Winching - Cable danger.

[W.J. \(Bill\) Dean \(U.K.\).]

In discussions about winch design and construction, I think not enough
attention has been given to protecting the driver from the cable.

This is a report about one accident (B.G.A. 1991/20):

"At the top of a normal winch launch the weak link failed and a fast moving
"snake" of cable fell onto the winch driver's cab. It found its way
through a narrow aperture in the wire mesh guard and hit the driver about
the head, nose, jaw and teeth. Fortunately he was only marked and not
badly cut. The club proposes to modify the guard."

I know of another case where a "snake" of cable escaped from the drum, found
its way out of the drum cover, broke a window in the winch cab and attacked
the driver. It then disappeared back onto the drum leaving him to work out
what had happened. The driver was uninjured with torn clothing, he has not
driven the winch since. The drum cover has been improved.

In a third case the wire broke, then whipped back behind the winch and
attacked the winch driver's car parked behind the winch (with the front of
the car towards the winch). It trashed the rear of the car and then wound
back round and broke one of the front door windows which was up. I saw the
car afterwards, I would not like to have been sitting in it when this
happened, especially if it was a warm day and the window was down! This
particular winch driver was very experienced at winching.

All these incidents happened so quickly that there would have been no chance
to take cover.

These dangers are much greater than most people realise. They do not
happen very often, but are you prepared to take the risk?

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

[Bill Daniels]

"W.J. (Bill) Dean (U.K.)." > wrote in message
...
> In discussions about winch design and construction, I think not enough
> attention has been given to protecting the driver from the cable.
>
> This is a report about one accident (B.G.A. 1991/20):
>
> "At the top of a normal winch launch the weak link failed and a fast
moving
> "snake" of cable fell onto the winch driver's cab. It found its way
> through a narrow aperture in the wire mesh guard and hit the driver about
> the head, nose, jaw and teeth. Fortunately he was only marked and not
> badly cut. The club proposes to modify the guard."
>
> I know of another case where a "snake" of cable escaped from the drum,
found
> its way out of the drum cover, broke a window in the winch cab and
attacked
> the driver. It then disappeared back onto the drum leaving him to work
out
> what had happened. The driver was uninjured with torn clothing, he has
not
> driven the winch since. The drum cover has been improved.
>
> In a third case the wire broke, then whipped back behind the winch and
> attacked the winch driver's car parked behind the winch (with the front of
> the car towards the winch). It trashed the rear of the car and then
wound
> back round and broke one of the front door windows which was up. I saw
the
> car afterwards, I would not like to have been sitting in it when this
> happened, especially if it was a warm day and the window was down! This
> particular winch driver was very experienced at winching.
>
> All these incidents happened so quickly that there would have been no
chance
> to take cover.
>
> These dangers are much greater than most people realise. They do not
> happen very often, but are you prepared to take the risk?
>
> W.J. (Bill) Dean (U.K.).
> Remove "ic" to reply.
>
>
Bill, excellent point!

I have always considered the winch drivers job to be more dangerous than the
glider pilots. I tell people that each time I reach for the throttle, I
think about the 300 pounds of steel wire that is about to come straight at
me doing 70 MPH.

Steel wire mesh or screen is totally inadequate to protect the driver. The
winch cab windows should be 3/4" polycarbonate (Lexan) which, I'm told, will
stop a 9mm bullet fired point blank. Yes, Lexan will get scratched
eventually but it's not that expensive to replace. The rest of the cab
should be at least .125 inch steel sheet.

Spectra will reduce the danger somewhat but the rest of the hardware will
still be there and present the same dangers.

I would prefer a winch cab that is armored, weather tight and air
conditioned.

