Hacker News Reader

Comment by IshKebab | Hacker News Reader

"You should study the manual before you use this potentially deadly system" is about the dumbest way to design a potentially deadly system ever.

Decades of experience has repeatedly taught that people are not perfect robots that always read manuals, and if you design your system under the assumption that they are then it is you that is at fault, not them.

There's a reason we have safety interlocks and dead man switches and seat belts and helmets and ... It's no use having a manual that says "do not open the microwave door while it is running".

View on HN

You might be surprised at how many machines work that way, though.

There's the classic aphorism about tools like lathes: "This machine has no brain, please use your own." But that's usually in an industrial setting with OSHA, mandated safety trainings, inspections, a culture of reporting unsafe practices without judgement, etc.

As CNC machines get cheaper and smaller, we are starting to see things like laser cutters sold to consumers with a pair of glasses and a manual rather than an enclosure. Hope you remember to lock the door if you have kids or pets...

It is a worrying trend which seems to be accelerating in the US due to crumbling and senescent regulatory institutions.

Those new consumer goods are a lawsuit away from fixing whatever dangerous characteristics they are shipping with today.

More like they are a lawsuit away from shutting down. It’s far easier to kill the product and then cry about how unfair lawsuits add no regulation are than to just fix the problems.

No, they are a mandatory binding arbitration away from keeping accountability at bay, with an NDA.

Lathes are a good example of exactly what I'm talking about! The manual might say "don't start the lathe with the chuck key still in place" but that doesn't stop people from doing it.

A much better solution is to add a physical safety interlock which prevents you from starting the lathe without removing the chuck key, which is exactly what some lathes do!

I agree the safety level of a lot of Chinese machines is very poor.

I mean, that's like saying if you design a plane under the assumption that the pilot will be trained then the plane manufacturer is at fault. There's definitely a level of expected responsibility on the user. If somebody starts a chainsaw grabbing the blade instead of the handle does that mean the chainsaw manufacturer should be at fault?

I'm pretty sure safety has a list of how to deal with safety based on practicality - the top of the list is to design the equipment so the safety risk isn't possible in the first place (e.g. design the device so touching it doesn't electrocute you), then various levels of mitigation (put a barrier around it, put clearly marked concrete and physical distance around it), then only if all that is horribly impractical comes the "solution" of training the user not to do the dangerous thing.

Also, aren't chainsaws nowadays designed so that if the user doesn't have two hands on the chainsaw grabbing the triggers, the chainsaw automatically cuts off? IIRC that's a thing.

Edit:there's the grip-safety ("safety throttle") for the trigger finger and there's the chain break for the forward hand, which will push forward and activate the brakes if the hand let's go or if recoil pulls the hand forward.

The user also needs training as there's still no way to guard the exposed blade when in use nor to keep it out of proximity of humans.

> You should study the manual before you use this potentially deadly system is about the dumbest way to design a potentially deadly system ever.

That’s exactly how the manual/pilot operating handbook and supplements for most airplane autopilots (and airplanes) read.

So should we start having drivers license requirements as hard as pilot license requirements? If not, then their manuals aren’t so comparable.

Maybe I wasn't clear - obviously sometimes you need to resort to training. But "they should have read the manual" doesn't excuse you from any attempt to make something safe and easy to use without reading the manual. That should always be done if possible.

Reply on news.ycombinator.com