To enable her to probe the depths, all but two of "Challenger's" guns had been removed and her spars reduced to make more space available. Laboratories, extra cabins and a special dredging platform were installed. She was loaded with specimen jars, alcohol for preservation of samples, microscopes and chemical apparatus, trawls and dredges, thermometers and water sampling bottles, sounding leads and devices to collect sediment from the sea bed and great lengths of rope with which to suspend the equipment into the ocean depths. In all she was supplied with 181 miles (291 km) of Italian hemp for sounding, trawling and dredging.