Penrhyn also had cast "chairs" of (at least two types) that were designed to be spiked down to wooden sleepers. One type consisted of the "binocular holes" the second type had a saddle for intermediate support of the round rails. There were also cast sleepers that had "binocular hole" at one end and a saddle at the other, for where there were staggered joints. The round rail was also supported intermediately by a pair of grooves in large blocks of slate. The round rails (at Penrhyn) were generally a maximum of fifteen feet, although I did see one rail nineteen feet long, now sadly buried by the new tip. In fact there were quite a number of round rails surving, only to be buried in the mid 90s.