs.
The Lachance on CMMS blog is about current maintenance topics. Blogger Paul Lachance is president and chief technology officer for Smartware Group.
The maintenance journey has been a long, slow trek for most manufacturers and has gone from preventive maintenance to predictive maintenance.
This digital report explains how plant engineers and subject matter experts (SME) need support for time series data and its many challenges.
This digital report will explore several aspects of how IIoT will transform manufacturing in the coming years.
Maintenance Manager; California Oils Corp.
Associate, Electrical Engineering; Wood Harbinger
Control Systems Engineer; Robert Bosch Corp.
This course focuses on climate analysis, appropriateness of cooling system selection, and combining cooling systems.
This course will help identify and reveal electrical hazards and identify the solutions to implementing and maintaining a safe work environment.
This course explains how maintaining power and communication systems through emergency power-generation systems is critical.
click me