Tension wires sound like a good option. If you could bring projector forward there are I-beam clamps for poles that may be better to hang directly below beam. Another option that maybe more rigid is a scaffold pole clamped between the beams and a pole clamp hanging projector on that. I had some projectors in rooms hung from scaffold poles clamped to I-beams. Not sure I'd go for short throw option though. I've encountered issues with short throw onto hanging screens because any screen sway in a draft or curl in the screen gives amplified distortion of image due to the steep throw angle so I'd prefer to use long throw projectors on pull down screens.
Thank you for all your feedback and solutions it is appreciated, tension wires and a clamp sound like the best option.
Feedback from the supplier was if the pole was shortened and the uni struts were reinforced this would solve the problem!
Question:how would this work when the keystone was adjusted? i adjusted the keystone and the keystone is limited,this option will not work as i don't want to sacrifice a quality image just so it will fit on the screen!
Thinking about it makes sense for the AV supplier/installer to use the correct installation materials/projector and measure up before hand as this will result in a better solution for US the customer as this will be hanging in the hall for years to come.
This has and is a learning curve for future projects, will definitely need to find some additional suppliers and add them to my contact list, the problem i have found over the 10 years working in schools is the ICT supplier will nearly always sub-contract the work out, what i need is an AV specialist and a company that can fully understand the schools need with regards to ICT server/computer installations and configurations (any recommendations please please please).