Good morning I represent Serious Stages, we have been building covered stages, temporary building and specialist structures since 1985.

We currently construct over 400 large structures, approximately 200 ourselves and the remainder in conjunction with our partners in Australia – Butlers Hire, the Middle East – Al Laith, Spain - Esenario's. These structures vary considerably and we have recently been involved in the construction of the Opera House temporary stage in Sydney Harbour, a stage built into the harbour with the seating and VIP areas built into the bank.

Last December we designed and built a 150m wide screen, 40m high for a Vangelis showcase event in front fo the entire Royal family of Qatar. We've just completed the Soundwave tour of 4 Australian cities and before that we did the Big Day Out which is a twin stage festival that tours round 6 cities in 3 weeks. SLIDE AUSTRALIA We also cover many major festivals in the UK as well as being heavily involved in a variety of projects concerning a major sporting event taking place in the UK this year. SLIDE VANGELIS
Whilst building these structures we run into varying problems. Two major issues in particular stick out. Considerable production loads are often applied to our structures and quite often the actual rigging loads are only given to us relatively late in the day, in many cases on the day of load in. This can be a cause for concern and whilst we ensure that any loads that our systems carry are within the design limits, having advance knowledge of the rigging weights and detailed plans would be incredibly helpful.

The second issue we have is the differing interpretations we find on what effective wind speed the structure has to be designed to, issues which we run into time again both in the UK and globally.

The wind blows all over the planet and it's always fascinating how engineers and authorities in the various countries seem to deal with temporary structures in varying ways. We have recently built a roof in Orlando, USA. The structure was a tower roof, 20 m high, fully sheeted with 2 goal posts PA and Video supports. As the Orlando authorities admitted when looking at our documentation, we were the first stage they had certificated in 16 years and, despite having a vibrant entertainment industry which required numerous stages being built every year, they had not seen fit to certify the engineering of any of the stages. There is now a realisation after the much reported accidents that took place recently in the USA and Canada that these structures vary so markedly that each has to be checked within the local guidlines. SLIDE ORLANDO

In Dubai they require an 18m/s wind speed, Germany tends to require 20m/s, Australia varies from 20 m/s– 36m/s. The manner in which checking or certifying structures is carried out varies considerably, both in the UK and Globally. Some of the larger local authorities have extremely good in house engineers who engage with our engineers, do detailed checks on the calculations and follow this up by site visits, meeting engineers on site before signing off the structure. Ireland requires the client to hire independent structural engineers to achieve a similar function as larger local authorities. Germany requires stringent detailed analysis of all aspects of the structure, unless the supplier has a proof book. This proof book is where a specific constructed stage is authenticated as being structurally correct by the TUV , which is an organisation that have state and federal approval and can certify the safety of the product. If the supplier has a proof book the local engineer will merely inspect the stamps and check the structure is built in accordance with the drawings which form part of the proof book. If everything is in order and up to date, the structure can be signed off based on the fact that the TUV have done all the detailed analysis beforehand.

In our case an engineer from the TUV spent 4 days inspecting our manufacturing processes and inspecting our welding quality and checks. This was done prior to us undertaking a tour with the system in 18 cities in Germany.

We are a service company and I believe we need to provide a service to our clients which allows them to be comfortable with our products. When people buy a ticket to an event or attend a free event they do not expect to put their lives at risk due to the structures that have been erected at the event location. Unfortunately, within the last year there have been a series of accidents where structures failing in extreme weather conditions have caused fatalities which is a human tragedy and incredibly sad. In conjunction with colleagues, actually competitors but I believe the HSE who have set up a working group (emails Gavin Bull credit him) the section being dealt with Gavin Bull- are endeavouring to create a best practice which the leading companies in our sector will create abide and follow to ensure a high standard which can then be relied upon by those clients who choose to use the services of one of these companies.

