Hello ladies and gents! I have a question regarding track. Recently on my patch there have been several track renewals over the past few months. The whole lot has been ripped up and replaced in sections. Today whilst driving after another weekend of engineering works I have noticed the addition of what appears to be some sort of fasteners on the sleepers between the running rails. Can anyone tell me what they are? They were not present on the old sleepers or when the track was first laid. They run the entire lengh of the newly laid track which is about a mile or so. (See attacted picture)