Over the years, I've come across several 'very unsafe' gas installations on boats - abraded pipes, loose unions, bottles bouncing about in their lockers, restrained only by their regulator piping..... The gas explosion on HMSTY 'Lord Trenchard' a few years ago brought that to mind, as that Nicholson 55 had just about every gas safety device and procedure that the Services could think up - and it still failed catastrophically!
I came across this PDF info brochure today, and think it may have relevance to some: http://www.outdoorbits.com/Brochures/St ... eel_A4.pdf