This is all 220m of the Gate Towers building currently under construction in Abu Dhabi. We are providing a modular suspended platform of both tension netting and the WEB Deck rigid platform system as a temporary work platform replacing hanging scaffolding. The WEB system was chosen as it is faster to install and more lightweight than scaffolding.
Tension Netting (also referred to as Work Position Platform Nets or Walk on Nets) is a working platform constructed from nets. Tension netting can be considered when access is required to difficult areas such as a high level atrium or production areas with short shutdown periods. It is lightweight when compared to scaffolding, can be fast to install and remove and is versatile. It is suitable for light duty tasks such as, inspection, surveying and painting.
What Standards Apply?
It is important to note that currently there is no EN Standard in place for Tension Netting. Systems that conform to EN 1263 should not be considered, as this is a standard that applies only to Fall Arrest safety nets and therefore is totally meaningless in this application.
Who can work from Tension Netting?
Anyone who has received ‘work at height’ awareness training.This is one of the unique benefits of our system, your operatives can work from it in fall arrest, and we install the safety lines for you. Furthermore we can supervise the use of the system if required.
Who installs Tension Netting?
Tension Netting is typically installed by rope access. It is important to understand that installing tension netting correctly requires properly trained technicians who have undergone full training. more complex scenarios you will need to have installers with have specialist-rigging skills needed to install the wire rope supports in complex situations. Our installers are fully trained and familiar with the rigging of tension netting.
Why Polyester Nets?
There is a huge variation in types of nets from materail to cell size. We prefer to specify Polyester nets with 40mm cell size. We prefer polyester chiefly because it has a remarkably high burst strength compared to other net material, 3.5mm-495kg 5mm-1100kg. When loaded it produces minimal stretch 0.5%, this makes for a more stable working surface and is less tiring to move around on, we chose knotted nets to aid traction under foot. Other benefits of polyester are its resistance to water, which ensures that the system remains at a constant weight, improved resistance to contaminants such as chemical and paint.
We specify a 40mm mesh size, as this will capture small hand tools and equipment and provide a secure foot hold. Any larger than 40mm mesh size means that the operative’s foot could go through the mesh.
What documents will be needed?
* The design drawings and calculations for approval.
* A task/site specific Method Statement and Risk Assessment.
* Operatives training records.
* Equipment information: You need to be sure that all the rigging equipment conforms to the requirements of LOLER 1998, including the nets, this means that every component used in the installation is uniquely identifiable in such a way that it can be easily associated with its respective documentation. All equipment is inspected at six monthly intervals and the results of that inspection are recorded, these records will be produced on completion of an installation.
* A handover certificate for completed zone.You will need a Net access tag similar to scaffold tags stating the installation date, load capacity per catenary wire bay in terms of persons and material and LOLER 1998 re-certification date.
If you want to know more about our tension netting design and installtion services then please go to:
http://www.webrsl.co.uk/content/web-net.php
Or contact:
Tension netting systems have been used over the last 30 years in an industrial context. The first tension netting systems were pretty basic involving fishing net and some basic rigging. Things have improved but there is still a great variation in the standard of tension netting system products, rigging and engineering design.
If you are considering utilising a tension netting system the first thing to consider is whether tension netting is a suitable underdeck access platform for the structure you are accessing and importantly for the work task you plan to execute from the tension netting.
There has been a school of thought for some time that tension netting is a work platform that can be used for all of the work tasks that say a hanging scaffold is used for – we disagree.
In our opinion, as designers and sellers of tension netting system, we would not recommend tension netting for: Heavy duty work tasks; Hot works; any system requiring full and proper encapsulation.
The key reasons behind this is that a tension netting system, no matter how well designed will deflect. The more men and materials on the system and the more it will deflect in often quite unexpected ways. This makes any work tasks involving delicate tool work, hot works or any other tools with a health and safety risk associated unsuitable for a tension netting system.
So that is the down side. The positives to tension netting is that it is extremely lightweight, fast to install and suitable for inspection or very lightweight work tasks. In these circumstances tension netting excels.
In our opinion there is no one perfect access solution, it is important to match the work task to the access solution. WEB offers a range of under deck access solutions and we take great care to specify what we believe will be the best solution for any project. Please feel free to call us up and we will be happy to advise you on what access system best suits your needs.
Please take a look at our tension netting information on our website:
We now have a WEB You Tube channel with videos of recent projects. The video below is of a recent contract at the Kyle of Tongue which was successfully executed 5 weeks ahead of schedule. This was due to the time savings offered by our access system compared to the timetable planned using hanging scaffold.
The WEB Deck offered a time and cost effective temporary work platform solution to the under deck of the road bridge over a river.
Take a look at our latest video. It shows how our innovative access solution has been successfully delivered on site at a loading jetty for over 2 years. Suspended scaffold can be slow and expensive to install. Our under deck access solution replaces suspended scaffold with a new suspended staging.
http://www.youtube.com/watch?v=Jvh13gkQBjk&context=C32f97a6ADOEgsToPDskIVCysk9juiDmMTqAz9pc_x
WEB Rigging is currently working towards an exciting project on the Gate Towers in Abu Dhabi. After the lift of the table top, all 200 metres of it – the WEB systems will be used to provide the under deck access.
Scaffold is without a doubt an excellent product which when applied to the correct set of circumstances provides a fast and cost effective solution. What we have done is to take a look at the circumstances where we see that scaffold does not provide a best fit access solution and design a better solution, the WEB Deck. If you are looking at a ground based access solution where you have no issue with access to the ground level, then scaffold fulfills its purpose. However, when you enter the work sites where you cannot use or obstruct the ground level then hanging scaffold is erected with a much higher time to install and therefore cost. This is one of the sets of circumstances that scaffold metaphorically falls down and where the WEB Deck provides a faster and therefore cheaper temporary work platform.
Scaffolding under bridges is a classic scenario where time and costs increase dramatically. The typical work scenarios include hanging scaffold under bridges because of water, roads, rail or rough ground underneath. In these circumstances to hang scaffold off the bridge is very time consuming compared to a ground based scaffold system.
Another scenario where hanging scaffold under a bridge hits problems is where the bridge is wide. A bridge requiring an under deck access platform which has more than 2 lanes, then the time and costs increase dramatically. Under these circumstances, there is no exponential increase in cost for the WEB deck because the width of the bridge does not alter the complexity and therefore cost of the install.
In order to illustrate this point take a look at the table below which outlines a bridge under deck are of 30m x 10m. The numbers are estimates and will vary from project to project, but they offer a good comparison of the products in this work area application:
| WEB BENEFITS | 30m x 10mwork area | Scaffold1.5 kN/m2 | WEB Deck1.5 kN/m2 |
|
•40% time savings min.
•30% cost savings min.
|
Total time (rig & de-rig) man days | 120 | 50 |
|
•8 x Lighter
|
Hung Weight (tonnes) | 42t | 5.1t |
|
•75% less volume
|
Storage volume (m3) | 125 | 32 |
|
•55% reduction in exposure to Work at Height
|
Total time (rig & de-rig) man days | 120 | 50 |
|
•87% less contact points
|
Contact Points & Droppers | 590 | 72 |
|
•Stronger
|
UDL Range kN/m2 | 0.75-2.5 | 0.5-5.0 |
|
•2 x FoS
|
Factor of Safety (FoS) | Typically 1.6:1 | 4:1 structural3:1 Deck |
