Propeller Accident Statistics

[9D280]

Observer.

Your response is, like a lot of both sides of this thread somewhat sensationalised.

What I am reading here is a lot of people who spend a lot of hours in fast, open boats and who have practical experiences (most of whom including myself have admitted forgetting the KC at some point in their boating history) pointing out some practical & real life concerns with the "headlines".

Now, your (I assume you are part of the PGIC lobby) bubble chart has some good stuff in there. I also agree tech has improved immesurably in the last 40 years (I have fitted KCs to at least 3 engines from the late 70s), but look at car safety. People still don't wear seatbelts, people still use their phones, sitting in there on the hard shoulder of the motorway when broken down etc etc. I have also noticed that as cars get safer, driving becaomes worse - presumably the illusion of this "safety cocoon" that the car has become makes people think they can get away with more. Bottom line is unless they hit a 200 ton concrete block exactly perpendicularly and at exacly 30mph or an EC approved deformable barrier at exactly 40% offset or whatever the tests are - your crash survival is down to luck.

And your bubble chart page has, I believe made a lot of us on here think about how we can improve our own set-ups.

One to add to your list: The KC is essentially a "short to kill". thre worst case fault is that the wire breaks, so it never shorts. I have experienced a connector vibrating loose so although it worked fine when I tested it as I left the marina, it didn't stop half an hour later when I pulled the cord at my destination. (more "real time" testing) So, hows about something that detects the ignition voltage (or a tracer voltage, probably need to be HF AC to allow something to detect it without shorting the ignition - HF can be de- coupled with capacators) that squeals when the circuit fails or keeps a lamp (or LED-less likely to fail) lit when active?


The biggest problem with all these new fangled ideas is (and even assuming they work for everyone) that if someone gets it in their head that the boat will look after them, they are instantly going to be less careful & safety minded themselves. It's human nature.


- Ever nearly run into the back of a car that you didn't see in heavy rain because the auto lighting in said car reckoned it was bright enough not to need them switched on and the driver had long forgotten where the light switch even is on the dash?


I would suggest, as have many on here, that education & awareness will go a very long way. Tech just for tech's sake can be dangerous. Technical Ideas like this have to work universally and not mean that people brought up with them become unsafe when driving old boats.

Let's go back to cars for a moment:

When did you learn to drive? Did all cars have Stability control? ABS? Airbags? I learned in an Austin A40. Brakes were all round drums, and no vacuum assist. I still go down the gears when I stop because when I learned the engine halved the braking distance. I also drive to assume my ABS won't kick in. I think I've triggered it twice on ice just to chheck it actually worked in nearly 250,000 miles that i;vce owned a car with the tech on board. I bet any "kid" who drives an A40 / Mk 3 Escort or other random old car today would a) Put it straight into a skid during an E-stop and b) Pile into the car in front at the first set of lights.

Need I say more?

[Sixy_the_red]

It has been a legal requirement to install boom over height warning systems on lorry loaders (*cough* HIABS *cough*) since 1998. The system is designed to warn the driver if he attempts to move off with the arm of the crane raised above the maximum vehicle height marked in the cab.

Has this stopped lorry loaders from hitting bridges? What do you think?

Technology and legislation in the industry is becoming more and more complex all the time. The aim is to stop the idiots from having accidents, but in reality all that happens is the skilled operators find their job more and more difficult. Make life difficult and people WILL try to by-pass the systems.

The trouble is, and the problem all engineers / technical people face is the 'Blue Sky Thinking' bregade who demand that SOMETHINGMUSTBEDONE to solve a non-problem without either a full understanding of the problem or any concept of the consequences of the 'solution'.

Now, I've been following the whole killcord, safety, training debate quite closely (in fact I started regularly using RIBNet again because of it) and I have only seen one or two even vaguely workable / practical suggestions. ALL of which have been ways of improving the current system by helping to remind the helm to attach the cord, not by making any fundemental changes to the system itself.

I have also seen a large number of quite rediculous 'blue sky' ideas that simply will not work reliably in the extremely harch marine enviroment. These ideas have been (constructively) shot down and rightly so.

Observer - you seem to be falling squarely into the 'Blue Sky Thinking' bregade. I don't see many people here being complacent about the problem, rather being realistic about the way forward. 'Modern' technology is not always - if ever - the best solution to what, in this case, really is a very simple problem. I don't know about you, but I'd rather trust my safety to a big clunky electrical switch than some fancy computer that thinks it knows better than me, particularly in an enviromnent where accidental activation is just as dangerous if not more so than the hazard the system is trying to avoid.

