Ground Support Tower

[dombrown]

Hi there,

I am looking for any previous experience with the best way of building something to achieve this:

 

I need to construct a tower, 10m high, outdoors that will be left for a couple of months unsupervised.

 

I am thinking truss would be the best material to build this, but I am wondering rough base widths and how many. Also, guy ropes would be a must I am sure!!

 

Thanks in advance

 

Dom

[dunk_1984]

What is the tower for? Then someone can point you in the direction of a suitable solution provider.

[ImagineerTom]

//opens can of worms//

 

If you have to ask the most basic questions like "how could I do this" then you're not going to be the one qualified to sign off on this; you need to be looking at a third party to design/install/certify this for you.

As mentioned precisely "what" you need to hold up there has an impact on the methodology used.

To also be pedantic it would also be almost impossible and certainly reckless to leave such a tower "unattended" - this sort of temporary construction is designed to be checked every few days but more importantly is very attractive to people to climb and meddling fingers to un-bolt; if left un-supervised it would be only a matter of hours before it's gone to a scrap yard or fallen over because someone thought they'd fiddle with the guy-ropes.

[Seano]

I am thinking truss would be the best material to build this

 

Probably (though depending on what you want scaffolding may be an option), but you don't want to be trying to re-invent the wheel yourself. Whether you hire or buy, you need an experienced and reputable supplier to build the thing for you.

 

Also, guy ropes would be a must I am sure!!

 

Possibly, but not necessarily. Guy ropes (that extend to ground-anchors beyond the base) are not routinely used on stand-alone towers (for pa, followspots etc. associated with outdoor gigs) - but your definition of "unsupervised" may have a bearing on that. If you're unable to have contingency plans to react quickly to bad weather, you'll need a structure built to withstand more challenging conditions than would normally be the case for a short-term temporary structure.

[Jivemaster]

This will ALWAYS need designing by competent professionals, but one critical feature of the design is the available base area and base material. A 10M tower on a 10m square concrete base is a different design from one on a 2m patch of wet earth. Get the dimensions and ask for help. ANY provider will expect you to secure the structure against theft, so unattended is unacceptable, it might be gone one time!

[dombrown]

If you have to ask the most basic questions like "how could I do this" then you're not going to be the one qualified to sign off on this; you need to be looking at a third party to design/install/certify this for you.

I suppose I should have been expecting the usual Blue Room negativity.

 

The reason I am asking is that I am looking to see if anyone has done this sort of thing in the past. If someone would like to volunteer to baby sit the tower for the aforementioned 2 months, then feel free. Otherwise, the safety and anti theft features that will be added to the final design will have to do.

 

The tower is a central point to rig strings of fairy lights to that will be run to the ground in a circle around the tower.

 

The ground is soil and this will be placed in the center of trees. There will be about 10m around the tower that will be hidden from sight.

 

The idea of guy ropes are to withstand any weather eventualities.

[timsabre]

If it's only holding up fairy lights, that puts a bit of a different perspective on it... it sounded like a more significant construction

 

If I was doing this I would just hire in a ground support tower. Most staging companies would have this off the shelf along with suitable ballasting or guying.

I would also try asking local scaffolding companies as they are quite good at coming up with solutions to this sort of thing, though the results are often not very pretty.

[ImagineerTom]

I'm not really sure it counts as negativity when simply reminding you of the law and the ramifications of getting this wrong, especially when it's from someone who does exactly what you're trying to do several times a week....

 

to answer your other questions:-

 

The reason I am asking is that I am looking to see if anyone has done this sort of thing in the past.

Yes, hundreds of people have put up comparable sized towers thousands of times in this country alone.

If someone would like to volunteer to baby sit the tower for the aforementioned 2 months, then feel free.

If you can't afford to do it safely and properly then you can't afford to do it, the cost of the tower being stolen or falling on someone is far in excess of the cost of supervising it properly

Otherwise, the safety and anti theft features that will be added to the final design will have to do.

would this be the design that has not yet been done? On a professional level I'd be very keen to hear what features you're adding to an UNSUPERVISED tower that makes it anti-topple and anti-theft; I'm struggling to think of anything you could do that couldn't be defeated by a determined idiot or a thief with a battery powered angle-grinder and a 4x4 in 10 mins. It's a serious question - what are you going to do 'cause I could introduce you to a lot of people who'd pay handsomely for such a solution.

The tower is a central point to rig strings of fairy lights to that will be run to the ground in a circle around the tower.

