When it comes to aerodynamics, size does matter. For planes, bigger wings create more lift, and for wind turbines, bigger blades can be used to generate more power. As wind turbines have grown ever larger over the years, this has posed an issue around transporting these giant blades, particularly through the confines of small towns and tight mountain roads. One transport company has found a solution to that problem in the form of a very specialized vehicle.

The problem with transporting wind turbine blades is that they are long, continuous pieces of great length. Modern blades can be up to around 350 feet long in the case of the 10-megawatt class of turbines. Often, getting them to an installation site requires transit through towns, which can pose huge problems. Normally hauled by semi-trucks with a dolly at the rear, it can be impossible to get a wind turbine blade through a roundabout or a tight corner in such situations. In those cases, cranes must be used to lift the blade through, before reloading the truck and continuing the journey.

The transport industry built a new class of vehicle to solve this problem–the self-propelled rotor blade adapter. The Scheuerle Rotor Blade Adapter G4 is the type seen here, built by German industrial giant Transporter Industry International, or TII. Fundamentally, it looks like a giant yellow trailer with no attached semi truck. It features a single cantilever-style mount for a large turbine blade.

The end of the turbine blade is left unsupported, with no dolly at the rear. The real magic, though, is in the fact that the mount itself can pivot. This allows the blade to be raised up at an angle when required. It’s a crucial feature that makes all the difference, allowing the vehicle to get a turbine blade around a corner without clipping street signs or knocking off chimneys.

If the basic concept looks familiar, it’s essentially a self-propelled modular transporter, or SPMT, with a wind turbine mount on the back. SPMTs are used for all kinds of heavy, slow-speed hauling jobs, like moving parts of ships, oils rigs, or even shifting entire buildings. The vehicle runs on a 300 horsepower diesel engine, though it doesn’t directly drive the wheels. Instead, hydraulic motors are used to drive the wheels on a couple of the axles, providing fine control. Each axle can also be steered on its own pivot, and can be raised or lowered to keep the vehicle flat even on very uneven terrain.

The vehicle is driven by remote control by an operator walking along with the vehicle. Indeed, this isn’t a limitation, as it’s not designed to go much faster than this anyway. When you’re trying not to poke a hole through somebody’s house with a giant turbine blade, it’s pretty typical to want to take your time, anyway. You’d never use one of these for long-distance transit, of course; it’s for use in tight situations where just hauling a blade on a trailer simply won’t do.

It’s capable of tilting a wind turbine blade up to an angle as steep as 60 degrees. That’s helpful for navigating hairpin turns that would otherwise be impossible with a long blade. It’s particularly relevant, given that wind turbines are often installed in mountain areas with winding roads that pose great challenges to navigate with such large, unwiedly cargo.

With a giant turbine blade raised so high up in the air, there can be some tipping concerns, especially on sloped roads. To manage this, the platform’s tilt sensors trigger a warning vibration on the remote control if the platform is at risk of tipping. The operator can then use the hydraulics to extend the wheels on one side to level the platform on uneven terrain.  A wind speed sensor can also be fitted to the blade to ensure it’s not at risk of getting blown over. If speeds are excessive, the operator is warned so they can either lower the blade down, or rotate it so it presents a slimmer profile to the wind.

Saving time, effort, and money is the whole point of this design. It’s intended to be a quicker, safer, and easier way to get a turbine blade through a restrictive physical environment. To further aid in productivity for delivery crews, there are some other nifty design features, too. There is a hydraulic-locking quick-release fitting for turbine blades that can be used to speed up the loading and unloading process. It consists of a steel frame that is bolted to the blades ahead of time, and mounts to the blade carrier via pins. This allows a bunch of blades to be fitted up with the adapters in advance, so the transport crew can simply load and unload them in a hurry. A further boon is that when the blade carrier has dropped off a blade, its drive axles can be raised so it can be hauled back to pick up another with a semi-truck. This is much faster than driving the machine back at its regular walking pace.

If you live in a hilly or high-wind area, you just might see machines like these crawling around your town sometime in the future. They’re set to be a crucial backbone of the wind energy industry as it continues to build larger, more powerful turbines.