Blade lifter: from dream to reality

This post is a follow up of my other post on the blade lifter.

When I’ve been discussing about this solution with the other guy in the business 3 or 4 years ago, they told me it was something utopic, a “nice to have, but still a dream”.

Well, apparently now the blade lifter arrived, and it’s here to stay - and with a more aggressive configuration.

We’ve used it in a project in central America together with GES, a company specialized in wind and solar project, who bought one.

I’ve also discovered that another transport company in Italy (SIA – they are specialized in WTGs components transport) bought one in August 2014.

Clearly, this unlock the power of the blade lifter in Europe: I’m sure that in some complicated situations, it will make sense to move it from a country to the other.

There is a very good post on the company web describing this solution – have a look.

They’ve also done a very professional video (embedded in this post).

Resuming the key features:

 

  • Produced by Scheuerle
  • Maximum angle 60°
  • Maximum capacity is 25 tons
  • Maximum slope: 23% (paved road) / 18% (dirt road)
  • Wireless wheel remote control

 

Enjoy the video!

Wind blade special transport: 45 degrees lifter for montainous roads

This is a blade special transport system that I’ve seen used by Enercon, for instance for Europe highest wind turbine in Europe, in Switzerland, but is not so common otherwise.

It is a hydraulic lifter, which allows lifting the wind blade up to approximately 45º.

Doing so it can guarantee important saving on the civil works, above all in mountainous areas where important earthworks have to be realized to reach the wind park.

It has to be used together with a 5 axle low loader, and its price is around 100.000€.

The biggest problem is that in many countries it couldn’t be used on the public roads, due to restriction the maximum height of the load (around 5 meters).

By the way I guess that special permit are granted in some countries (for instance I’ve seen several picture where this solution was used in public roads in Germany and Switzerland).

Nooteboom special trailers PDF and AutoCAD blocks

Royal Nooteboom Trailers is a Dutch company dedicated to special transport: flatbed trailers, low loaders and other amazing wind related vehicles.

They have developed several solutions for the transport of nacelles, tower sections and blades. Among their products, the MEGA wind mill transporter (for towers and nacelles) and the several families of blades trailers.

Nooteboom Teletrailers have an extendable load floor, single, double or triple extendible. They can go from 13,6 closed to 42 meters totally extended, or from16,6 closed to 48 meters totally extended,

Special tailored solutions can be developed for transport of blades over 50 meters.

They allow remote controlled, independent rear wheels steering, a really useful functionality to choose the best trajectory in complicated environments.

One of they last invention is the Tele-Step, specially designed for very long blades (50+ meters), with a peculiar turn table mechanism below the blade that permits movements otherwise impossible.

Another interesting product, the MEGA wind mill transporter, can load and unload the tower or nacelle without the help of a crane. It consists of 2 hydraulically adjustable lift-adapters that can be universally employed on various vehicle types. The lift-adapters are connected to the semi-trailers by means of a turntable, and the load can be rotated up to 80 degrees. The outstanding maneuverability is due to the fact that the swept path covered is determined by the size of the load only and not by the steering behavior of the vehicle. Pretty amazing.

It’s not easy to find technical drawings of their products online, so I’ve decided to share with the rest of the world several PDF / DWG from my private collection.

PDF

AutoCAD blocks

AutoTURN special transport simulation: pros and cons

Working in Vestas at dozen of wind farms worldwide I’ve had the opportunity to use frequently AutoTURN to simulate bends and other complicated maneuvers (for instance in towns or near existing structures) with special transports (mainly wind blades and tower section trailers).

Although it is not cheap (the price was almost 1800 € plus VAT: a lot of money, considering that it’s an AutoCAD plug in) I am satisfied with the software.

The main advantage is that you can check very quickly if you’re going to have a problem somewhere, even if you don’t have a topography (sometimes we work with a blurry Google Earth picture). It is very easy to use and intuitive at the beginning, and it includes the rear wheels remote control used nowadays.

Main drawbacks: there are only a few special vehicles for wind components transport in the library, so you have to make your own. I’ve replicated several Nooteboom trailers, as we often works with them, using the “personalized vehicle” feature.

Moreover it is not possible to simulate reverse gear. This is a big, big problem as several times we use it in real word situations. Workaround: I’ve modified a normal trailer (not a wind blade tow), and I use it when I desperately need reverse gear.

Third problem, many times it would be useful to simulate problems in 3D, as sometimes the tow get stuck somewhere in a vertical transition. There is an upgraded version who allows you to works in 3 dimensions, but it doesn’t include the vehicles we use in the wind industry, so it’s not useful. The only solution is to build a 3D model of the terrain as I explain in another post and see what happen below the truck. Unfortunately it takes many hours.

Wind blades train transport

Wind blades are normally carried by ship and truck.

By the way every now and than I see cases of train transportation: for instance Siemens moved 141 set of wind turbine blades (for the amazing total of 423 blades) to Portland General Electric's Biglow Canyon Wind Farm. Siemens is also transporting towers and nacelles via rail to various project locations throughout the U.S., so it seems that sometimes this is a reasonable option.

