1.5 m, 4 m

1.5 m, 6 m

1 m, 4 m

2 m, 4 m

47.5 mm, 130 mm

32.5 mm, 180 mm

65.5 mm, 210 mm

24.5 mm, 65 mm

horizontal

vertical

inclined

horizontal and inclined

non-coking bituminous coal

brown coal

peat

none of the above.

more

less

same

could be more or less depending on other factors