On our maintenance trips to Tenerife one of the things we always have to check is the dome. Our system operates every night with good weather, and the dome rotates in the day to keep the solar panels pointing at the sun too.. all in all it has a pretty hard life.
Normally we check the battery on the dome to make sure we'll be able to open and close the shutter safely. We also check the wheels that the dome turns on.. more than once we have managed to destroy the wheel bearings. It makes the dome sound bad, and if the wheel were to completely fail the consequences would be a large amount of system down time at the least.
On this trip I've been greeted with a quite unexpected problem, for the first time in the ten year history of our dome the wire that opens and closes the shutter had started to fail. The nature and speed of the failure are quite shocking to me. In the June/July maintenance trip there was no sign of wear at all. On this trip we found that the wire had frayed and had just two of the component strands intact.
When you consider that this cable is the only thing standing between all of our hardware and the weather outside, the timing of our discovery was a bit close for comfort.
Luckily fixing the problem has not been to difficult. As ever we had to deal with a dome manufactured in the US, and parts from European suppliers. The new cable is marginally thicker, but not enough to cause a problem. The biggest difficulty of the repair was finding a crimp tool to attach the eyes at the ends of the cable. This was hampered by a national holiday out here, but to be honest I don't think that any hardware suppliers we have visited since have had the correct tool. In the end I improvised by modifying a part of bolt cutters. 15 minutes with a Dremel and file, and I'd managed to fashion a crimp tool for the job.
The problem was not a big one.. but as with much of the work we do here it was unexpected and the limited availability of parts and tools made it an interesting diversion and put our schedule a day behind.