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Kansas State is one of the first facilities to utilize barrier jackets for media attention.

A Wind - Wind Situation

By Murray Bilby

This article will address the issue of wind resistance on temporary portable railings such as steel barricades, and the related issue of how wind can influence the stability of the barrier by using accessories such as jackets, banners, covers, and signs.

As with standard frames, proper utilization
and planning can allow the high frames to be
used effectively even in windy areas.

Background
Steel barricades (as well as plastic variations) are well established as an effective crowd management tool. Most public assembly facilities maintain an inventory of steel or plastic barricades.

Increasingly, signage is being attached to barricades. Messages or images through signage can increase an event’s safety by providing patrons with directions, rules, or other information. Additionally, barrier jackets or banners often work as advertisements by featuring the logo of an organization or sponsor.

Blowing In The Wind
Messages on jackets, banners, or metal signs demonstrably add value to a portable barricade. However, there is an issue – albeit a minor one – regarding whether these accessories add wind resistance, thus making a barrier more susceptible to tipping over in windy conditions.

If a sailboat can still race with torn sails, then we need to make a similar analogy to a free standing barrier. Adding additional resistance with signage will clearly be an influence.

This is a concern that any facility or event manager should be aware of when planning to utilize steel or plastic barricades (and their corresponding jackets) in high-wind situations. But the addition of a jacket, banner, or sign to a barrier is only one factor which impacts the stability of these barricades in windy conditions. Here is a rundown of other factors which also play large roles in ensuring the wind-stability of barricades.

The Wind Factors
The Product: First and foremost, barriers can – and sometimes do – blow over. It is inherent in the product. Steel barriers are designed to be temporary railings, easy to set up and take down. At most locations, barriers are more likely to be used individually, or in short non-connected lines, rather than being hooked together in longer interconnected lines (like the traditional Mardi Gras parade lines). A running line of frames improves stability, but even when hooked together, barriers can still be knocked down by heavy winds.

Quality:
Barriers of differing qualities exist, even though differences (some of which are done for cost-cutting reasons) may not be easily noticed from a photograph. Variations can include different materials (steel, plastic, aluminum), weights, diameters, height, and tubing styles.

Center of Gravity: Plastic barricades, as well as some new steel barrier variations, have higher centers of gravity than traditional steel barricades. While these styles offer some advantages, stability is not one of them.

Base Style Factors
a) Square stacking variations: Inherent in the design of square stacking barriers is a single pivot point where the tubing edge meets the ground. With less ground contact, when the wind blows, the top can arch over and fall sooner than would be the case with other base styles.

The main ticket entrance of Radio City Music
Hall includes several hundred barriers to help
stage visitors on both sides of the building.

Additionally, some square stacking variations have just a 9-inch spread between ground contact points. Traditional frames (including the Blockader square stacking unit) have 24 inch spreads, yet are still susceptible to wind gusts. The higher the center of gravity the wider the base needs to be.

b) Barriers with traditional base on one end; single tube (insert) on other: This style has advantages in handling and cost reduction. However, when struck with a strong gust of wind, this style in lengths over 4 feet will tend to turn over more easily than even the square stacking variation, because one end will only have the width of the tube (1.5 inches or less) touching the ground.

c) Traditional bridge bases: The traditional double bridge base style, with its egg-shape ground contact points, remains the most popular style and represents half the market. This is due in large part to its stability.

d) Flat bases: Flat bases also provide stability, because they will tend to slide, rather than tip over. Rubber inserts increase ground friction by adding more resistance. Flat bases are most effective in wind, because they can be anchored to the ground through holes via tent pegs.

However, flat bases have a tendency over time to curve at the neck, creating a rocking chair effect. Handling flat base barriers with care (especially avoid dropping them from a height to the ground) will give these bases longer effective life-span.

Real Stability Solutions
To alleviate any concerns about the stability of temporary railings in windy conditions, here are the most practical steps a facility or event can take:

1) Use high-quality barriers and bases.
Get to know the industry standards for barrier quality, and understand the advantages and disadvantages of the various base styles. Traditional bridge bases, and flat bases, are the styles that provide the most stability in wind.

2) Place your barriers in zig-zag arrangements. A zig-zag line creates more ground resistance and wider base support. We have been told that this solution has been successfully utilized at helicopter pads.

Here is an example of correctly sandbagged
units with signage.

Wind cuts can be unobtrusive when spaced
around printed text in reducing resistance.

3) Add anchors or sand-bags to barriers. When it comes to reducing the force of the wind, this is a time-tested option to improve stability and decrease the risks of barriers tipping over.

Wind Cuts?
A banner, jacket, or sign adds additional resistance to wind and can increase the risk that a barrier will blow over. But because of the misconception that this is a significant stability factor, some barricade owners have inquired about the possible advantages of wind cuts (sometimes also called half-moon cuts) to their jacket or banner.

Wind cuts are only a minimally effective solution to any potential wind stability problem. First, the vertical uprights of the barrier will prevent most cuts from opening properly, and unless cuts are perfectly aligned on both sides of a jacket, any wind that does get through will be trapped between the two sides.

In addition to not working on a practical level, cutting a banner, jacket or sign defeats its purpose. Images or messages will no longer be attractive and effective if they are riddled with holes.

Consequently, we do not suggest or promote wind cuts on the jackets we design and market. We will do it on request – at no additional charge – but we always encourage more effective solutions.

Conclusion
Jackets, banners, or metal signs expand the utility of portable railings. Steel barriers can serve their intended crowd management role, while a jacket’s ability to convey messages on a barrier has proven to be a great communication and marketing tool for many facilities.

The addition of such covers to a barricade is one of several factors in contributing to the barrier’s possible instability in windy conditions. The most effective way to ensure barrier stability in windy conditions is to make sure you use quality barriers and bases, plan the proper arrangement of your barriers to adapt to the conditions.

Murray Bilby is president of The Tamis Corporation, supplier of Blockader barricades and accessories (including custom-fit barrier jackets). For more details and illustrations, an expanded version of this article will soon appear on the blockader.com Website.

 

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