July 15 - Netherlands based Tower-Bridge has unveiled a brand new transport system for wind turbine tower sections.
The Tower-Bridge system works by driving the trailer inside the wind tower section. Since the system uses an ordinary extendible platform trailer, the company claims that it dramatically simplifies the transportation of tower sections.
One of Tower-Bridge's founders Norbert Schuurmans explains how the idea came about. Schuurmans was speaking to a customer who was in the process of transporting wind farm components, and was fed up with the cost of the specialised tower section transport vehicles.
"We were discussing these big 14-axle combinations that are being used not only to transport tower sections weighing 80 tonnes, but also those weighing less, at 50 tonnes," said Schuurmans.
The conclusion was that these vehicles are simply too big, over-dimensional, heavy and expensive, as well as being useless outside the continuously changing wind energy market.
Schuurmans considered suggesting a low loader, but due to the amount of beams needed, it would not be particularly cost- nor weight-efficient.
The best for cost and weight efficiency , he said, was a platform trailer but with a tower section on top, the vehicle would be too tall.
So Schuurmans' customer asked him: "Why can we not just drive the trailer through the wind tower?"
After three tests, the fourth prototype "worked like a charm", said Schuurmans. "We tested it at a wind farm in northern Holland…It only took about five minutes to drive the trailer through the tower."
The trailer is driven through the tower using a crawler, which means that no cranes are needed when loading and unloading.
Depending on the authorised axle loads, tower sections of up to 59.9 tonnes can be transported using a four-axle triple trailer, while 42.9-tonne sections can be moved using a three-axle version.
The optimum load capacity of the trailer is obtained by distributing the entire weight exactly above the kingpin and the centre of the axle bogie.
Since the trailer is extendible, once the tower section has been unloaded, the trailer can be converted back into a standard platform trailer. This means that no escort cars or permits are needed after unloading, explained Schuurmans.
Two adjustable hydraulic frames are used on either side of the tower to lift and hold the section in place. The hydraulic frames provide a horizontal pulling force of 120 tonnes on both the back and the front of the tower section. The tower can also be hydraulically lifted and lowered for easy clearance, said Schuurmans.
The system has been approved by Broshuis Holland for use on its standard trailers. Broshuis said that it has kept a close eye on the development of the Tower-Bridge system from the beginning.
Watch a video of the Tower-Bridge system in action here:
Watch Tower-Bridge's corporate video here: