Ok, you have all been very patient while I have been struggling with the Hero so I am proud of you all. Here then is what you have all been waiting for……the juicy bits on the Opera House job.
By now you should have all read the story in the previous postings and there is absolutely no inkling of juicy bits in that lot. That was all written long before I graduated as a story teller. It was pretty dry stuff I must admit.
So let me correct that perception with the following.
You all saw in that story the difficulties that the designer of the robot had with traction on that sloping glass roof covered in soapy water. Well the same thing applied to us poor humans. Slippery wet soap covered glass canted at 15 degrees from horizontal made for a very precarious perch and this was long before Occupational Health and Safety came on the scene.
What did that mean? Simply that we all wore no safety harness. When I think back on that now I shudder actually but I am getting ahead of the story.
We were all given little chamois bootties to slip over our shoes which certainly provided a reasonable grip on the glass and did make us feel much safer. However it was the awe inspiring view that tended to overwhelm once you walked out onto that glass roof.
Surrounded by towering buildings, the glittering harbour view and dominated by the Sydney harbour Bridge it was indeed an overpowering experience. Especially to someone who spent much of his life locked in a dogbox working on microscopic components.
Anyway the day in question was one of the final inspection days where we had to demonstrate the finished robot under operational conditions.
What was not highlighted in the ETI articles was the cleaning brush roller was on a drop-arm which automatically cut off air to the forward drive, leaving only the reverse drive in action. This feature was included to allow the robot to drive right the edge of the glass roof at which point the brush dropped and stopped the robot until the reverse command was given; all very neat in theory.
Come the time to demonstrate this feature things did not quite go to plan. The driver may have approached the edge a little too quickly or something and when the drop arm fell off the edge there was a slight delay in cutting off the air and the robot ended up sitting right on the edge, teetering backwards and forwards, rocking as gently as a baby in the breeze.
The apprentice that was with us was a quick thinking lad and he immediately grabbed the air and water hoses and kinked them hard, shutting off all air and water to the robot. We all stood around patting him on the back saying well done lad but our hearts were still in our mouths because the robot was in such a precarious position.
Now I cannot remember the exact details of the debate that followed but it was decided that we would try to drive the robot back from the edge as called for in the plan and this called for the apprentice to release the hoses in order to restore power to the reverse drive.
The moment he did this the force of the air and water hitting the robot pushed it hard forward and thus the poor little thing jumped right over the edge which was some 50 meters or so above the walkway below.
That poor apprentice was still hanging onto the hoses at the time and he went flying forward and ended up sprawled on his stomach halfway down the roof but still hanging desperately onto those hoses for dear life. Luckily there was only about 15 meters of spare hose so when we made our way ever so carefully to the edge and looked over, there was the robot suspended by two quick disconnect hose fittings swinging gently in the breeze, 15 meters below us. It was a sight that I will never forget.
We had to haul the robot up hand over hand standing right on the edge of that roof. It really was a frightening experience. Still all ended well and we took the robot back to the factory for mods to the drop-arm switch.
The final test a week or so later cleared the robot for operation and we all let out a major sigh of relief. I had no desire to scamper around that roof any more than I had to.
Still it was all good clean fun ……… if you will pardon the pun.