RailMeasurement have developed the bi-CAT to give an instrument that measures two rails simultaneously with the same accuracy as the CAT, and which can still be transported to site, assembled and used by a single person. The bi-CAT uses the same technology as the CAT and essentially the same software to measure rail corrugation and acoustic roughness on both rails simultaneously at a comfortable walking speed of 3-4km/h (1m/s). The bi-CAT packs into the same size of plastic instrument case as a CAT, but has an additional plastic box that contains the framework. The total weight of the equipment and carrying cases is less than 28kg.
The bi-CAT can be used on flat-bottomed (Vignole), embedded or grooved rails.
We expect the main use of the bi-CAT to be for corrugation surveys and during rail reprofiling work, particularly for those clients who have to collect measurements in a short time window. The equipment was indeed developed at the request of these users.