The design of stages is not a subject that is clear to our collective clients. When you buy a car you feel relatively reassured that you do not have to check that it will not function in the way you expect it to as it is meticulously supervised and regulated. The same cannot be said for temporary structures. There is obviously guidance and British Standards but there are considerable gray areas and a variety of different approaches from companies to the way they deal with the structural engineering. It would seem sensible to try and provide a uniform and agreed criteria, with no room for doubt or differing interpretation. This would entail agreeing, where possible, standard co-efficients, reserve factors and effective wind speeds.

Generally speaking, the structures we and the larger companies within our industry build are subject to design calculations, independent checking and built by highly trained and experienced staff, and the structure is signed off by a suitably competent person. However, as the slide show, looking at a snapshot of our industry we can see the variations in the design wind speed used by companies for their structures. SLIDE WIND SPEEDS

There is sometimes some confusion as not everybody knows what 25m/s translates to in miles per hour or kilometres per hour or in fact what that means. The Beaufort scale usefully describes in lay-mans terms what wind speed means and is a very useful guide as it is indicative of what those figures mean . SLIDE BEAUFORT The other factor which may confuse people is that it is not a direct proportion of load to wind speed, roughly speaking a 25m wind speed has a load dynamic pressure 60% higher than a 20m wind speed. SLIDE DYNAMIC PRESSURES

I'd like to just mention at this point in time I am not an engineer, I'm aware there are several engineers in the room and I'm just hoping i have my facts correct – I'm sure if I haven't I will be corrected quite quickly!

Many of these temporary structures are subject to Wind Management Plans, which is an area of slight doubt for me, especially in relation to staging. Guidance on this has been given by the institute of structural engineers document on temporary demountable structures, which is an excellent document. It specifies that demountable structures should be designed to a wind speed of 25m/s but advise that under a wind management policy sheets can be removed at lower wind speeds to enable the structure to still be in place at 25m a second? SLIDE WIND MANAGEMENT

There are 2 factors which relate to this, one is that it is difficult and dangerous to extract sheets if they are under load from wind pressures of 15 – 20m a second. It is virtually impossible to replace those sheets in similar wind speeds or in fact if wind speeds are in excess of 10m/s. So it's all very well having a wind policy that states you will remove the sheets at a particular wind speed, but the practicality of doing so is severely questionable. You would also require substantial number of crew to achieve this task and since the object of the stage is to facilitate a show, any sheet which is removed would need to be reinstalled as quickly as possible to allow that show to continue. This, as I mentioned, would be extraordinarily difficult.

The second issue is that the object of the covered sides of the stage is to protect the performers from the wind and quite often the rain that accompanies the wind. If there was no need for the side sheeting then it would not be there, my point being that the side sheeting is extremely important to the function of the stage therefore it's removal is in itself a threat to the performance. It therefore seems important that the stage has integrity, a full rigging load and it's full complement of sheeting at a wind speed of between 20 – 22m a second. There will probably be a vigorous debate amongst my colleagues about what limit should be set - I am personally in favour of 22m/s because it removes any confusion. SLIDE WIND MAP
  • Inspection
Ø Each truss tagged. Know fabricator and life of truss
Ø Scaffold inspected and tagged in numbered stillages. Logged on system
Ø During fabrcication die tests of welds etc
  • Training
Ø Using construction industry training inspectors to view our process
Ø All crew getting CSCS card
Ø Continual forks / cherry / crane rigging banksman
  • Scenario wind management
Ø Wind is rising to say 15m/s
Ø Possibly sheets to be removed
Ø Who stops the show? Who is liable for the cost? Who has the final say on whether the structure is safe?
  • Actual case wind management
Ø Could the sheets be removed at high speed. Doors and low level yes, but large side and back walls?
Ø Is there enough standby crew to remove and reinstall after the wind dies down
  • Questions
Ø What level of wind do you expect your stage to operate in
Ø How much ballast has been provided
  • Solutions?
Ø Voluntary code that gives a standard wind speed that a fully sheeted stage must be able to cope with?
Ø Perhaps 22ms fully rigged and fully sheeted.
Ø Further wind management that does not require the removal of large panels (ie doors and small infill sheets can be removed