We were asked by a client to design a support frame that could safely support cable containment weighing nearly 1.5tons and running 6 metres above ground.
We spoke to one of our design engineers to provide a deeper insight into this project.
“Typically, when a support frame is requested, we first look at the surrounding location and where best to fix back to, to ensure the services can be supported adequately.
Due to the required access through the doorway and stairs, we had to design a structure that could support these double layer runs of cable ladder running nearly six metres up in the air. The cable weight of over 1300kg needed a heavy-duty frame with high torsional strength and excellent rigidity, particularly as it was over 4.7 metres wide and 2.5 metres deep.
The next challenge to consider was the environment, with a frame of this height, wind loading had to be contemplated, even though it was close to the wall. To mitigate against the risk of bowing or excessive deflection we designed the frame with two sets of goal posts from Framo 160 and five supporting cross members of Framo 100; three running above the cable ladder and two running beneath.
To make sure the suspended cable ladder could be easily fitted to the frame, we suspended trapeze brackets at either end of the cross members.
Finally, we fixed the frame to the surrounding concrete slab with specified fixings to ensure adequate support.
Once on-site the modular frame could be easily installed.
Why did we design the support frame out of Framo?
There is no doubt that there is a growing desire within the sector for tested and compliant bracketry for supporting M&E services. The use of secondary modular steelwork and in particular, SIKLA Framo meant that we could provide quantifiable evidence to show that the designs were fit for purpose. From a sustainable angle, the use of pre-fabricated modular support frames meant the client saved on both embedded and operational carbon throughout the installation. From a practical point of view, secondary modular steel can be easily assembled on-site and adjusted, if required, without the need for hot works or cutting / drilling.
How important are anchors/fixings when supporting frames?
For all of our projects, anchors/fixings are specified following the guidance set out in BS 8539. When the design strength of a substrate is unknown and ETA-approved anchors are not requested we carry out an allowable load test on-site to determine suitable anchors/fixings. If anchors/fixings are discussed once the principal (tier 1) contractor has accepted a project then they can be suitably specified and installed correctly.