Cutting plasma rope

[Robert Makin]

There is considerable interest in the UK in using
plasma/dyneema rope for winch launching. However,
the main obstacle appears to be finding an efficient
method of cutting the rope in event of an emergency.
Has anyone ot there found the definitive method???

[tango4]

Hot wire/blade seems to be *the* method.

Perhaps a blade heated by the engine exhaust since an electrical system
might be subject to 'system bugs'. Actually its not such a stupid idea cone
to think of it. The blade/cutter mechanism needs to be on the glider side of
the winch and therefore downwind of the winch driver.

The only other solution I can think of is a blade that completes a circuit
across a primary battery when it is in the cutting position but that would
take a few seconds to heat up to the plasma melting point.

Has anyone contacted Marlow ropes in E. Sussex to find out what they
recommend? They manufacture Dynema cores sailing lines I think.

Ian

"Robert Makin" > wrote in message
...
> There is considerable interest in the UK in using
> plasma/dyneema rope for winch launching. However,
> the main obstacle appears to be finding an efficient
> method of cutting the rope in event of an emergency.
> Has anyone ot there found the definitive method???
>
>
>

[Gerritjan]

"Robert Makin" > wrote in message
...
> There is considerable interest in the UK in using
> plasma/dyneema rope for winch launching. However,
> the main obstacle appears to be finding an efficient
> method of cutting the rope in event of an emergency.
> Has anyone ot there found the definitive method???

I saw this message in another trhead named "Winch way is up":



You may want to have a look at
http://www.aec-landau.de/projekte/PE-Seil/vortrag.htm

They have modified their winch to cut their PE cable. You find the email
address of the author at the end of that page.
Eggert

[Dave Martin]

Cutting Plasma rope

Skylaunch UK HAVE developed equipment that will cut
plasma rope succesfully.

A number of UK clubs have expressed interest in the
use of this rope which has reportedly many benefits
over steel, except perhaps on cost.

What is required is some proving tests in the UK to
ensure that not only are the claims valid BUT that
it can be used safely within the terms of UK Health
and Safety Legislation AND that is benefits are cost
effective.

Offers are on the table for a winch to be made available
to be modified to take the cutting gear and for a reduce
cost rope for the tests. Less than £1000 at the last
enquiry.

The UK research appears to have gone as far as it can
without someone forking out some cash for it to continue.

The equipment and offers of free help and involvement
are at present on the table.

If UK clubs, who want the benefits but not the cost,
want this to progress then someone has to dig into
their pocket. If several clubs pool their resources
the work can progress

Sadly at present no UK clubs want to part with a few
hundred quid to support the research.

That is where it stands in the UK.

Dave Martin

[Ian Forbes]

On Sun, 02 Nov 2003 09:27:15 +0000, tango4 wrote:

> Perhaps a blade heated by the engine exhaust

Maybe in an emergency the winch driver could climb out of the cab, grab
hold of the (hopefully stationery) plasma rope and pull it over a hot
exhaust pipe to cut it. Worth thinking about if you fortunate enough to
winch with plasma.

We have a set of bolt cutters mounted in the winch cab to function as a
backup to cut our steel cable in the unlikely event that the winch
guillotine fails to function in an emergency. It is part of the equipment
that must be present on the winch before launching commences. (Normally
they only get used for cutting off scrap cable after a tangle on the
drum).

Cheers

Ian

[Bob Johnson]

Hi Dave --

Thanks for the heads up. One question: Does the UK guillotine
specification include the necessity for cutting a moving synthetic line,
or would cutting a stationary line be satisfactory?

Thanks.

Bob Johnson

Dave Martin wrote:

> Cutting Plasma rope
>
> Skylaunch UK HAVE developed equipment that will cut
> plasma rope succesfully.
>
> A number of UK clubs have expressed interest in the
> use of this rope which has reportedly many benefits
> over steel, except perhaps on cost.
>
> What is required is some proving tests in the UK to
> ensure that not only are the claims valid BUT that
> it can be used safely within the terms of UK Health
> and Safety Legislation AND that is benefits are cost
> effective.
>
> Offers are on the table for a winch to be made available
> to be modified to take the cutting gear and for a reduce
> cost rope for the tests. Less than £1000 at the last
> enquiry.
>
> The UK research appears to have gone as far as it can
> without someone forking out some cash for it to continue.
>
> The equipment and offers of free help and involvement
> are at present on the table.
>
> If UK clubs, who want the benefits but not the cost,
> want this to progress then someone has to dig into
> their pocket. If several clubs pool their resources
> the work can progress
>
> Sadly at present no UK clubs want to part with a few
> hundred quid to support the research.
>
> That is where it stands in the UK.
>
> Dave Martin
>
>

