If its only the windows to clean, would one man cleaning them and another just sorting out hoses and providing general supervision and guidance not suffice? Could they be harnessed together so that even if one fell in, the other would likely not go at exactly the same time?
Just spitballing.... 
for someone that askes companies to supply a rams before you give the work out, you seem to know little about them!
the idea of rams it to reduce the risks, so in other words for this one to reduce the risk of falling off the wall.
someone holding a hose for the other bloke to walk up there wont reduce the risk of that bloke falling off.
as for one person being harnessed together that means instead of one bloke being at risk there are now 2 people at risk so increasing the risk by 100%. the person wont be able to stop the other falling in he will just be pulled over the edge with him!
Some risks cannot be removed, the river will always be there. What I thought a RAMS is for is to inform of the risk and say how you intend to negate that risk. Some jobs will always be plain dangerous no matter how thorough the RAMS. Provided the RAMS is sound, you just need a man crazy enough to follow it.
Regarding increasing the risk by 100%, that's not true. Both men, if the job is thought through properly are not at equal risk. I weigh 80kgs and am a strong swimmer. One of the guys who works for me is about 110kgs and a tree surgeon. If I LEAPT in and swam away from him with all my might, there is STILL no way I would drag him in. The risk to him is minimal.
Potholing is dangerous. A RAMS is needed. The RAMS highlights how dangerous the exploration will be and what safety measures will be in place. But the very real danger of death still exists. You just need someone who is happy to work in spite of the risks.
In this instance, the risk cannot be removed. What can be done to negate the risk? Apart from some of the smart answers like 'helicoptering' etc. mine seems to be quite sound. Yes, there is a risk, so highlight it on the RAMS. It can be negated with my following suggestions:
It would not be wise to do this alone. Having a second man on hand would negate the risk.
Could PPE in this case be a life jacket? Yes. If the man doing the cleaning was anchored to a solid structure that would not move if he fell in, maybe not another person, that would negate the risk further.
So lets say he does fall in the river, he will float because his life jacket would keep him afloat. He will not float off down the river because he is anchored to a solid structure. His mate can then call for help, haul him in, or do both.
I was spitballing with my first suggestion. This time I have given it a little more thought. I would happily write a RAMS for this job. I would be happy including the above info and word it accordingly. Because it is not a standard job, a standard RAMS for window cleaning will not suffice. You need to think and work a little differently with perhaps not even an increased risk to health or safety, just a different type.
The very beginning of your post says "for someone that askes companies to supply a rams before you give the work out, you seem to know little about them!"
That statement is untrue. I am not sure how you can reach such a conclusion based upon an idea, i did say i was spitballng. I know an awful lot about RAMS and the reason I ask for RAMS is that a lot of the solar jobs are non-standard. I need to know who's suitable and who isn't. Some can come up with non-standard RAMS and some can't.
An exercise like this thread gives me a good idea of what's what too.
