< Div > holes in rocks to drill the possibility, is central to the construction of buildings from natural stone. With this technical ability could only stone materials in sufficient quantity mined and brought in the right form. < br/>
< Div > the first drilling rig as a machine was built in 1848. Prior to this time, drilling holes in stone was hand work.
Hand drill alone / together
< Div > after each blow, the drill was shot (about 1/8 turn). The art of hand drilling consisted of lead the drill always beautiful centrically.
were distinguished in the following hand held drill:
Churn or ball drill (hand drill without hammer, vertical holes) [ 1]
Plug drill / hammer drill / jumper drill (hand drill with hammer, holes in all directions) [ 1]
< Div > the "churn"drill (l = 7 ft / 2.1m) was raised and then dropped. In the middle of the drill rod, an additional weight was attached to the reinforcement of the shock, usually in the form of a metal ball. For deep holes (> 90cm) the churn drill was served by more than one person. For vertical holes, the Churnbohrer was the most effective drill method [ 2]
< Div > the "hammer-drill" with a simple cutter or with a star-shaped cutter (Star-drill), was used by was beaten with a hammer on the drill. In this way not only vertically but also horizontally and upwards could be drilled.
"A maennisch" drilling capacity:
2.6 ft / h. (5/8 inch diameter) = 78 cm / h [ 1].
60-80 Ponciottolöcher per day [ 1].
8 inch / h = 20 cm (rock of medium hardness) [ 3].
< div >
"Two maennisch" drilling capacity (1.5 inch diameter):
Granite: approx. 0.7 ft / h = 21 cm / h [ 1].
Basalt: approx. 1.1 ft / h = 33 cm / h [ 1].
Lime: approx. 16 ft / h = 48 cm / h [ 1].
2 feet/h = approx. 60 cm (rock of medium hardness) [ 3].
Drilling:
[ 4]
Several drills were used when drilling holes deeper than 60 cm, the diameter of which decreased with increasing depth of the hole. Such a "drill game" consisted of beginner -, middle and final drill. The art of hand drilling was always exactly axially to dan Bohrer lead [ 4].
sources:
< ol >
Handbook of rock excavation, methods and costs, Halbert powers Gillette, London, Hill Publishing Co., 1916
Brunner & lay, manufacturers of marble, stone, granite and bricklayers' tools, stone jacks, derricks, and contractors' supplies (http://quarriesandbeyond.org/articles_and_books/stone_magazine/brunne_an...)
the rock drill and civilization, Larry C. Hoffman, invention & technology magazine, vol. 15, issue 6, 1999
the construction with natural stone, Adolf Stoller, 1949