The story of the autoclave, or “Denga Wollof tutti rek”

By Martin Thomas and Dave Leopold.

On Monday we had a tour of the hospital and we came across two autoclaves, one working, one broken. We realised instantly the consequences of the second autoclave breaking down – theatre would stop running for example.

Close analysis of the 2nd machine showed that the door was buckled, which is a 20mm thick sheet of stainless steel, 600 x 700m with a steel frame. Staff reported there had been an explosion filling the room with steam. The reason it was buckled was because of a bolt failure securing the door shut, which may have been caused by anaerobic stress corrosion due to using two different metals: a ferrous carbon steal split pin through a stainless steel bolt.

We emailed Priorclave in the UK, the manufacturers of the autoclave. Their engineer called Terry Ashton emailed us back and was aware of the bent door. He felt that the door could be fixed.

So, we phone around to work out how we could flatten this door.

We soon had the door off and on the back of a truck. At this point Ismaila Chan, the head of the engineers at the Royal Victoria Teaching Hospital (RVTH), told us that the first autoclave had stopped working.

This now meant that there was no sterilisation in the hospital. After a little panic, we asked the engineers to take the covers off, which they did, but with the power still on and some disregard for their health and safety.

A safety microswitch on the door interlock had bent. It was an old switch, with loose bolts. The engineers removed it, bent it back and rebolted it. That autoclave was fixed and working fine. “Bhana trop!”

We drove the bent door around looking for a 60 tonne press to flatten it. In one workshop the owner was very helpful and would have done it, but only had a 50 tonne press.

The RVTH suggested that we spoke to Kevin Taylor, a Canadian engineer at the MRC. He suggested that we take the door to his lab and sent a photo of the door to Terry Ashton to discuss the problem. Kevin suggested that two guys with sledgehammers could probably bang it flat.

Kevin, however, had decided to retire an MRC autoclave and donate it, with manuals and service history, to the RVTH. The RVTH will now have two working autoclaves, and hopefully a third if we can all work together to get the bent door flattened!

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