So (in laymans terms) basically a christmas-tree type setup or a cone of light? The actual weight required to rig from it is what - 50kg maximum?

The ground is soil and this will be placed in the center of trees. There will be about 10m around the tower that will be hidden from sight.

There's no such ground type as "soil" - there's 101 soil types each one with different characteristics that will impact the design.

How much space is there between this object and the trees, normally such towers are assembled on the ground and then "hinged" up so (allowing for guy ropes etc) you need a completely clear space at least 10m x 8m and ideally 20m x 8m to allow you room to use a mechanical lifting system properly.

Can you better define what you mean by "10m around the tower hidden from sight" - that sentence alone doesn't actually make sense.

 

The idea of guy ropes are to withstand any weather eventualities

I refer you to my opening argument - the guy ropes are doing a lot of stuff that's nothing to do with the weather, there are circumstances where guy-ropes (improperly spec'd) could make the tower more prone to weather-related problems. There's also no such thing as a temporary structure that can "withstand any weather eventualities"

If you can be more specific in your specification then there's plenty of people who can help and even do the job for you; if you're going to just take pot-shots and provide vague information then there's absolutely nothing anyone can do to help.

t

[AHYoung]

Get in touch with the local scaff co and get a quote. Scaffolding is actually fairly cheap and they know what they are talking about when it comes to temporary structures. They will also build it in a remarkably quick fashion and will do all the nonesense sorry paperwork that the local authorities will require as thats what they do and they deal with this on a daily basis. You could maybee make a big flagpole out of truss and guy it off, why ive got not idea as to the loadings or inclination to find out, but it still means that you have an access problem which says to me that a 10m scaff based tower that you can climb internally is the best option. but again ive got no idea which is why id get the guys local to you that that do know to supply.

[dombrown]

There's no such ground type as "soil" - there's 101 soil types each one with different characteristics that will impact the design.

How much space is there between this object and the trees, normally such towers are assembled on the ground and then "hinged" up so (allowing for guy ropes etc) you need a completely clear space at least 10m x 8m and ideally 20m x 8m to allow you room to use a mechanical lifting system properly.

Can you better define what you mean by "10m around the tower hidden from sight" - that sentence alone doesn't actually make sense.

 

From person experience, which may not compare to yours, soil is a type of ground. It is some what different to concrete. If you would like to list the 101 types of soil and their characteristics, I could perhaps narrow it down.

 

There is a 10m radius around the center point of the tower where any base would be out of site of the public.

 

would this be the design that has not yet been done? On a professional level I'd be very keen to hear what features you're adding to an UNSUPERVISED tower that makes it anti-topple and anti-theft; I'm struggling to think of anything you could do that couldn't be defeated by a determined idiot or a thief with a battery powered angle-grinder and a 4x4 in 10 mins. It's a serious question - what are you going to do 'cause I could introduce you to a lot of people who'd pay handsomely for such a solution.

 

This would be part of the design when we have decided on the tower is self. I would like to assume that towers that are supervised are naturally anti-topple. I would be pretty peeved if I hired in towers for a flown array and they toppled over...

The safety features, including the fact that the display is in a non pedestrian area will also be decided upon the results of the risk assessment.

And I can let you into a secret about a design I have come up with where by you can suspend a light fitting on a tower in public place and the theft rate is very low. I call it a lamp post...

 

the guy ropes are doing a lot of stuff that's nothing to do with the weather

 

What stuff are the guy ropes for if not to do with the weather?

 

 

If you can be more specific in your specification then there's plenty of people who can help and even do the job for you; if you're going to just take pot-shots and provide vague information then there's absolutely nothing anyone can do to help.

Yes, hundreds of people have put up comparable sized towers thousands of times in this country alone.

I don't see how I am taking pot shots when I simply asked if people have had similar experiences in the past? If there are hundreds of people that have done this in this country alone, why is it such an issue with mine?

 

Get in touch with the local scaff co and get a quote. Scaffolding is actually fairly cheap and they know what they are talking about when it comes to temporary structures. They will also build it in a remarkably quick fashion and will do all the nonesense sorry paperwork that the local authorities will require as thats what they do and they deal with this on a daily basis. You could maybee make a big flagpole out of truss and guy it off, why ive got not idea as to the loadings or inclination to find out, but it still means that you have an access problem which says to me that a 10m scaff based tower that you can climb internally is the best option. but again ive got no idea which is why id get the guys local to you that that do know to supply.

