land-speed
[Top] [All Lists]

Re: Parachute

To: "DOUG ODOM" <popms@thegrid.net>
Subject: Re: Parachute
From: "Jim Dincau" <jdincau@qnet.com>
Date: Sun, 5 Nov 2000 17:25:20 -0800
Doug,
I think the problem is one of implementation. Reefer cutters used in the
military/aerospace are pyrotechnic devises that are built with a
predetermined delay. The right delay is achieved by lots of experimentation
and is different for each application, i.e. extracting jeeps from a C-130 VS
Trucks from a C-141. In addition pyrotechnic devices don't lend themselves
to safe operation by amateurs if you know what I mean. Throw in the
conditions of being packed in a chute that is salty I don't think electronic
or pyro gadgets are in the cards for the average chute user. This wouldn't
preclude their use on an operation that could include persons of the right
technical bent to oversee their use.
Jim in Palmdale

----- Original Message -----
From: DOUG ODOM <popms@thegrid.net>
To: Jim Dincau <jdincau@qnet.com>
Cc: <land-speed@autox.team.net>
Sent: Sunday, November 05, 2000 8:04 AM
Subject: Re: Parachute


> Jim; Would that system (reefed) work on a LSR vehicle? If so why  is it
> not being used?     Doug
>
> Jim Dincau wrote:
> >
> > Doug,
> > The chute when it blossoms is in a "reefed" condition. A line holds the
> > shroud lines close together where they connect to the canopy. After a
delay
> > this line is cut and the chute opens fully. This technique is used in a
lot
> > of instances when dealing with heavy loads.
> > Jim in Palmdale , who once worked at a place that manufactured "reefer
> > cutter" charges.
> >
> > ----- Original Message -----
> > From: DOUG ODOM <popms@thegrid.net>
> > To: Wester S Potter <wspotter@jps.net>
> > Cc: <land-speed@autox.team.net>
> > Sent: Sunday, November 05, 2000 7:16 AM
> > Subject: Re: Parachute
> >
> > > Wes; My $.02 worth. The big difference between drag cars and LSR cars
> > > is the size of the tire you have on the ground and the weight of the
> > > car. I don't know of many drag cars that run 7 or 8 hundred pounds of
> > > ballast. On the really fast LSR cars I would think they would copy the
> > > Air Force or space shuttle type of parachute deployment. The other day
> > > on TV I saw the space shuttle land and the chute was out before the
> > > wheels touched the ground but it looked like it was rolled up so it
> > > unfurled and got bigger the longer it was out. Is this a way to soften
> > > the hit?
> > > Doug Odom in big ditch
> > >
> > > Wester S Potter wrote:
> > > >
> > > > List,
> > > >
> > > > This braking parachute question always leaves me wondering why the
drag
> > > > racers can slow from 300 mph passes with a parachute time after time
> > without
> > > > very many incidents.  What is the big difference in slowing from 300
at
> > a
> > > > drag strip and slowing from 380 or so on the salt?  I'm sure I'm
missing
> > the
> > > > point here somewhere but something is at work on tethers and chute
> > design
> > > > for land-speed applications that is primarily solved in drag racing.
> > The
> > > > discussion early this year on how to find the optimum point for
placing
> > a
> > > > tether connection made sense as I read it.  The cars that have
problems
> > on
> > > > the salt are primarily placing that connection in the wrong place
and
> > > > disturbing the balance of the car at speed.  I realize that drag
cars
> > differ
> > > > so little that once someone gets it right it's easy for everyone to
do
> > the
> > > > same thing.  Not so with land-speed cars.  The basilc ability of
getting
> > the
> > > > parachute to deploy and do it's job seems to be the same however.
The
> > > > tether straps are able to handle the same loads on dragsters, ribbon
> > chutes
> > > > and the cross panel chutes hold up, what is so different on the
salt?
> > The
> > > > Burkland's car certainly had enough thought in the design area  for
> > braking
> > > > but now Tom has gone back to the drawing board to see what he
missed.
> > > > Obviously the deployment of the chutes was at speeds higher than he
had
> > > > intended.  What's the answer?
> > > >
> > > > Wes

<Prev in Thread] Current Thread [Next in Thread>