On Sunday, June 24, 2012 3:58:05 AM UTC-4, Peter Higgs wrote:
Hi Bastoune, I would go for the petrol option as you can soon re-fill the
tank dependant upon how much use it gets.

They will tow twin seaters quite easily on tarmac.
However if the glider is leaving ruts in soft ground, they struggle a lot..
This would use a lot of battery, in an electric cart.

The usual limiting factor is wheel grip, as the wheels will spin on damp
grass, due to the light weight on the rear tyres.

Pete


Tarmac – A common but inaccurate term often referring to the paved areas of airports where aircraft park. Usually referring to the airport ramp or “apron” near the terminals, hangars or FBO’s. The vast majority of aircraft operating areas are however constructed of concrete, not “tarmac”. The Wick Airport at Wick in Caithness, Scotland is one of the few airports that still has a real tarmac runway.

In July 26, 1904, Hooley, E. Purnell received U.S. Patent 765,975 for the “Apparatus for the preparation of tar macadam” which involves involved mechanically mixing tar and aggregate (crushed stone or gravel) prior to lay-down, and then compacting the mixture with a steam roller. The tar was modified with the addition of small amounts of Portland cement, resin and pitch.

As petroleum production increased in the mid 20th century, the by-product of refining process, asphalt became available in huge quantities and largely supplanted the use of tar due to its reduced temperature sensitivity. The Macadam construction process also became quickly obsolete due to its high manual labor requirement.