[PGIC]

Originally Posted by Cookee

Detect screams? How much have you really thought this through?

We have thought it through quite a bit, thank you.

One of our roles is to scout emerging technologies with potential application to propeller safety issues. We draw attention to those technologies to encourage further development and applications by companies and individuals working on propeller safety devices.

In July 2007 we published some information on how screams might be used to detect people behind the transom when the engine is about to be or has just been started. While not related to kill cord preventable accidents, starting an outboard or stern drive with people near the stern is a common mode of propeller injury. At that same time we noted gunshot detection was being used in some cities (detect a shot went off and triangulate location) plus we published a list of five references applicable to scream detection.

Much earlier we had published information on Cognitive Sensors and Data Fusion. The use of several sensors to make somewhat fuzzy decisions. Sort of like how you decide who to vote for in a political election. The use of multiple sensors improves accuracy and reduces false positives.

I firmly believe that scream detection is a good candidate for being one of those variables being detected by those working in this field. Not only can panic screams be specifically detected, their location can be as well.

In addition to transom startup propeller accidents, scream detection also has application to man overboard situations (screams when falls out), and to unmanned boats circling at people in the water (screaming for help), just like kill cords do.

For those who think scream detection is silly, we suggest you see some of the work done in this field:

http://scholar.google.com/scholar?hl...%2C37&as_sdtp=

Much of that work has been done since we identified scream detection as an emerging technology with potential application to propeller safety devices. The work was obviously not done due to our July 2007 note, but those who started thinging about applying the technology to propeller safety devices back then now have much more material to work with and would have been well ahead of the curve.

Scream detection combined with sensor fusion is NOT meant to be a better method than kill cords. It is being suggested as a better method for those who do not use kill cords and probably never will.

Here in the U.S. the Coast Guard has spent tens of millions of dollars over the last many years promoting the wearing of life jackets, yet adult life jacket wear rates in open motor boats are still hovering near 5 percent. We have seen no kill cord use rate surveys (beyond some calculations we published ourselves) but suspect use rates are quite low here. IF a low cost, reliable technology based system could be developed to help the non kill cord users and provide absolutely no downside for the existing kill cord users (such as it is an optional aftermarket device and they don't have to add it if they don't want to), I think it is at least worthy of mentioning the concept.

gary

[9D280]

Originally Posted by PGIC

In July 2007 we published some information on how screams might be used to detect people behind the transom when the engine is about to be or has just been started. .

Dare I suggest a possibly more practical alternative?
Fishfinding tech has been around for years - if you can find your dinner at not much more than a foot long at 200' depth surely it's an easy step to motion detect a big lump of human in the water a couple of yards behind the boat? - No new tech needed, all you need to do is fit a couple of sensors on the transom either side of the outboard (or build them into the leg on new outboards) then write the software that can tell the difference between a body (who may already be unconcious so not moving) and quay wall or bobbing keel of the boat alongside you & job done.

Originally Posted by PGIC

also has application to man overboard situations (screams when falls out), and to unmanned boats circling at people in the water (screaming for help), just like kill cords do.

Only screaming for help if they are conscious or not coughing & choking with the lung full of brine they ingested by reflex when they hit the cold water....


On the plus side, if the system was retro- fittable it could act as a "double deadman" and if a "stop relay" was incorporated in the hardware it could be fitted to older boats in parallel with the KC switch. (but does that again come back to calibration (detection / location) issues if it's sold on when the boat is pulled out of service)




Hows about an IR motion detector on the A- frame No "moving" heat detected in the "column" where the driver should be (to prevent sun on the bow giving a false "present" signal ) - engine cuts. (again probably needs a throttle or carefully timed input as I can think of a few occasions where I lean over to get a rope round a cleat before I switch off, but want the engfine running in case I miss & the current / wind puts me somewhere Idonlt want to be..... Granted will only work if you got somewhere to mount the sensor(s) & comments about salt deposits above still stand.

For tiller control, throttle hold detection could be a possibility, but again the mooring scenario could be a pain. IR presence detectors for "arms length" operator might work, but would be U/S if someone got thrown as the engine swung & found themselves in the "zone". Combining the two might prrovide a workable solution, although how you detect someone on the tiller could prove interesting, as there are an infinite combiantion of dry/ wet hands in numerous flavours of glove...... Do people grip it tight enough to use a piezostrain gauge?


Food for thought.

