FTR is a British rapid-transit bus system, currently in operation in Leeds, Luton and Swansea.irst Group has introduced the system, using Wright StreetCar articulated buses in conjunction with infrastructure upgrades by local authorities. The vehicles have been branded as the future of travel, the operators claiming that ftr is textspeak for the word future.
Limestone is a sedimentary rock, composed mainly of skeletal fragments of marine organisms such as coral, forams and molluscs. Its major materials are the minerals calcite and aragonite, which are different crystal forms of calcium carbonate (CaCO3).
Limestone, a calcareous rock that includes dolomite and marble, is used in great quantities for fluxing in smelters and in the manufacture of lime. Of the crushed stone produced, nearly 75 percent is limestone, 8 percent is traprock, 6 percent is granite; the remainder is sandstone and miscellaneous rock types. Dimension stone for interior use must be attractive in color and texture, have reasonable strength, and resist abrasion and cleaning solutions.