The steepness of vineyards is given in percentages or degrees. However, the values given in many sources are often incorrect due to misstatement or confusion of percent and degree. At 45°, this is the equivalent of 100%; 45%, on the other hand, is only 24°. The not possible 100° (overhang) would result in 567% purely mathematically. A slope of 90° corresponds to a vertical wall. The real maximum values of vineyards are about 75° (373%). In steep-slope viticulture on extremely steep slopes, conventional mechanical cultivation is often not possible, but only laborious manual work with the help of special equipment. The vineyards there are usually laid out in terraces with retaining walls and stairs. Rope hoists or special caterpillar vehicles have to be used for the largely manual vineyard maintenance. Traditional training systems such as single-pole training (Moselpfahlerziehung) are often common on such vineyards. In exposed areas, the spraying of pesticides is done with the use of helicopters, as well as the transport of materials, people and grapes during the harvest via monorack railways.