Basejumper.com - archive

What's your opinion about jumping ff a windmill that is running? (of course on the opposite side :-)) Speaking about a 300 feet object in the middle of nowhere...

Your poll seems to present only a choice of nomenclature, not safety philosophy.

Not sure about different makes of turbines, but our local ones aren't accessible in wind unless that turbine is shut down. We have to crawl around on the gearbox to get through the top access door and can't while it's moving. I'm sure other makes are different. If you can get to the top while it's spinning, I'd say go for it! I mean you're jumping with the wind on your back anyway ;) might be a little rotor action going on back there.

I have never jumped a windmill/turbine that wasn't running.

The turbulence is really pretty minimal. Turbulence represents wasted energy, which the power engineers don't like. Their design goals line up quite nicely with our requirements.

we jump our local Turbine while its running all the time. Its kind of freaky because the turbine will regulate the amount of speed the blades are spinning so when it brakes the entire turbine sways forward and backwards. its weird because your balance while standing on top is all out of whack and feels like your standing on the roof of a moving car.

on ours there is a sign posted in the turbine housing that says no flash photography. assuming that means there are light sensors to defect if the electrical system starts sparking it will shut down. we only use red lights inside.

Same rules apply for winds as an A only you always get to jump in a tail wind

defiantly one of my favorite jumps.

same with our local swedish wind turbine.

If what you're doing would be stopped if the wrong person would find out, it might not be a good idea to talk about it publicly on the Internet, or at all outside your circle of trust.

It doesn't necessarily burn your object to talk about these things, but it does shine a light on something best kept in the dark and a systemic change might happen over time.

It's not hard to build doors that would require power tools or explosives in order to circumvent the locking mechanism. It's not hard to build access systems that would require access codes that changes over time instead of physical keys. It might not even cost more resources to do so. It's not hard to install alarm systems. It's not hard to check subscriber IDs from local cell towers and correlate that with other data, especially not in an area that's somewhat rural and the IMSI is not a part of the normal picture.

The only reason why these measures are not in effect today is because it's not considered necessary. Things can change very quickly. This is not a cliff in a country where cliffs are owned by the people. There's a lot of money and liability involved.

I know of people shutting down the wind turbines and burning the object. The maintenance guys get a call when it happens and after many times happening they changed the lock.

Really as Tom said behind the blades there should not be much wind/turbulence. But what do you think could happen just below the blades? You would be passing from an area of no wind to an area of wind in no time. If wind is low probably nothing but what about in moderate wind speeds?

I know of at least two people that have had violent, unexplainable canopy collapses on wind turbines... one broke a femur and one was lucky enough to walk away. I would be careful in assuming that there is no turbulence. Just because something is efficient, doesn't mean it doesn't create a lot of dirty, disturbed air in its wake.

in conjunction with what matt said here. turbines create a lot of turbulence. turbulence does not represent wasted energy, it represents a change in airflow direction and velocity. for proof of concept, stand behind on of the most efficient aerofoils in the world (the boeing 747) whilst it is landing. the wing is working at maximum efficiency at that point. i would assume you'd be tossed around 50 yards. :)

light aircraft have been downed by flying on the wrong side of a wind farm (yes they were too low) due to turbulence. an unloaded ram air parachute isn't going to be so kickass. that's just my opinion. meh. i'm probably wrong anyways.

The only time I have experienced severe turbulence on a wind turbine jump occurred when the electric motors were just starting up the blades in light wind conditions and it felt basically like jumping behind a running fan which was not fun but it worked out alright (the structure was also shaking violently).

Other than that I've jumped them in just about every condition from nil winds to probably about 25-30kt up top with no issues and even in high winds the canopy issues were really nothing greater than what one would expect on a high wind jump anyway and less than most urban jumps I've done. Of course if you have a large windfarm in the area I would recommend jumping one as upwind as possible just out of common sense. In the end though, every jump is a test jump and you are responsible for your own decisions and outcomes.

A good wind turbine extracts 2/3 of the energy from the wind, so you will experience the maximum wind shear (change in wind speed) as you pass from inside the wind cone, to outside the wind cone. IOW expect wind velocity to triple when you leave the wind-shadow of the turbine.
Flow at the outboard edge of the turbine is complex and turbulent.
That turbulence can extend 10 diameters down-wind of a turbine.