i did have a hole in me garden, till yesterday then a farmer filled it in fer me. and it took him about 10 mins. the hole was 20M long, about 0.5 m wide. and about 0.75m deep. so thats 20 x 0.5 x 0.75 which is 7.5m(3)
mulitiply by 6 gives yer 45 cubics meter per hour
so if yer take into account he had a bucket on the front of his tracter and a RR dint have a bucket then the RR will have a speed of 0.00 cubic meters per hour