Sawmill
Click to download this resource as a Word Document
Site of Former Sawmill
During the Second World War there was a large demand for timber and a temporary sawmill was set up in Chopwell Wood. Having a sawmill in the wood speeded up the processing of timber, once trees had been felled. The sawmill was operated by foresters who were exempted from military service, and they were helped by women from the Women’s Land Army, who were known as “Timber Jills”.
Activity 1
Look at the artist’s impression of what the sawmill looked like.
What can you see going on in the picture?
Answers - A tractor dragging logs
A steam engine providing power to the sawmill
Foresters bringing in a log ready to be sawn
Foresters cutting a log in half using a circular saw
Timber Jills stacking the sawn pieces of wood
Activity 2
Look at the pictures of the piles of logs for a few seconds.
Estimate how many logs you can see.
Check your answer by counting carefully.
 |
 |
 |
Log stack 1 photograph courtesy Paul Fountain |
||
Answers
Log stack 1
By counting : There are about 90 logs. It is difficult to be precise.
Estimating using triangular numbers.
Assume a bottom row of 18 logs. There would be 171 logs in a triangle. 
However, the shape is more like a trapezium. Assume 12 logs in the bottom row of the “missing” triangle. There would be 78 logs in this triangle. 
.
171-78 = 93
Log stack 2
By counting there are about 90 logs. Again it is difficult to be precise.
Estimating using rectangles.
The shape is roughly a trapezium. Assume there are 22 logs in the bottom row.
The shape is roughly two triangles at the ends, 6 logs long, and a middle rectangle 10 logs long. The stack is about 5 logs high.
Putting the two triangles together as a rectangle gives 
logs
and the middle rectangle 
logs.
This gives an estimate of 80 logs.
This looks to be an underestimate but there is a lot of variation in both the size of the logs and the way in which they are stacked.
Log stack 3
By counting there are 60 logs on the back of the trailer.
The logs in the middle of the trailer cannot all be seen, but the stack isn’t as high.
Assuming the height is about two thirds of the back trailer, estimates say 40 logs here. .
The logs at the front of the lorry also cannot all be seen, but the stack is higher than the one at the back, so estimate about 80 logs here.
There are 6 logs in the crane.
Lying on the ground facing the camera there are 9, or possibly 10 logs, with another 4 or 5 lying on top of them. .
It is not possible to count the number of logs in the stack by the roadside.
If we assume the stack is triangular and is 10 logs high then we could estimate 55 logs, as 55 is the tenth triangular number. However, we can’t tell how many logs there are on the bottom row, nor what shape the stack really approximates to.
Extra resources
Stacking Logs in Rectangular Shapes
Stacking Logs in Triangular Shapes
There are extra resources on logs stacked in triangular and rectangular shapes assuming all the logs have identical circular cross sections.
This offers a chance to investigate triangular numbers and other number patterns in the context of stacking logs in piles.
Go Back
