9: De Road roller.

A steamengine that has been used widely also in the Netherlands is the roadroller. Many people will remember this engine; they have operated up till 1967. In the sixties you could see them regularly busy steaming at roadwork activities.
It is remarkable how fast and smooth changes took place in home and at the street. I can remember that the roller was like a magnet, pulling me towards the hissing and the clouds of steam and smell of coal after leaving school towards the highway not far away where the steamrollers were at work.
I was unaware of the changes in the street from steamrollers to diesel driven rollers, it went smooth and “silent” but suddenly, steam was gone. And, these new engines looked also attractive, so the old situation faded away in my memory. And when you realise that, it is often too late!
How many people do still remember the steamdriven piling engines, and when you mention a roller, very often is still used the old word steamroller.
The steamroller can be seen as a traction engine which has very broad wheels, designed when road development programs asked for a better quality of roads, more compact and smoother to drive on.
Several firms who constructed traction engines started to build road rollers; the biggest problem they had was how to connect the front roll to the engine. Because the roll could only be connected and supported at its outer ends and had also a steering function, a special fork construction had to be developed. The steering pen on top of the fork formed the connection to the engine. This construction increased the height of the engine and asked for modifications of the smokebox. Trials to replace the traditional front wheels of a steamtractor by broad wheels, like at the rear end, were no success.
To use the engine as an economical “multipurpose” engine, constructions were designed enabling to use a roll but also normal wheels so the engine could be used as a tractor, the convertible engine.
As extra the roller could be equipped with a scarifier, a set of heavy pens mounted behind the rearwheel(s). A scarifier worked like a plough, breaking open the surface of the road and when present, also the old asphalt layer. For larger rollers also a rotating scarifier was designed. These scarifiers were hanging behind the roller like a small waggon. The driving force was coming from the roller via a belt over the flywheel.
With the introduction of the steamroller the quality of the roads improved remarkably. In the old days the roads where made of gravel, sand and rubbish. Rolling them with the steamroller made the road more compact. The invention of asphalt gave a big improvement of the roads.
Modern roads are still covered with asphalt (sometimes also called macadam roads). The construction principle is still the same as in the old steamdays: rolling slowly and with a heavy weight to compress the asphalt mass.
Steamrollers were not classified by the power the could develop (hp), but by weight: a light 5 Tons roller or eg a heavy 15 Tons roller.