Rail bed construction
Rail bed construction on the bog surface depends primarily on good drainage. Rail drains are 8m (26ft) to 10 m (33ft) apart for single lines and 15m (49ft) apart for double lines. The rail bed is formed of dry milled peat placed in position by machines to a depth of between 600mm (2ft) and 900mm (3ft), and then well rolled. Subsequently the beds of permanent lines are ballasted, preferably with 225mm (9ins), of sand or fine gravel, or crushed stone.