[Dave Martin]

At 16:30 03 November 2003, Bob Johnson wrote:
>Hi Dave --
>
>Thanks for the heads up. One question: Does the UK
>guillotine
>specification include the necessity for cutting a moving
>synthetic line,
>or would cutting a stationary line be satisfactory?
>
>Thanks.
>
>Bob Johnson

Hi Bob

Thanks for the interest.

Without getting the BGA winch manual out the answer
to your question is yes. In practice the guillotines
are required to cut both stationary and moving cables.


I have not seen the new Skylaunch equipment in action,
but I am told the cut is on a stationary rope. The
experts tell me this is the most difficult way to cut
rope and that a rope moving under tension is easier
to cut.

This is partly the reason we need to carry out load,
flight and cutting tests in a live situation. If only
to satisfy ourselves.

Dave Martin

[Bob Johnson]

Hello Dave --

Regarding the moving line, can you think of a situation where the winch
driver, upon becoming aware of an emergency situation, would want or
need to keep the line coming in?

You can see where this is leading: If the line can be stopped, why
couldn't the operator jump out of his cab and cut the synthetic line
with a sharp knife?

Or do you think this action would somehow place him in danger?

BJ

Dave Martin wrote:
>
> At 16:30 03 November 2003, Bob Johnson wrote:
> >Hi Dave --
> >
> >Thanks for the heads up. One question: Does the UK
> >guillotine
> >specification include the necessity for cutting a moving
> >synthetic line,
> >or would cutting a stationary line be satisfactory?
> >
> >Thanks.
> >
> >Bob Johnson
>
> Hi Bob
>
> Thanks for the interest.
>
> Without getting the BGA winch manual out the answer
> to your question is yes. In practice the guillotines
> are required to cut both stationary and moving cables.
>
> I have not seen the new Skylaunch equipment in action,
> but I am told the cut is on a stationary rope. The
> experts tell me this is the most difficult way to cut
> rope and that a rope moving under tension is easier
> to cut.
>
> This is partly the reason we need to carry out load,
> flight and cutting tests in a live situation. If only
> to satisfy ourselves.
>
> Dave Martin
>
>

[Marcel Duenner]

Bob Johnson > wrote in message >...
> Hello Dave --
>
> Regarding the moving line, can you think of a situation where the winch
> driver, upon becoming aware of an emergency situation, would want or
> need to keep the line coming in?

Can't really think of one. But we are talking about an emergency
situation here so anything can be possible.

>
> You can see where this is leading: If the line can be stopped,...

Can it? Before you were talking about 'want to' and 'need to'. That's
not the same. I can imagine situations where the cable cannot be
stopped or starts moving again.

>... why
> couldn't the operator jump out of his cab and cut the synthetic line
> with a sharp knife?

Again: Cutting the winch cable is an emergency. Why on earth would you
want to lose time jumping from the winch and looking for your cutting
tool?

>
> Or do you think this action would somehow place him in danger?

Yes it could. See above.

BTW: In my 18 seasons of gliding I am not aware of the winch cable
ever been cut in an emergency. And that's in about 70'000 launches.

Regards
Marcel

[goneill]

>
> BTW: In my 18 seasons of gliding I am not aware of the winch cable
> ever been cut in an emergency. And that's in about 70'000 launches.
>
> Regards
> Marcel

Our club had an instance recently where it was required to cut the cable
but the pilot did some radical flying (75degree nose down in a ventus a
at 700 feet) he let go of the stick and used both hands on the release
and the cable came off.
This ventus had been backreleasing for some time and an "adjustment"
was done but the backrelease angle was now somewhere near the wheel
centre.
One shaken pilot and one big lesson .
One senior pilot of 45 yrs 11000hrs said he had never seen a hangup
in all his flying.