[Poly]

Well you have all brought some amusement to my day. However can I suggest before anyone gets into an argument over the prospects of hearing a scream over an outboard, or gets offended that the whole world doesn't agree with them that they familiarise themselves with the RIBnet posting guidelines - especially this bit:

Originally Posted by John Kennett

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Make sure that what you post is correct
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Originally Posted by PGIC

IF a low cost, reliable technology based system could be developed to help the non kill cord users and provide absolutely no downside for the existing kill cord users (such as it is an optional aftermarket device and they don't have to add it if they don't want to), I think it is at least worthy of mentioning the concept.

The only people who fit after market safety devices are the safety conscious. Safety conscious people will use the existing, generally very effective, solution. Those who rely on luck or devine intervention to prevent themselves getting hurt are unlikely to see the need for an add on. I assume market positioning is not one of the consultancy services that Poisson Enterprises offers its clients?

[PGIC]

Originally Posted by 9D280

Dare I suggest a possibly more practical alternative?
Fishfinding tech has been around for years - ...

Only screaming for help if they are conscious or not coughing & choking ...

Hows about an IR motion detector on the A- frame No "moving" heat detected in the "column" where the driver should be ....

For tiller control, throttle hold detection could be a possibility....

Thank you for suggesting some alternatives, however:

We noted on our site back in July 2007 that Furno had just released a new digital fish finder with clearer detection in shallow and deep water, plus it specifically suppresses surface clutter caused by the propeller and once again at that time we encouraged those working on propeller safety devices to consider fish finder technologies.

I have seen countless reports of people at the stern being struck by props at startup that mention the person screaming as the engine started.

Our site long ago noted the Mercury patent by Dick Snyder (US Patent 6,450,845) issued in 2002 for an infrared device of the nature you mentioned.

We suggested the tiller deadman back in 2008.

There are many such approaches, some of which might best be utilized in combination with each other as we mentioned earlier.

gary

[PGIC]

Originally Posted by Poly

The only people who fit after market safety devices are the safety conscious. Safety conscious people will use the existing, generally very effective, solution.

I suggest safety conscious people or organizations not able to positively control the boat operator's actions might opt for an alternative, such as:

1. Parents concerned their teenage kids might not always hookup the kill cord when they take the boat out.

2. Boat Rental / Livery operations concerned their renters will end up getting themselves chopped up because they failed to hookup the kill cord.

3. Boaters living in an area of a recent high profile kill cord accident that are concerned about controlling their own actions (just as many people in this forum mentioned, they know they don't always hookup themselves.)

gary

[captnjack]

Sorry to see you're getting so much pushback here PGIC. While some of your ideas seem a bit far fetched, what it really comes down to is some sort of government mandate.

Industry (and established users) almost never want to pay even a little bit more for a new safety technology. If you look at the history of automotive safety features manufacturers and some consumers "poo pooed" and delayed/stalled the incorporation of almost every one. Safety glass, seat belts, air bags, ABS brakes, etc etc.

They are always derided as: too expensive, unreliable, unproven, unnecessary or taking away control from the driver/user.

So sadly, I suspect you have an on-going battle ahead of you. Keep up the good fight.

R

[PGIC]

Originally Posted by captnjack

Sorry to see you're getting so much pushback here PGIC.

Industry (and established users) almost never want ...They are always derided as: too expensive, unreliable, unproven, unnecessary or taking away control from the driver/user.

So sadly, I suspect you have an on-going battle ahead of you. Keep up the good fight.

I am long accustomed to pushback, but thanks for the encouragement.

gary

[captnjack]

Personally I liked the RFID proximity sensor idea. Something which could be clipped in a pocket and the engine shuts off if its beyond range. With a user adjustable range so I could go up to the bow and anchor etc while the engine is idling or being controlled by a crewmate while I anchor.

These dataloggers are waterproof to 500ft and are a totally functional size. ReefNet Inc. | Sensus Ultra The "other half" of the switch would be under the console.

While this would not avoid startup strikes, I find myself removing the kill cord for 2 reasons: anchoring and helping retrieve divers from the water. I almost always shut the engine down for retrieving divers. But I might restart and move the boat "a little" to go get another one etc. Its these moments when I am unlikely to reattach the kill cord. For anchoring I don't want to shut down until I'm hooked, but I end up walking around with the engine one - even if just idling/ in neutral it still creeps me out.

My price point would be about $300 US. If someone would only make it.

