Every now and then I see a collection of wind turbines in the countryside. All of these collections look the same: single central support post, three blades, and they all appear to be the same gigantic size. I occasionally see parts being hauled down the interstate, and they’re incredibly big. The blades appear to be as long as a couple of standard 53’ trailers, and the post segments are perhaps 15’ in diameter. But that’s just an eyeball guess.
Is there one manufacturer who is making all of these? What are the real dimensions for these beasts?
There are many manufacturers, and many sizes. Several years ago I had a job building windmill blades with a major global blade manufacturer, and the smallest blades we made were around 14m from root to tip, and the largest were 61m. At the time, those were the world’s largest. I believe the current record holder is 75m.
As I understand it, some turbines now being built are more than 200 metres tall (I imagine this is measured as the height from ground to the tip of one blade when it is pointing vertically upward).
One thing that is standard about wind turbines: The blades are shorter than the pylon
I looked at many* Wikipedia pages and none of them said what “root” meant. Is that the end of an individual blade on the other side of the axle? How far from the center of rotation is that for those longer blades?
For an airplane wing, the “root” is where it attaches to the fuselage. Likewise, for a wind turbine, the “root” is where the blade attaches to the hub.
Correct, the root of a blade or wing is the end which is affixed to the rest of the structure. So to come up with a turbine radius, you need to know the radius of the hub. Something like 5m seems reasonable, which would give a radius of 80m and an overall diameter of 160m. Some of these things are HUGE.
ETA: Wiki says the largest diameter rotor is 154m and the tallest turbine is 210m.
I work for a small company investigating the use of novel polymers in wind turbine blades, and so I’ve become quite familiar with the larger blade manufacturers. Off the top to my head, there are
and many more, I’m sure. I doubt that the measurements are standardized among the companies.
My understanding is that the blades are manufactured in segments (for example, top and bottom like a clam shell) and fastened together with some sort of polymer adhesive. I don’t know if this assembly happens at the factory or on site. Perhaps they float the offshore ones to the turbine location. Do you see full blades moving down the freeway? That sounds quite… difficult.
How does the meaning of “root” obviously follow from the other end being “tip”? Not knowing the airplane meaning, “root” could just as easily have meant the far side of the hub, or the center of rotation of the blades.
In Google Earth at (40.3222, -3.6914) there is storage facility for blades and trucks which can be seen in street view from five lanes of highway, each one with different date recorded. From here I often see blades being moved by road. Sometimes on a “telescopic” truck. Sometimes, when the telescopic truck is not long enough the last part of the blade (tip) is loose and vibrates in the air but underneath it is a trailer which is just there to prevent any vehicle from getting underneath, it does not touch or support the blade in any way. There is always small vehicles with flashing lights, one in front and one following.
My shop is on a 2 lane state route parallel with I 90 in upstate New York, we have 2 garage doors facing the street, kept open except for foul weather. We see oversized loads with escorts going by all the time.
Using my Mark 1 calibrated eyeball I know a standard semi trailer is 53 feet. I’ve seen dozens of flatbed trailers go by with blades on them that look to be 40 to 75 feet long. Seem to be assembled and ready to bolt onto a hub.
It is difficult, but the freeway is the easiest part. My company has taken delivery of blades in Dublin port which had to be driven through the city, including crossing a bridge over the Liffey. The bridge had to be closed to all other traffic for several hours and cleared of street furniture to allow the trucks to make the turn, which was done in the middle of the night.
At the other end of the journey, the blades have to be transported along narrow rural roads to the wind farm site. Often the roads have to be remade and small bridges realigned or reinforced to allow the load to reach its destination.
The trucks used have steerable rear wheels, which helps when driving on narrow and winding roads.
Once the blade halves are completed, they are joined while still in their molds. Adhesive is spread around the edges and on the structural webs (it’s actually pumped from 55 gallon drums), and the top mold is hydraulically closed over the bottom mold (sort of like a gigantic sunglasses case). It’s held in place until the adhesive is cured, then the mold is opened and the entire blade is removed with overhead cranes. The shape and structure of the blade are set at this point, but there is still quite a bit of work to be done before it goes out the door.
There’s an image of a partially opened mold, here. You’re looking at the root end of the mold, which is probably quite a bit larger than it appears. If I had to guess, I’d bet that blade root has a 2m radius, but that’s a WAG.
Applied to a tapering object, “tip” strongly suggests the small, “pointed”, distal end. If the opposite is known as the “root”, this must refer to the fat, “attached”, proximal end.
I don’t see how you can say the other end must be where it attaches. As I already said, unless you already know the jargon, “root” could as easily have referred to the far side of the hub, or to the axis.
It’s not like this usage of root shows up all over the place. Searching for “root tip taper object” doesn’t bring up much in the way of examples. Certainly, the most common usage of “root” refers to plants, and there it means the part under the ground. Not the location where the plant enters the ground.
This started with StrangerThanFiction’s remark “the smallest blades we made were around 14m from root to tip” - which seems clearly to imply that “root” is the name of one end of a blade and “tip” is the name of the other. These are terms applicable to the blade itself - it need not be mounted.
