ebee said:

So, is there a sort of "one shot adaptor" that could be plugged in to the socket and the machine plugged into it. switch washer to on then nothing happens till a "one shot" button is pressed and it will de-latch.

Washing machines usually require a complex sequence of buttons after closing the door, before they will start. The door 'interlock' then prevents the door being opened until the cycle is complete (even if power goes off).

However, tumble dryers are not the same. You can open the door part way through a cycle (because the drum rotates much more slowly it stops almost immediately the door opens), and then you used to be able to shut the door and it would recommence automatically. HOWEVER, a number of years ago, the feature you describe is built into tumble dryers now, so you have to push a button after closing the door, to re-start the machine - there's an electronic latch that keeps the power on if both the door is closed and the button is pressed, releasing when the door is opened.

However, neither of these mechanisms would be effective, if an adult or older child didn't notice a child (or a cat) had climbed into the machine and fallen asleep. But then it's the adult or older child who has caused the machine to start with the child (or cat) inside.

The recommendation therefore would be to keep the child away from the machines when they are unsupervised.

I think rather difficult to climb in and then start a washing machine, but I can imagine one rather small child climbing in and another one pressing go. I have never heard of a tragedy arising in this way, but in the days when fridge doors had handles such as are found only in cold stores nowadays, it was not unheard of for children to climb into an old one, pull the door to, and then suffocate.

The sad thing is that children don't necessarily understand risk as yesterday's sad events have demonstrated.

TUmble dryers are, as I said, a little different. Accidents have been known with machines to older standards, for example:

cafemom.com/.../299262-as_tragic_as_this_story_is_its_not_the_first_time_an_accident_of_this_kind_has_happened

https://www.theguardian.com/uk/2010/aug/04/mother-arrested-tumble-dryer-death

BUT ... have a butchers at these. Not generally the kids doing stuff we need to worry about w.r.t. child safety (there have also been cases of, well I use the term loosely, people, tumble-drying pets to death (as well as microwaving them too):

https://www.scotsman.com/news/crime/monstrous-scottish-thug-who-put-baby-tumble-dryer-jailed-seven-years-1408189

https://www.thesun.co.uk/news/8224371/evil-dad-put-little-boy-in-tumble-dryer-and-turned-it-on-as-punishment/

https://www.mirror.co.uk/news/us-news/woman-accused-bundling-boy-tumble-26698136

https://www.independent.co.uk/news/world/americas/child-daycare-shutdown-michigan-b1959781.html

I think overall, it's probably worrying that (at least from press reports) it seems wilful harm with these machines is more of a risk than 'accidents'

More discussion here: www.whitegoodshelp.co.uk/.../

A bit more info. I spoke to the lady today. It`s a dryer not a washing machine. Apparently the two year old climbs in and pulls the door shut easy peasy. should another child then start the dryer it could be dangerous . The dryer is "a couple of years old" and the lady swears she always keeps it unplugged and the children can not reach the socket on the wall. My worry is the unplugging the dryer only needs forgetting once is a potential worry. Kids need supervising 200% of the time is never enough for toddlers, ask any parent.

My thinking is to build a socket outlet one shot switch might be a safer option in this instance

There might be a smart socket you could replace the one the dryer is plugged into with. So that it is solely controlled by a phone app, or even alexa with suitable parental controls built-in.

Thanks Olympus, I had thought about that but it might be left on or off so defeating the more simplistic approach. I do take your point though, modern tech can be fantastic and I`m sure the one shot (timed interval only) could be considered but for varying times, even by only a few mins, then the press a button to start then de-latch once a cycle completes would seem to accommodate a wide variety of timings on a wash or dry program, I`m still thinking that current draw monitoring rather similar to the "is the stat now satisfied?" approach might be an answer. a socket outlet controlled by say a 16A contacts relay and a little current sensing circuit might be quite strraightforward in a plastic box . |Sort of MAPJ1 or Big Clive kind of idea

ebee said:

My thinking is to build a socket outlet one shot switch might be a safer option in this instance

I'm not sure how such a device would work for a dryer, especially one with a mechanical reversing timer - because every few minutes, the machine stops to reverse, and if the heater is off (thermostat open), there will be zero current. Therefore, if the one-shot is looking for zero current, it might just activate when the machine stops to reverse.

Yes indeed it might need a slight run on delay for a few seconds say a cap or two to hold the relay . Starting to get more complicated now though innit? 

I was wondering about a bog-standard no volt switch with twist the red button, press the green one; but I think that it may suffer from the same disadvantage as a one-shot switch. What is there to stop a reasonably bright, but mischievous wee boy (i.e. a normal one ;-) ) from activating it?

I know a retired police officer who found a missing child dead in a washing machine, he said it was the worst experience in his entire career.