 

Hi AHYoung,

 

Many thanks for your constructive response. We will be onsite with a cherry picker so access is no problem. My concern with the platform tower idea would be the size, it would be very visible. That's why I like the flag pole idea. I wanted to know a rough base size that I would need to create to make this effective, any ideas?

 

Dom

[Seano]

I suppose I should have been expecting the usual Blue Room negativity.

 

Funny, I was just thinking there'd been rather less of "the usual Blue Room negativity" than I'd have expected.

 

Get in touch with the local scaff co and get a quote.

 

Now that he's (kinda sorta) described the application, it's pretty obvious that scaff is not likely to be a good option.

From the OP, I was thinking something along the lines of a single masted ground support pa tower, but I don't think that's the way to go either.

Actually what he wants is basically a Christmas tree.

 

Rather than scaffolders or staging/rigging companies, the OP might be better off talking to telegraph pole installers. (Many of which also install municipal Christmas decs.)

 

Bit outside of the BR's remit, that, though some of the larger summer festivals do have timber telegraph poles installed temporarily here and there.

[dombrown]

Rather than scaffolders or staging/rigging companies, the OP might be better off talking to telegraph pole installers. (Many of which also install municipal Christmas decs.)

Bit outside of the BR's remit, that, though some of the larger summer festivals do have timber telegraph poles installed temporarily here and there.

 

Hit the nail on the head there. I was wanting a more surface mounted option, but I think I am going to have to go with an installed solution.

 

Thanks Seano

[Seano]

From person experience, which may not compare to yours, soil is a type of ground. It is some what different to concrete. If you would like to list the 101 types of soil and their characteristics, I could perhaps narrow it down.

 

Or you could read a book. Failing that even just check out wikipedia. Start here maybe: http://en.wikipedia.org/wiki/Geotechnical_engineering

 

I would like to assume that towers that are supervised are naturally anti-topple. I would be pretty peeved if I hired in towers for a flown array and they toppled over...

 

Besides being secured (yes, by supervision) against tampering and/or theft, contingency plans are put in place to deal with extreme weather. This may include lowering suspended loads, evacuating the area - whatever. But it's another aspect of the supervision - someone needs to be on site to monitor the conditions and react accordingly.

 

I don't know if you read the news much, but temporary structures have been known to fall over when they're not planned and supervised properly. People died.

 

In the absence of that contigency planning, monitoring and supervision the temporary structure would need, in effect, to meet the same specification as a permanent structure.

 

And I can let you into a secret about a design I have come up with where by you can suspend a light fitting on a tower in public place and the theft rate is very low. I call it a lamp post...

 

You invented the lamp post? Awesome.

By an odd coincidence, before I read your last post I had effectively just suggested you get a lamp post installed. I know you think you're being sarcastic, but seriously, it could well be your best option.

[ImagineerTom]

From person experience, which may not compare to yours, soil is a type of ground. It is some what different to concrete. If you would like to list the 101 types of soil and their characteristics, I could perhaps narrow it down.

<br style="color: rgb(28, 40, 55); font-size: 13px; line-height: 19.5px; background-color: rgb(250, 251, 252);">

There are MANY different types of soil and each have very different properties - a light sandy soil is crap for pull-out loads but very forgiving in wet conditions. A clay based soil has bog problems with bridging (go look up sink-holes) which is a problem for the point loads but it's amazingly good for pull-out loads; I could go on....

There is a 10m radius around the center point of the tower where any base would be out of site of the public

that's much more helpful information, that gives you lots of room for guy-ropes or even a base HOWEVER we are suddenly talking about a lot more metal which instantly makes it a much more attractive target for theft.

This would be part of the design when we have decided on the tower is self. I would like to assume that towers that are supervised are naturally anti-topple. I would be pretty peeved if I hired in towers for a flown array and they toppled over...The safety features, including the fact that the display is in a non pedestrian area will also be decided upon the results of the risk assessment.

I'm struggling to think of any temporary structure (especially not 10m tall ones) that are ever left un-supervised and aren't intended to be actively maintained and adjusted in response to the forces that act upon them.

And I can let you into a secret about a design I have come up with where by you can suspend a light fitting on a tower in public place and the theft rate is very low. I call it a lamp post...

ohhhh, so whilst we're talking about temporary structures you're talking about a permanent structure that is (literally) concreted in to the ground. Somewhat ironically even if we ignore this little error I do have to point out that modern lamp-posts aren't made of metal any more (because of the theft/scrap value as well as the damage caused when they fall down) and even permanently installed ones aren't actually left unsupervised; they're actually inspected surprisingly frequently and cost a lot more money than you think because they've been professionally designed.