Yes the RFID could be "bypassed" by just putting it on the keychain hanging there. But if I spend money for this improved cordless kill switch I am going to use it.

[PGIC]

Originally Posted by captnjack

Personally I liked the RFID proximity sensor idea. Something which could be clipped in a pocket and the engine shuts off if its beyond range.

My price point would be about $300 US. If someone would only make it.

Have you seen Autotether? They are widely available. Price point about $200.

How it Works - autotether.com

It physically yanks out the kill cord.

gary

[Poly]

Originally Posted by PGIC

I suggest safety conscious people or organizations not able to positively control the boat operator's actions might opt for an alternative, such as:

1. Parents concerned their teenage kids might not always hookup the kill cord when they take the boat out.

2. Boat Rental / Livery operations concerned their renters will end up getting themselves chopped up because they failed to hookup the kill cord.

well if they don't want to actually solve the problem, but introduce false confidence then perhaps. Personally I would rather that both focussed on making sure their users were competent and responsible rather than hoping that technology will solve the issue. If you don't trust the user - don't give them the keys.

3. Boaters living in an area of a recent high profile kill cord accident that are concerned about controlling their own actions (just as many people in this forum mentioned, they know they don't always hookup themselves.)

in reality a tiny number would actually spend real money (ie. hundreds of pounds) to fix the problem. There is a good suggestion in one of the other threads about switching from keeping the console end attached 99% of the time and unclipping form people to keeping the people end attached and disconnecting the console end every time your step away. This costs nothing (or perhaps £10 so all the crew have their own kill cord). I'll guess 9/10 people here still go for the leave it dangling approach.

Originally Posted by captnjack

While this would not avoid startup strikes, ... ... For anchoring I don't want to shut down until I'm hooked, but I end up walking around with the engine one - even if just idling/ in neutral it still creeps me out.

My price point would be about $300 US. If someone would only make it.

wireless kill cords are available, although not at that price. As you say though it only stops one type of accident (MoB prop strike) not divers, swimmers etc. I'd be looking to see if you can change your method of operation to avoid leaving the controls in the situations you describe - I know it seems impossible - but I've seen some very capable skippers on this forum manage some very large ribs - all from the helm seat with good planning and preparation.

[captnjack]

Originally Posted by PGIC

Have you seen Autotether? They are widely available. Price point about $200.

How it Works - autotether.com

It physically yanks out the kill cord.

gary

Looks good except for 2 parts:
"Do not shield or cover the Fob with wet clothing, your arm, leg or another person or pets body, which may cause the Fob to act as if underwater, resulting in sudden accidental stopping of the vessel."

and its only waterproof to 3ft...

I need the sensor to go in a drysuit pocket, which will be wet, if not before the first dive then for sure afterwards. Its also highly likely that I will forget its in my pocket at some point and it'll actually go for a dive.

Would be much more useful for me if the transmitter was on the boat side, and the sensor used passive RIFD technology which can easily be made waterproof to hundreds of meters and works (at close ranges) through water, wet fabrics, or tissues.

[Leapy]

Originally Posted by captnjack

Looks good except for ...

... Takes me back a few posts ...

"... and when a proven, reliable, stable, durable and practical improvement comes along I will embrace it totally, as I'm sure will the vast majority of folks on this forum"

[Nos4r2]

Originally Posted by Leapy

... Takes me back a few posts ...

"... and when a proven, reliable, stable, durable and practical improvement comes along I will embrace it totally, as I'm sure will the vast majority of folks on this forum"

Seconded.

So far all I've heard is babble.

[Observer]

As I said, the numerous naysayers on here, including particularly the two whose post precede this, are a disgrace. My opinion, validly expressed. Is it going to be censored?

[kerny]

[jambo]

Originally Posted by kerny

Getting tired and bored there old timer!! Might I add like most of us !!!!!!!!!!!!!!!!!!!!!!!

Sent from my iPhone using Rib.net

[willk]

Originally Posted by Observer

As I said, the numerous naysayers on here........, are a disgrace. My opinion, validly expressed. Is it going to be censored?

I have made my thoughts on this type of comment quite clear. Poly has given similar warning.

You are circling the plughole. Don't think of it as censorship, think of it as the Naughty Corner...

[paddlers]

Have to agree with you Willk , I can enjoy the debate but abrasiveness & occasional rudeness do nothing to further anyones cause !!
I enjoy the sarcasm that sometimes occurs and it's a great site for anyone interested in all things boaty but I'm pleased when the powers that be step in to douse things down.