[Dave Martin]

Bob

I think Marcel answered your questions

I can think of and know of instances where the winch
driver should cut the cable instantly, moving or stationary.

Should -- must -- need -- want -- ought to cut the
cable are all subjective and cannot be answered fully
in the space available. Ultimately I suppose on which
side of the incident you are sitting, on the winch
or in the air and the final outcome.

I witnessed an incident where the pilot on a winch
launch failed to take the correct action when travelling
too fast, he released and accelerated flying under
the cable which then wrapped itself round the glider.
Removed the tail plane and embedded itself in the
fin

The glider did a neat 180 and then dived at about 45
degrees earthwards. The winch driver did not cut the
cable. Just before the glider hit the ground, the winch
cable pulled tight and stopped the glider in mid air.
It 'landed' with greatly reduce forward speed and
energy. It hit the ground almost flat.

The glider was wrecked but the pilot lived.

Talking to the winch driver afterward, he failed to
cut the cable because events happened so fast, he froze.
It was probably all over in less than 10 seconds.

Whatever the incident, the winch driver MUST have the
facility to cut the rope. Only hindsight will tell
whether he should have or should not have cut the cable.


The answer to the problem is training the brain on
each end of the wire to treat the wire and the winch
with utmost respect.

Dave Martin

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

As I am sure Dave Martin knows there was another accident in the U.K. where
the cable got round the glider's wing after the glider had released it.

The winch driver operated the cutter while the glider was still drawing the
cable out, which did not succeed in cutting the cable; the winch driver was
left with nothing else he could do, then the cable hung up, tightened, and
the pilot was killed.

So here was a case where it was necessary to cut the cable when it was
moving.

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

>
> "Dave Martin" > wrote in message
> ...
>
> Bob
>
> I think Marcel answered your questions
>
> I can think of and know of instances where the winch
> driver should cut the cable instantly, moving or stationary.
>
> Should -- must -- need -- want -- ought to cut the
> cable are all subjective and cannot be answered fully
> in the space available. Ultimately I suppose on which
> side of the incident you are sitting, on the winch
> or in the air and the final outcome.
>
> I witnessed an incident where the pilot on a winch
> launch failed to take the correct action when travelling
> too fast, he released and accelerated flying under
> the cable which then wrapped itself round the glider.
> Removed the tail plane and embedded itself in the
> fin
>
> The glider did a neat 180 and then dived at about 45
> degrees earthwards. The winch driver did not cut the
> cable. Just before the glider hit the ground, the winch
> cable pulled tight and stopped the glider in mid air.
> It 'landed' with greatly reduce forward speed and
> energy. It hit the ground almost flat.
>
> The glider was wrecked but the pilot lived.
>
> Talking to the winch driver afterward, he failed to
> cut the cable because events happened so fast, he froze.
> It was probably all over in less than 10 seconds.
>
> Whatever the incident, the winch driver MUST have the
> facility to cut the rope. Only hindsight will tell
> whether he should have or should not have cut the cable.
>
> The answer to the problem is training the brain on
> each end of the wire to treat the wire and the winch
> with utmost respect.
>
> Dave Martin
>

[Bob Johnson]

Hello Bill --

In an attempt to summarize the search for an effective synthetic rope
guillotine then, I would say that we are expecting to develop an
emergency line cutter at least as effective and safe as those we
already employ against steel lines, stranded and solid, moving and
stationary.

Since the numerous winch builders and users on your side of the pond
will by necessity be building and rigorously testing an ideal unit
fairly soon, we'll be interested in learning of your solution(s) to the
problem!

I personally favor trying a "cigar cutter" powered by a compressed gas
cylinder. The cutting blade could be veed to gather the line into the
stationary blade and suitable finger guards can be added to prevent
injuries. The actuating cylnder diameter can be made as large as
necessary to multiply the bottle force enough to secure a successful
cut. Also, at least two units could be installed to provide a backup.

In the oilfield we use diaphragm operated rising stem valves that could
be adapted for trials by developing a new valve "trim". A typical 6-inch
diaphragm valve would have about 25 sq in of area. Powered by only a 100
psi cylinder, around 2500 lb of downward force would be available to the
descending stem. That ought to cut something.

