4 inches wide, and 114 inch thick, with three holes drilled in them, by means of which they were fastened to oak rails, these latter being in turn laid upon sleepers.
In 1776 we find in use, at the Sheffield Colliery, cast-iron rails of an angular section (Fig. 1), laid upon wooden sleepers, and which required no flanges to the wheels. Tramways constructed in this manner exist, and are in use in some parts of the country at the present time.
![Sheffield Colliery Tramway of 1776](http://upload.wikimedia.org/wikipedia/commons/thumb/6/67/Sheffield_Colliery_Tramway_of_1776.png/500px-Sheffield_Colliery_Tramway_of_1776.png)
Fig. 1.
Sheffield Colliery Tramway of 1776.
In 1789 a railroad or tramway was constructed at Loughborough, having cast-iron "fish-bellied" rails, from three to four feet in length, resting on stone blocks instead of wooden sleepers, and requiring flanged wheels (Fig. 2).
The first malleable iron rail was patented by J. Birkenshaw, in 1820, and this form of permanent way,