Masonry Magazine June 1963 Page. 13
Quarrying
Limestone
This is
Indiana Limestone
One of America's most famous building materials is Indiana Limestone. It possesses unequalled qualities and enjoys many desireable physical characteristics which make it a material in great demand by the nation's architetcts.
In this feature section of MASONRY we will try to acquaint our readers with its quarrying, physical characteristics, as well as it's many new uses.
From time to time other Masonry Industries will be featured in the pages of MASONRY.
The romantic history of Indiana Limestone dates back to the opening of the Indiana "discovery" quarry in 1827. A 15 by 40 mile area in southern Indiana, mostly in Lawrence and Monroe counties, these two counties are the only place in America where oolitic limestone is exposed and accounts for 78% of U.S. block and dressed limestone, according to the U.S. Government.
Though stone from Indiana's quarries has been used in many of the nation's architectural masterpieces, few persons realize the gigantic operations which must be carried on in the quarries before the stone ever becomes marketable.
Before the salable Salem limestone is reached, an overburden of clay, sand and stone must be removed by power shovel and bulldozer, and in infrequent cases, by blasting. After the overburden of earth is removed, crews of veteran quarrymen, many of them third and fourth generation stone men whose families have never known any other kind of work, move in to begin their operations of removing the 'first floor."
Today steel and machines have taken the place of the slow and tedious operations of quarrying by large crews of men with ropes and wooden derricks of the early days.
Small machines, either steam or electrically powered, begin operating with their steel chisels. These channeling machines inch back and forth on portable tracks, slowly chiseling out the first floor of a limestone quarry.
A floor is normally 10 to 12 feet deep, which is the length of the steel tools used on the channeling machines. Quarries can have many floors, but the choice Salem limestone is usually only 40 to 50 feet deep, which means that the average quarry has about four floors.
After the first large channel cut, which may cover an area of stone 800 feet by 200 feet, smaller cuts are made to divide the stone into strips two to three feet wide. One key block row is removed to facilitiate removal of the limestone in hugh masses measuring about three feet wide, 10 to 12 feet deep, and 30 to 60 feet in length. A block of such stone, 60 feet long, weighs 250 tons.
These hugh blocks are then cut into 'mill block' or dimension stone sizes for convenient transportation and handling in the cutting and fabricating plants. A dimension stone usually weighs from five to 25 tons and is about three feet thick, eight feet deep, and 12 feet long. Huge steel derricks lift these blocks from the quarry to trucks or railroad flat cars for transportation to the cutting yards and the mills.