What stuff are the guy ropes for if not to do with the weather?

oh dear... Vibration, the installation process, support from physical intervention. The vibrations caused by wind turbulance around wrongly-spec'd guy ropes can start putting some serious strain on your tower; guys tensioned wrongly or at the wrong angle can sevearly compromise your tower's stability - just "adding guy ropes" doesn't automatically make a structure better; again they need to be properly designed and spec'd with this specific situation in mind.

I don't see how I am taking pot shots when I simply asked if people have had similar experiences in the past? If there are hundreds of people that have done this in this country alone, why is it such an issue with mine?

Hundreds of people take knives, slice complete strangers open and perform surgery on their vital organs inside. None of these things are an issue if done by people who know what they're doing and who have had appropriate training and understanding of the situation they're involved in. As I have already alluded to and other have said more bluntly; you need to get an expert in to do this for you as "some bloke I found on an internet forum" isn't going to be able to give you the necessary knowledge and experience to enable you to do this job yourself.

That's why I like the flag pole idea. I wanted to know a rough base size that I would need to create to make this effective, any ideas?

I'd want a base of at least 5m radius to be reasonably sure that it couldn't self topple from "day to day" influences. As said previously though the bigger issue is stopping people stealing bits of it or attempting to climb it; both of which dramatically effect it's stability and are far and away the biggest problem you have to overcome on this project.

If stability of the structure isn't a big issue then a flagpole made of scaff-pole fixed to the ground with putlocks and a ring of guy ropes would be the easiest to implement but the top of the pole would have around 400mm of horizontal movement and the structure itself wouldn't be terribly pretty. A big-top king pole with guys would give you a more substantial structure that would be about as "solid" as you could possibly want but are made out of very attractive steel which WILL get stolen if left unsupervised (no-one would give you insurance) and which would be much much easier for people to climb or sabotage. Some sort of truss ground-support system could give you a tower that's more self contained and which comes with lots of ready-made calculations but being made of aluminium it'll be stolen within hours of being left unsupervised, could be very easily climbed, is very easy to topple. ALL of these solutions would be very dependent on the guy-ropes - just cutting/releasing/damaging one of them would be a major problem that required an intervention.

[paulears]

Moderation: A number of members have expressed their concern about the rather abrupt and snappy style of posts in the past few weeks. Some, we are simply removing, but many do have some useful information hidden - but the pointless requites of quotes, with less than helpful comments do not help the s/n ratio.

 

The endless repetition of "Danger Will Robinson", while obviously sensible when all the facts are in simply is not appropriate in many cases - and while some warnings are completely valid, others assume a level of skill to be missing, which clearly in some cases, is not correct. We want to promote safety, but there are ways of doing it that are less abrasive.

 

We have quality standards and they apply to everyone. We have often in the past made the comment that if you cannot be nice, don't post at all. If you have a serious safety concern, then why not send the member a PM? This removes the duelling that seems to take place so frequently. Based on comments the mods receive, this kind of behaviour is found very objectionable - so please don't do it. Be nice and phrase posts in an appropriate manner. I'm working in a school today and the blue room is banned for the students, and I had to get a special log in to be able to access our site. This is very sad, but the IT people have pretty clever software now that reads forums and decides if they should be on the not suitable for kids list.

 

So please - can we stop the endless squabbles?

Paul Mods

 

Just a thought on the topic, but for something like this, maybe our events type truss is the wrong product? What the OP wants might well be a comms type tower. Designed for exactly what he wants to do - support something heavy, for a longer period, with the facility to take side forces that are dynamic. Fixed and telescopic versions are available - some even trailer mounted. Guy ropes and/or self-supporting types. Designed to be used in high winds, with heavy and long cables going out to other structures or other towers.

 

This link shows some quite different products to our truss - designed for what the OP wants.

 

http://www.radiostructures.com/images/uploads/Trailer_Masts_016.jpg

 

If you want it to be more permanent, then the options are proper concrete base, and no guy ropes on a rigid 10m tower - which is very common, or a less substantial bass but guy ropes. The trailer versions can be hired, rigid self-supporting towers are less hireable because of the transport costs and erection issues. Quite a few types have a hinge bass. Lattice towers for comms use seem a much more sensible product for this kind of use.