The crematorium in our last village held annual open days, where you could have a guided tour and see how it was done (obviously no-one was being cremated while the tour was on!)

There, the coffin was slid into the cremator on some rollers and the gas flames came from underneath. I imagine if the body was uncontained, it might not slide in so easily.

But one could I suppose have a cardboard coffin to hand and decant the body into that, saving the 'nice' coffin for another customer.

When the curtains closed, we saw that the cremator was down on another level and the coffin lowered by a hydraulic platform into that department where the workers received it.

The remains were ground up in a machine called a cremulator after any metal joint replacements and teeth fillings were removed. The metal was sold by the crematorium managers.

The crematorium chimney had effective filters inside, to comply with air pollution laws.

I found it fascinating to see all this and have it explained.