means for positioning the brake block so that the first measuring point on the brake block is aligned with the first support surface and {HEAD ~ the second measuring point} on the block is aligned with {TAIL ~ the second support surface} 
means for positioning the brake block so that the first measuring point on the brake block is aligned with the first support surface and { HEAD ~ the second measuring point } on the block is aligned with { TAIL ~ the second support surface }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD HEAD HEAD HEAD OTH OTH OTH REL REL REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL