paulears Posted November 20, 2015 Share Posted November 20, 2015 I note that many aerial installers now routinely ask for permission to drill the wall to put in an anchor - which seems a rather sensible approach. As for the people - when I was teaching in college, early on we did a short test on a very tall A-frame, to help people set a limit. Some people could not go up a single step, others would ascend rapidly and touch the ceiling at about 7m. Those ones worried me. The ones who could not do it at all, I encouraged and got them comfy at maybe three or four steps - where they could work and be useful, but know that this was their own personal limit. The safest ones were the ones who were slow at first, and took it steadily. The quick, one handed ones were rarely much use - bravado and over-confidence are killers! ps I will edit the title - driving me mad! Link to comment Share on other sites More sharing options...
Jivemaster Posted November 20, 2015 Share Posted November 20, 2015 Footing a ladder. A ladder leaning against a "wall" unfixed, will tend to slip down at the top and out from the wall at the bottom as the climber ascents and the downward force on the bottom reduces so there is too little friction on to the floor to stop the slide. If someone stands on the bottom rung, there is down force at the bottom and friction (F=uR) increases with with the applied load. Obviously with an A-frame ladder the friction is replaced by force in the tie bar or straps. Link to comment Share on other sites More sharing options...
Simon Lewis Posted November 20, 2015 Share Posted November 20, 2015 What, the one from post #2? :) Doh...! :-) Link to comment Share on other sites More sharing options...
BenEdwards Posted November 21, 2015 Author Share Posted November 21, 2015 Thanks, lots of very good stuff. The bit about not footing Zarge, which is what we have is very interesting. Where I am, in a small volunteer run venue, its difficult enough to have one person on the desk and one up a ladder, let alone 3 people involved. I always tend to get someone to foot the Zarge, did not realise it did not make it safer, always thought you were meant to. It does seem to stop it wabbeling but guess this is mainly psychological in terms of feeling safe. if it really is a scientific fact that it does not help then that great. We have a multi stage (not combination ladder) we use FOH that is leant on the bar. Wandering if this should be footed to stop bottom slipping? I do however always make sure someone is in ear shot, and preferably in the auditorium so if I do get in trouble there is someone around. Apart from footing and making sure landers are put up correctly, and not over stretching (i.e. 3 points of contact) what other softy things should be done/taken into consideration? Ben Link to comment Share on other sites More sharing options...
gyro_gearloose Posted November 21, 2015 Share Posted November 21, 2015 Theres an easy way to ensure you never need to work at height on your lamps: replace them all with moving lights! As long as you can winch them down to the floor to change lamps or carry out maintenance you'll hardly ever need to use a ladder again. Or you could do what the TV and film studios have been doing for years and use pole-operated lights which can be focussed from the floor. Studios solved the problem of focussing lights when theres set in the way years ago, so I don't know why that technology never seemed to make its way into theatres. Of course both of those solutions are expensive, but they do make the often overlooked point that when planning working at height one should consider wether there are things that can be done to eliminate the need to work at height in the first place. Link to comment Share on other sites More sharing options...
Jivemaster Posted November 21, 2015 Share Posted November 21, 2015 There were BBC studios with lanterns on short trapezes one lantern per trapeze, this made lamp changes an easy floor level job, BUT the massive number of winches needed added to costs and testing and maintenance issues. Link to comment Share on other sites More sharing options...
paulears Posted November 22, 2015 Share Posted November 22, 2015 Going back to the first post - the idea of climbing an ordinary theatre style Zarges or A-frame with a harness would be out for me. Mainly because the only thing you could clip onto would be the lighting bar or other support, and the wearing a harness could make the job more risky. Can't see any real issue with clipping the top of the ladder to something solid though? I've never found it difficult up a zarges, but many people do not like the feeling you get when it flexes, and you can see the ground underneath you - so for these people, maybe they should just not try to go up them? Link to comment Share on other sites More sharing options...
Dave m Posted November 22, 2015 Share Posted November 22, 2015 I suppose if I was leaning a ladder up against a fixed bar then maybe a hook sytem akin to a roofing ladder might be able to prevent it slipping , but a big trapeze bar would swing about too much and a ladder footer would be safer. All our bars are either fixed or on a big truss.We have a tension wire grid ( obv the safest option) plus a big truss based rig split into two 7.5 m squares in another space.The truss needs to be focuses off a scope or A frame.We also have a studio with pantographs on roller bars. The pantographs runs east west on bars and those bars run north south on other bars. In theory you can get a hanging fixture anywhere. However it's like a game of Tetris if you need to add one fixture. They also cost about £500 a pantograph Link to comment Share on other sites More sharing options...
itiba Posted November 22, 2015 Share Posted November 22, 2015 How not to do it (and yes he is holding a large chunk of metal!) : http://s2.postimg.org/iy35b57ex/IMG_20140619_103224_hdr.jpg Link to comment Share on other sites More sharing options...
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