Cinder Runway?

[Spandau]

In some of the older books written by guys like Ernest K Gann, etc I've read the occasional reference to a "cinder" runway. Anybody know exactly what that would be? Concrete like, as in "cinder block", or more like a gravel runway, or...?

[Hockaloogie]

Like gravel. Cinders were the remnants of coal combustion. When I was a kid there was a factory nearby that had a cinder parking lot. The stuff is like gravel.

[Spandau]

Ok - that makes sense because I'd heard of cinder runways being graded periodically. Thanks for the help.

[pelmet]

A couple of mentions about it here.

Sounds like a hard surface but not sure...

https://books.google.co.uk/books?id=Fvz ... ay&f=false

[Meatservo]

Otherwise known as "clinker". Like Mr. hock a loogie said, it's the slag from coal. Enourmous quantities of it are produced by steel plants, power stations, etc. It's part ash and vitrified minerals. It's extremely hard and sharp, and packs down nicely the way mine-crush granite does. However, it's also very sharp and I imagine it would be murder on the tyres. The dust, I'm speculating, would be as nice for compressor blades as volcanic ash.