A plus is that the valve body could have short pipe nipples screwed onto
each end, rendering personal injuries a non-issue. These nipples could
also be used to secure the unit the the winch by use of heavy duty pipe
clamps. Finally,the higher the pressure, the larger the gas cylinder and
the smaller the diaphragm, the faster the unit would operate.

BJ

"W.J. (Bill) Dean (U.K.)." wrote:
>
> As I am sure Dave Martin knows there was another accident in the U.K. where
> the cable got round the glider's wing after the glider had released it.
>
> The winch driver operated the cutter while the glider was still drawing the
> cable out, which did not succeed in cutting the cable; the winch driver was
> left with nothing else he could do, then the cable hung up, tightened, and
> the pilot was killed.
>
> So here was a case where it was necessary to cut the cable when it was
> moving.
>
> W.J. (Bill) Dean (U.K.).
> Remove "ic" to reply.
>
> >
> > "Dave Martin" > wrote in message
> > ...
> >
> > Bob
> >
> > I think Marcel answered your questions
> >
> > I can think of and know of instances where the winch
> > driver should cut the cable instantly, moving or stationary.
> >
> > Should -- must -- need -- want -- ought to cut the
> > cable are all subjective and cannot be answered fully
> > in the space available. Ultimately I suppose on which
> > side of the incident you are sitting, on the winch
> > or in the air and the final outcome.
> >
> > I witnessed an incident where the pilot on a winch
> > launch failed to take the correct action when travelling
> > too fast, he released and accelerated flying under
> > the cable which then wrapped itself round the glider.
> > Removed the tail plane and embedded itself in the
> > fin
> >
> > The glider did a neat 180 and then dived at about 45
> > degrees earthwards. The winch driver did not cut the
> > cable. Just before the glider hit the ground, the winch
> > cable pulled tight and stopped the glider in mid air.
> > It 'landed' with greatly reduce forward speed and
> > energy. It hit the ground almost flat.
> >
> > The glider was wrecked but the pilot lived.
> >
> > Talking to the winch driver afterward, he failed to
> > cut the cable because events happened so fast, he froze.
> > It was probably all over in less than 10 seconds.
> >
> > Whatever the incident, the winch driver MUST have the
> > facility to cut the rope. Only hindsight will tell
> > whether he should have or should not have cut the cable.
> >
> > The answer to the problem is training the brain on
> > each end of the wire to treat the wire and the winch
> > with utmost respect.
> >
> > Dave Martin
> >

[Dave Martin]

Hi Bob

I do not think we have numerous winch builders on this
side of the pond, possibly four in Europe.

Before we get into expensive guillotines we need to
prove the cable with the kit we have. Part of the
cost effective equation would be installing new guillotines
on existing winches. Possibly developing a graft on
guillotine so the winch can use either steel or synthetic.
I don't see a major technical problem with this just
an expense that may prevent clubs from adopting the
rope

But first let us prove the cable.

Dave


PS I can report that I have had several generous offers
of financial help. A few more and we could be looking
at a realistic project.

Dave



>In an attempt to summarize the search for an effective
>synthetic rope
>guillotine then, I would say that we are expecting
>to develop an
>emergency line cutter at least as effective and safe
>as those we
>already employ against steel lines, stranded and solid,
>moving and
>stationary.
>
>Since the numerous winch builders and users on your
>side of the pond
>will by necessity be building and rigorously testing
>an ideal unit
>fairly soon, we'll be interested in learning of your
>solution(s) to the
>problem!
>
>I personally favor trying a 'cigar cutter' powered
>by a compressed gas
>cylinder. The cutting blade could be veed to gather
>the line into the
>stationary blade and suitable finger guards can be
>added to prevent
>injuries. The actuating cylnder diameter can be made
>as large as
>necessary to multiply the bottle force enough to secure
>a successful
>cut. Also, at least two units could be installed to
>provide a backup.
>
>In the oilfield we use diaphragm operated rising stem
>valves that could
>be adapted for trials by developing a new valve 'trim'.
>A typical 6-inch
>diaphragm valve would have about 25 sq in of area.
>Powered by only a 100
>psi cylinder, around 2500 lb of downward force would
>be available to the
>descending stem. That ought to cut something.
>
>A plus is that the valve body could have short pipe
>nipples screwed onto
>each end, rendering personal injuries a non-issue.
>These nipples could
>also be used to secure the unit the the winch by use
>of heavy duty pipe
>clamps. Finally,the higher the pressure, the larger
>the gas cylinder and
>the smaller the diaphragm, the faster the unit would
>operate.
>
>BJ
>
>>

[Bob Johnson]

Hello Dave-

This is an extreme statement, so I make it in jest, but I could build
something out of balsa wood that would serve when someone asked if I
have a guillotine, I could reply with some confidence, "Yes, I have a
guillotine"! 8>)

BJ

Dave Martin wrote:
>
> Hi Bob
>
> I do not think we have numerous winch builders on this
> side of the pond, possibly four in Europe.
>
> Before we get into expensive guillotines we need to
> prove the cable with the kit we have. Part of the
> cost effective equation would be installing new guillotines
> on existing winches. Possibly developing a graft on
> guillotine so the winch can use either steel or synthetic.
> I don't see a major technical problem with this just
> an expense that may prevent clubs from adopting the
> rope
>
> But first let us prove the cable.
>
> Dave
>
> PS I can report that I have had several generous offers
> of financial help. A few more and we could be looking
> at a realistic project.
>
> Dave
>
> >In an attempt to summarize the search for an effective
> >synthetic rope
> >guillotine then, I would say that we are expecting
> >to develop an
> >emergency line cutter at least as effective and safe
> >as those we
> >already employ against steel lines, stranded and solid,
> >moving and
> >stationary.
> >
> >Since the numerous winch builders and users on your
> >side of the pond
> >will by necessity be building and rigorously testing
> >an ideal unit
> >fairly soon, we'll be interested in learning of your
> >solution(s) to the
> >problem!
> >
> >I personally favor trying a 'cigar cutter' powered
> >by a compressed gas
> >cylinder. The cutting blade could be veed to gather
> >the line into the
> >stationary blade and suitable finger guards can be
> >added to prevent
> >injuries. The actuating cylnder diameter can be made
> >as large as
> >necessary to multiply the bottle force enough to secure
> >a successful
> >cut. Also, at least two units could be installed to
> >provide a backup.
> >
> >In the oilfield we use diaphragm operated rising stem
> >valves that could
> >be adapted for trials by developing a new valve 'trim'.
> >A typical 6-inch
> >diaphragm valve would have about 25 sq in of area.
> >Powered by only a 100
> >psi cylinder, around 2500 lb of downward force would
> >be available to the
> >descending stem. That ought to cut something.
> >
> >A plus is that the valve body could have short pipe
> >nipples screwed onto
> >each end, rendering personal injuries a non-issue.
> >These nipples could
> >also be used to secure the unit the the winch by use
> >of heavy duty pipe
> >clamps. Finally,the higher the pressure, the larger
> >the gas cylinder and
> >the smaller the diaphragm, the faster the unit would
> >operate.
> >
> >BJ
> >
> >>

[goneill]

