... are secured by a CENTRAL bolt passing through a spacer block therefore the rail extends an equal number of timbers and CC's each side of the bolt. I will try to find pictures but this may not be untill later in the week. Wally posted: 20 May 2012 11:11 from: wally Having had a few moments this morning here are a couple of photos to add to the confusion. This installation is in the middle of a lot of plain track relaid 1949/1950 and will probably reflect the later thinking. 2374_200548_520000000.jpg This shows a pair of checks which only span 4 timbers and have a central locating bolt (only visible on the far rail and just out of shot on the near). 2374_200553_050000000.jpg Here we have a pair which spans 5 timbers with an offset retaining bolt and block and shows better the end on scarfing of two short timbers to form a longer one which was the subject of a previous discussion. This formation was made of second hand OO (97.5 lbs) rail as can be seen from the fshplate bolt holes in ...