Bill Daniels

[JS]

> Bill, excellent point!
>
> I have always considered the winch drivers job to be more dangerous than
the
> glider pilots. I tell people that each time I reach for the throttle, I
> think about the 300 pounds of steel wire that is about to come straight at
> me doing 70 MPH.
>
> Steel wire mesh or screen is totally inadequate to protect the driver.
The
> winch cab windows should be 3/4" polycarbonate (Lexan) which, I'm told,
will
> stop a 9mm bullet fired point blank. Yes, Lexan will get scratched
> eventually but it's not that expensive to replace. The rest of the cab
> should be at least .125 inch steel sheet.
>
> Spectra will reduce the danger somewhat but the rest of the hardware will
> still be there and present the same dangers.
>
> I would prefer a winch cab that is armored, weather tight and air
> conditioned.
>
> Bill Daniels
>

What about chanching the rotation direction of the cable reels, would it
make the lose cable end hitting the ground instead of drivers cabin?

js

[F.L. Whiteley]

"W.J. (Bill) Dean (U.K.)." > wrote in message
...
> In discussions about winch design and construction, I think not enough
> attention has been given to protecting the driver from the cable.
>
> This is a report about one accident (B.G.A. 1991/20):
>
> "At the top of a normal winch launch the weak link failed and a fast
moving
> "snake" of cable fell onto the winch driver's cab. It found its way
> through a narrow aperture in the wire mesh guard and hit the driver about
> the head, nose, jaw and teeth. Fortunately he was only marked and not
> badly cut. The club proposes to modify the guard."
>
> I know of another case where a "snake" of cable escaped from the drum,
found
> its way out of the drum cover, broke a window in the winch cab and
attacked
> the driver. It then disappeared back onto the drum leaving him to work
out
> what had happened. The driver was uninjured with torn clothing, he has
not
> driven the winch since. The drum cover has been improved.
>
> In a third case the wire broke, then whipped back behind the winch and
> attacked the winch driver's car parked behind the winch (with the front of
> the car towards the winch). It trashed the rear of the car and then
wound
> back round and broke one of the front door windows which was up. I saw
the
> car afterwards, I would not like to have been sitting in it when this
> happened, especially if it was a warm day and the window was down! This
> particular winch driver was very experienced at winching.
>
> All these incidents happened so quickly that there would have been no
chance
> to take cover.
>
> These dangers are much greater than most people realise. They do not
> happen very often, but are you prepared to take the risk?
>
> W.J. (Bill) Dean (U.K.).
> Remove "ic" to reply.
>
>
A similar incident at Enstone circa 1993. Wire looped and came up through
the floor panel. Shattered ends whipped the driver's shins. Still carries
some the embedded shards. The floor panel was not secured. Had it been,
things would have been fine.

Frank Whiteley

[W.J. \(Bill\) Dean \(U.K.\).]

I don't think the direction of rotation of the cable drums would make any
difference. The damage is done by the energy in the moving wire. It was
not the loose end which went astray, it was a bight in the cable.

With the Skylaunch winch the wire winds onto the bottom of the drum, with
the Tost and many others onto the top. The two cases I knew about
personally were with the Skylaunch, I do not know what type of winch was
used in the accident BGA 1991/20, or at Enstone in 1993.

W.J. (Bill) Dean (U.K.).
Remove "ic" to reply.

>
> "JS" > wrote in message
> ...
>
> What about changing the rotation direction of the cable reels, would it
> make the loose cable end hit the ground instead of drivers cabin?
>
> js
>

[Shawn Curry]

JS wrote:

>>Bill, excellent point!
>>
>>I have always considered the winch drivers job to be more dangerous than
>
> the
>
>>glider pilots. I tell people that each time I reach for the throttle, I
>>think about the 300 pounds of steel wire that is about to come straight at
>>me doing 70 MPH.
>>
>>Steel wire mesh or screen is totally inadequate to protect the driver.
>
> The
>
>>winch cab windows should be 3/4" polycarbonate (Lexan) which, I'm told,
>
> will
>
>>stop a 9mm bullet fired point blank. Yes, Lexan will get scratched
>>eventually but it's not that expensive to replace. The rest of the cab
>>should be at least .125 inch steel sheet.
>>
>>Spectra will reduce the danger somewhat but the rest of the hardware will
>>still be there and present the same dangers.
>>
>>I would prefer a winch cab that is armored, weather tight and air
>>conditioned.
>>
>>Bill Daniels
>>
>
>
> What about chanching the rotation direction of the cable reels, would it
> make the lose cable end hitting the ground instead of drivers cabin?
>
> js
>
>

Would Spectra or some other synthetic cable improve this? How much does
it stretch? My thought being that, there would still be a lot of energy
in a stretched light weight cable (imagine a 1000 foot rubber band
pointing at the driver) despite the lower weight and mass-to-drag while
falling.
Also, is the problem with steel wire/cable the elastic energy stored
from the launch, the mass of the falling steel, or a combination, that
creates the danger?

Shawn

[Bill Daniels]

"Shawn Curry" > wrote in message
news:9zE7c.58429$JL2.758827@attbi_s03...
> JS wrote:
>
> >>Bill, excellent point!
> >>
> >>I have always considered the winch drivers job to be more dangerous than
> >
> > the
> >
> >>glider pilots. I tell people that each time I reach for the throttle, I
> >>think about the 300 pounds of steel wire that is about to come straight
at
> >>me doing 70 MPH.
> >>
> >>Steel wire mesh or screen is totally inadequate to protect the driver.
> >
> > The
> >
> >>winch cab windows should be 3/4" polycarbonate (Lexan) which, I'm told,
> >
> > will
> >
> >>stop a 9mm bullet fired point blank. Yes, Lexan will get scratched
> >>eventually but it's not that expensive to replace. The rest of the cab
> >>should be at least .125 inch steel sheet.
> >>
> >>Spectra will reduce the danger somewhat but the rest of the hardware
will
> >>still be there and present the same dangers.
> >>
> >>I would prefer a winch cab that is armored, weather tight and air
> >>conditioned.
> >>
> >>Bill Daniels
> >>
> >
> >
> > What about chanching the rotation direction of the cable reels, would it
> > make the lose cable end hitting the ground instead of drivers cabin?
> >
> > js
> >
> >
>
> Would Spectra or some other synthetic cable improve this? How much does
> it stretch? My thought being that, there would still be a lot of energy
> in a stretched light weight cable (imagine a 1000 foot rubber band
> pointing at the driver) despite the lower weight and mass-to-drag while
> falling.
> Also, is the problem with steel wire/cable the elastic energy stored
> from the launch, the mass of the falling steel, or a combination, that
> creates the danger?
>
> Shawn

Spectra improves the situation a lot. The lack of "whipback" is the primary
reason the marine and construction industries have adopted Spectra as a
wholesale replacement for wire rope. Spectra stretches less than 1% before
failure and the stretch and recovery is so slow it is called "creep". The
"rubber band" concept just does not apply to Spectra.

Falling spectra poses no problem whatsoever (as long as it falls on the
airport) but the steel hardware does. There will still be carabiners and
weak links attached to the glider end of the rope that pose a danger.

Bill Daniels

[goneill]

Our club is using cheap ordinary polyprop rope ,there is no tendency at all
to
spring at the winch even with releases under tension.
The rope contracts into its own length.
gary
"Shawn Curry" > wrote in message
news:9zE7c.58429$JL2.758827@attbi_s03...
> JS wrote:
>
> >>Bill, excellent point!
> >>
> >>I have always considered the winch drivers job to be more dangerous than
> >
> > the
> >
> >>glider pilots. I tell people that each time I reach for the throttle, I
> >>think about the 300 pounds of steel wire that is about to come straight
at
> >>me doing 70 MPH.
> >>
> >>Steel wire mesh or screen is totally inadequate to protect the driver.
> >
> > The
> >
> >>winch cab windows should be 3/4" polycarbonate (Lexan) which, I'm told,
> >
> > will
> >
> >>stop a 9mm bullet fired point blank. Yes, Lexan will get scratched
> >>eventually but it's not that expensive to replace. The rest of the cab
> >>should be at least .125 inch steel sheet.
> >>
> >>Spectra will reduce the danger somewhat but the rest of the hardware
will
> >>still be there and present the same dangers.
> >>
> >>I would prefer a winch cab that is armored, weather tight and air
> >>conditioned.
> >>
> >>Bill Daniels
> >>
> >
> >
> > What about chanching the rotation direction of the cable reels, would it
> > make the lose cable end hitting the ground instead of drivers cabin?
> >
> > js
> >
> >
>
> Would Spectra or some other synthetic cable improve this? How much does
> it stretch? My thought being that, there would still be a lot of energy
> in a stretched light weight cable (imagine a 1000 foot rubber band
> pointing at the driver) despite the lower weight and mass-to-drag while
> falling.
> Also, is the problem with steel wire/cable the elastic energy stored
> from the launch, the mass of the falling steel, or a combination, that
> creates the danger?
>
> Shawn

[F.L. Whiteley]

Enstone 1993, ex-ATC winch chassis re-fitted with 6.7L Jag motor and
transmission.

