Standard Ffestiniog Railway Long slab waggon. These waggons (The Ffestiniog Railway always used 2 'g's) were purpose built for carrying large blocks of slate from quarries to various mills etc. in the surrounding area.
Thanks to Paul Hobbs for his mesh library elements, some of which have been used in the model and for the great tutorials, which helped me get this model working.
Other peices of FR stock by kevmt can be found on the Ffestiniog page at http://www.trainzone.co.nz/ffestiniog.htm.