Has anyone approached the rope suppliers for some developement funding
I would think that to enlarge their market that some funds could be
allocatted
possibly from their advertising budget since they don't have to advertise to
gain
clients.
gary
"Bob Johnson" > wrote in message
...
> Hello Bill --
>
> In an attempt to summarize the search for an effective synthetic rope
> guillotine then, I would say that we are expecting to develop an
> emergency line cutter at least as effective and safe as those we
> already employ against steel lines, stranded and solid, moving and
> stationary.
>
> Since the numerous winch builders and users on your side of the pond
> will by necessity be building and rigorously testing an ideal unit
> fairly soon, we'll be interested in learning of your solution(s) to the
> problem!
>
> I personally favor trying a "cigar cutter" powered by a compressed gas
> cylinder. The cutting blade could be veed to gather the line into the
> stationary blade and suitable finger guards can be added to prevent
> injuries. The actuating cylnder diameter can be made as large as
> necessary to multiply the bottle force enough to secure a successful
> cut. Also, at least two units could be installed to provide a backup.
>
> In the oilfield we use diaphragm operated rising stem valves that could
> be adapted for trials by developing a new valve "trim". A typical 6-inch
> diaphragm valve would have about 25 sq in of area. Powered by only a 100
> psi cylinder, around 2500 lb of downward force would be available to the
> descending stem. That ought to cut something.
>
> A plus is that the valve body could have short pipe nipples screwed onto
> each end, rendering personal injuries a non-issue. These nipples could
> also be used to secure the unit the the winch by use of heavy duty pipe
> clamps. Finally,the higher the pressure, the larger the gas cylinder and
> the smaller the diaphragm, the faster the unit would operate.
>
> BJ
>
> "W.J. (Bill) Dean (U.K.)." wrote:
> >
> > As I am sure Dave Martin knows there was another accident in the U.K.
where
> > the cable got round the glider's wing after the glider had released it.
> >
> > The winch driver operated the cutter while the glider was still drawing
the
> > cable out, which did not succeed in cutting the cable; the winch driver
was
> > left with nothing else he could do, then the cable hung up, tightened,
and
> > the pilot was killed.
> >
> > So here was a case where it was necessary to cut the cable when it was
> > moving.
> >
> > W.J. (Bill) Dean (U.K.).
> > Remove "ic" to reply.
> >
> > >
> > > "Dave Martin" > wrote in message
> > > ...
> > >
> > > Bob
> > >
> > > I think Marcel answered your questions
> > >
> > > I can think of and know of instances where the winch
> > > driver should cut the cable instantly, moving or stationary.
> > >
> > > Should -- must -- need -- want -- ought to cut the
> > > cable are all subjective and cannot be answered fully
> > > in the space available. Ultimately I suppose on which
> > > side of the incident you are sitting, on the winch
> > > or in the air and the final outcome.
> > >
> > > I witnessed an incident where the pilot on a winch
> > > launch failed to take the correct action when travelling
> > > too fast, he released and accelerated flying under
> > > the cable which then wrapped itself round the glider.
> > > Removed the tail plane and embedded itself in the
> > > fin
> > >
> > > The glider did a neat 180 and then dived at about 45
> > > degrees earthwards. The winch driver did not cut the
> > > cable. Just before the glider hit the ground, the winch
> > > cable pulled tight and stopped the glider in mid air.
> > > It 'landed' with greatly reduce forward speed and
> > > energy. It hit the ground almost flat.
> > >
> > > The glider was wrecked but the pilot lived.
> > >
> > > Talking to the winch driver afterward, he failed to
> > > cut the cable because events happened so fast, he froze.
> > > It was probably all over in less than 10 seconds.
> > >
> > > Whatever the incident, the winch driver MUST have the
> > > facility to cut the rope. Only hindsight will tell
> > > whether he should have or should not have cut the cable.
> > >
> > > The answer to the problem is training the brain on
> > > each end of the wire to treat the wire and the winch
> > > with utmost respect.
> > >
> > > Dave Martin
> > >

[Dave Martin]

At 18:48 04 November 2003, Goneill wrote:
>Has anyone approached the rope suppliers for some developement
>funding
>I would think that to enlarge their market that some
>funds could beallocatted possibly from their advertising
budget since they don't have to advertise to gain clients.
>gary

I have approached the UK importer and he looking into
this prospect and other avenues are being tried

Dave

[CH]

the gliding school Oerlinghausen in Germany
is using the plasma cable as well. I was told,
that a small modifiaction of the capping
system did the trick, but I have no details.
Chris


"Robert Makin" > wrote in message
...
> There is considerable interest in the UK in using
> plasma/dyneema rope for winch launching. However,
> the main obstacle appears to be finding an efficient
> method of cutting the rope in event of an emergency.
> Has anyone ot there found the definitive method???
>
>
>

[soarski]

I translated the important part off a Winch Homepage from German. in
one of the other threads!

They modify the Guilutine so it comes down on a brass anvil,over which
the rope is running. The cutting device, probably something like a big
knife,more like chopping than a shearing action.

Dieter







"CH" > wrote in message >...
> the gliding school Oerlinghausen in Germany
> is using the plasma cable as well. I was told,
> that a small modifiaction of the capping
> system did the trick, but I have no details.
> Chris
>
>
> "Robert Makin" > wrote in message
> ...
> > There is considerable interest in the UK in using
> > plasma/dyneema rope for winch launching. However,
> > the main obstacle appears to be finding an efficient
> > method of cutting the rope in event of an emergency.
> > Has anyone ot there found the definitive method???
> >
> >
> >