Frank

"W.J. (Bill) Dean (U.K.)." > wrote in message
...
> I don't think the direction of rotation of the cable drums would make any
> difference. The damage is done by the energy in the moving wire. It
was
> not the loose end which went astray, it was a bight in the cable.
>
> With the Skylaunch winch the wire winds onto the bottom of the drum, with
> the Tost and many others onto the top. The two cases I knew about
> personally were with the Skylaunch, I do not know what type of winch was
> used in the accident BGA 1991/20, or at Enstone in 1993.
>
> W.J. (Bill) Dean (U.K.).
> Remove "ic" to reply.
>
> >
> > "JS" > wrote in message
> > ...
> >
> > What about changing the rotation direction of the cable reels, would it
> > make the loose cable end hit the ground instead of drivers cabin?
> >
> > js
> >
>
>
>
>
>
>
>
>

[John Firth]

"Bill Daniels" ) writes:
> "W.J. (Bill) Dean (U.K.)." > wrote in message
> ...
>> In discussions about winch design and construction, I think not enough
>> attention has been given to protecting the driver from the cable.
>>
>> This is a report about one accident (B.G.A. 1991/20):
after reading this I feel lucky to be alive, let alone uninjured.
In my first two years (58,59) at the Bristol GC I did a lot of winch driving
in a winch cobbled together from a lot of surplus stuff. Manual dry clutch,
tired old Ford V8 side valve, lightwieght mesh screen, open side panels
and a guillotine fo doubtful capability. Cable breaks were a 10%
probability; I thought contest flying was riskY!
>>
John Firth
old no longer bold etc.

>> "At the top of a normal winch launch the weak link failed and a fast
> moving
>> "snake" of cable fell onto the winch driver's cab. It found its way
>> through a narrow aperture in the wire mesh guard and hit the driver about
>> the head, nose, jaw and teeth. Fortunately he was only marked and not
>> badly cut. The club proposes to modify the guard."
>>
>> I know of another case where a "snake" of cable escaped from the drum,
> found
>> its way out of the drum cover, broke a window in the winch cab and
> attacked
>> the driver. It then disappeared back onto the drum leaving him to work
> out
>> what had happened. The driver was uninjured with torn clothing, he has
> not
>> driven the winch since. The drum cover has been improved.
>>
>> In a third case the wire broke, then whipped back behind the winch and
>> attacked the winch driver's car parked behind the winch (with the front of
>> the car towards the winch). It trashed the rear of the car and then
> wound
>> back round and broke one of the front door windows which was up. I saw
> the
>> car afterwards, I would not like to have been sitting in it when this
>> happened, especially if it was a warm day and the window was down! This
>> particular winch driver was very experienced at winching.
>>
>> All these incidents happened so quickly that there would have been no
> chance
>> to take cover.
>>
>> These dangers are much greater than most people realise. They do not
>> happen very often, but are you prepared to take the risk?
>>
>> W.J. (Bill) Dean (U.K.).
>> Remove "ic" to reply.
>>
>>
> Bill, excellent point!
>
> I have always considered the winch drivers job to be more dangerous than the
> glider pilots. I tell people that each time I reach for the throttle, I
> think about the 300 pounds of steel wire that is about to come straight at
> me doing 70 MPH.
>
> Steel wire mesh or screen is totally inadequate to protect the driver. The
> winch cab windows should be 3/4" polycarbonate (Lexan) which, I'm told, will
> stop a 9mm bullet fired point blank. Yes, Lexan will get scratched
> eventually but it's not that expensive to replace. The rest of the cab
> should be at least .125 inch steel sheet.
>
> Spectra will reduce the danger somewhat but the rest of the hardware will
> still be there and present the same dangers.
>
> I would prefer a winch cab that is armored, weather tight and air
> conditioned.
>
> Bill Daniels
>


--


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