Vestas too is experimenting train transport: in the video embedded you can see how blades are transported from the factory in Germany to the wind farm in Denmark.

And the list is not ended: Enercon took a Marco Polo grant to move his blades by train.

Marco Polo is a UE found for modal-shift or traffic avoidance projects and projects providing supporting services which enable freight to switch from road to other modes efficiently and profitably.

The Grant (€1 268 577) for the ENERCON Tri-Modal project involves using rail and ship to move components and parts from Germany to Viana do Castelo in Portugal, as well as to installation sites throughout Europe.
Discover more about Tri Modal here

Maximum wind farm internal road gradient

This is another standard problem I found in the wind farm I’m working with: mountainous areas, with difficult access and very strong inclination.

The standard maximum slope imposed by several manufacturers (for instance Repower and Gamesa) for safe transport on gravel roads is about 6% to 7%. Above 7% other technical solution may be necessary, depending on the trailer used to pull the T1 and the nacelle.

With an average quality track surface a 6x6 tractor unit can pull the nacelle approximately up to a 9%-10% slopes.

Than it is necessary to pull the truck with a bulldozer, using a steel bar or a steel cable (see pictures below). In this case the inclination was around 15%, and we used a D8R Caterpillar and a steel cable), without particular problems.

It must be noticed that in steep sections long horizontal alignment are preferable respect to closed bends.

What we normally do in extreme cases (above 15%) is to build a ramp using concrete slabs or an asphalted road: this solution is not only more expensive, but can also introduce additional problems, such as the need for environmental authorizations or from other authorities.

Here you have a 17% asphalted curve:

Concrete slabs are normally cast on site on a layer of aggregate stone, and they have dowel bars for load transfer and sealed contraction joints. An initial texturing is made with a burlap drag or a broom device, while final texturing is made with a spring steel tine.

You can find more information on the subject in the JPCP Design and Construction Guide

Jointed Plain Concrete Pavements Design Construction Guide

 

Vertical transitions curves in wind farm

The main problem with turbine tower trailers is that they are very low.

For this reason we normally use long transition curves in vertical alignment, with a parameter of the parabola (Kv) of 400 or even more. This is the best approach, as for instance the alternative of a minimum length definition of the transition is not effective (the result will depend on the difference between entry and exit slope).

If shorter, more aggressive changes in vertical alignment are made (mainly at the end of a slope, when the horizontal crane pad is reached) there is the risk of having the trailer stuck as in the pictures below.

The height below the tower is just a few centimeters, so this is one of the critical points to check in a constructive project of a wind farm.

As a bonus I post also one of the incredible manoeuvres I’ve seen in the real word, a truck almost flying in a mountainous wind farm.

Wind Turbine erection: 2 cranes working together

To lift the biggest component of the WTG, such as the tower segments or the blades, two cranes are used at the same time.

A principal crane, normally a Liebherr 1600 or a Demag CC2800, is helped by a smaller crane, often a rubber-tired rough terrain crane, for instance a Terex RT1120.

Both cranes start lifting the component at the same time - for instance in the attached pictures you can see how they hold a segment of tower.

Then, when it is a few meters above the ground, the secondary crane stop lifting the component while the principal crane continues the lift: doing this manoeuvre, the tower is rotated 90 degrees and can be positioned.

Narrow track cranes

In wind farms construction at least 2 cranes are needed: a main crane to lift component such as tower segments, blades and rotor and a smaller, auxiliary crane that help the main crane during the lift operations and can be used also with steel rebars, embedded rings or anchor cages and so on.

Basically there are 2 main types of main cranes: standard track and narrow track cranes.

Standard track cranes needs around 10 meters, depending on the model, to move on access roads. For this reason, due to the increasing number of wind farms in areas with environmental problems or in mountainous regions narrow track cranes are a winning option – they need only 6 meters, and can help save money in civil works and in dismantling, transportation and subsequent re-erection of the crane.

Terex-Demag CC 2800 is one of the available models, while an alternative is the Liebherr LR1600/2. They can move with a mounted boom, on a gradient around 10º.

When they are in an open position on the crane pad, ready for lifting, they can occupy even more space of a normal crane – they need around 14 meters.

Both cranes are designed especially to hoist 75-100 tonne gondolas up to hub heights of between 90 and 130 meters above ground level.

Nacelle Trailer (Low Loader)

Nacelle trailer (also called low loader) is one of the special vehicles currently used to carry WTG components from the factory to the wind farm.

His peculiarity is that it’s very low, only a few centimetres above the road: this is to allow transportation on public road, where bridges with a free height of 5 or less meters are common.

The weight of the nacelle is very near to the maximum that can be transported by road: in some cases, for instance with the Vestas V112, the drive train is carried separately from the rest of the nacelle and than it’s assembled on site.

There are even vehicle developed expressly for a wind turbines manufactures, such as the Nooteboom MEGA wind mill transporter developed for Vestas that allow savings as it is possible to load / unload without the use of a crane.

The average low loader has from 6 to 8 wheels, and the platform can be closed after the unload of the nacelle: fully extended the trailer is almost 30 meters, while closed is about 20 meters.