Rolling Gates & Chain Link Fence

[AZengineer]

Does anyone know of any refernces for specification and design of rolling gates?

I have a project wth a 12' tall x 24' wide chain link rolling gate - the kind with plastic or metal slats interwoven with the fence - so it is essentially a solid surface which collects a lot of wind load. The typical conditiona that I have seen consists of two horizontal galvanized post "tracks" that support a pair of rollers, in conjunction with a ground level roller at the opening end of the gate. It does not seem that this condition would provide an adequate lateral connection, especially for the wind loads prescribed by ASCE 7-05, section 6.5.14.

The Chain Link Fence Manufactures institute publishes a useful reference in the design of the fence, but does not seem to address gate connections, specifically rollers or latches.

 

[msquared48]

Seems to me that the only time you would have to worry about the overturning/lateral load, and I assume normal to the gate, would be when it is being opened or closed. Other than this time, the gate is either protected (open), or seated to the end post (closed).

Are you concerned about the gate being able to span the 24" as a beam?

Mike McCann
McCann Engineering

 

[AZengineer]

I am not concerned about the gate when it is open. When it is closed, it spans horizontally to each side, and will push the rollers sideways against the tracks. I am seeking the capacity of the roller/track connection, as well as the capacity of whatever latching mechanism is used at the other end to secure it to the end post of the fence.

I can size the horizontal members as necessary to act as a horizontal beam.

 

[msquared48]

OK. Whats the tallest vehicle you want to allow to enter the premises? If the limit is 14 feet, can you put another guide over the top of the gate, say above the 14' level, with a roller in a vertical spring to maintain good ground contact? Just a thought... Might look funny, but could work.

Mike McCann
McCann Engineering

 

[AZengineer]

Not a bad idea, but I'm not sure that's addressing the question I have... Let me describe the project in more detail. It's actually different than how I described it but I simplified it for the specific question I had.

I have a 12' tall masonry wall surrounding a cell phone tower site. There is a 12' wide opening (I said it was 24' wide to emphasize the wind load contrbuting to the jambs) in it so that maintenance vehicles can gain access to the site. In this opening, there is a sliding gate (it's actually tube steel with metal slats). On the end of the gate that slides open behind the masonry wall, there is a wheel on the top and bottm that slide along tracks that are mounted to the masory wall. On the other end, there is a wheel that slides along the ground. The architectural drawings do not provide details showing how the wheels are attached to the gate or how the gate is attached to the wall on the latching side, it simply says "provided by contractor".

Assuming that the gate can adequately resist the wind loads, it will induce horizontal reactions at each jamb on either side of the openings. I can design the masonry wall and the gate to resist these loads, but I am not aware of any design aids or manufacturer's data that specify what horizontal loads the rollers are capable of sustaining. I think your suggestion about putting another track over the opening is intended to provide another track so that two rollers can sandwich the gate between them. This can be done with the tracks that are mounted on the wall without the need for an overead track, but I still need to know how to determine exactly what lateral load this connection would be capable of sustaining.

 

[unclesyd]

Here is the Tymetal gate website. I seen a lot of their gates installed. They may have some information that you need as they make about every kind imaginable.
I don't know the extent of regulations but there are requirements that prevent entrapment in an operating gate. I know the last two I saw had the rollers enclosed to eliminate a pinch point.