Quarter sawing

Quarter sawing is a way of converting a tree so that all the planks have all the annular rings at 90 degrees to the widest face and there are many benefits in doing this. This technique is called quarter sawing because all methods involve first cutting the tree from the round into 4 quarters.

The main benefit is that a much more even rate of moisture extraction is possible as all Oak is ring porous, Black Oak particularly. When an Oak plank dries the annular rings always want to straighten out, this would result in cupping if the annular rings were parallel to the widest face. When drying a quarter sawn Black Oak plank it will just contract in its width, (by up to 1/3rd). Similarly when a fully dried out a quarter sawn plank is subjected to significant changes in temperature and relative humidity it will only expand and contract in its width without a lot of distortion. In short a quarter sawn plank of Oak is more stable.

When quarter sawn, Oak displays a section through a medullary vessel across its width. We call this medullary ray figure and this is particularly beautiful in Black Oak as the medullary vessel is very wide. Medullary vessels carry nutrients from the sap to parts throughout the diameter of the tree.

The Jubilee Oak has been milled so all the planks are sequential and they are either rift or quarter sawn.

Hamish Low

Digging up the past

For 25 years I have been trying to evaluate the viability of Black Oaks either as they are being dug up from the peat or immediately after. The very large ones are usualy broken up into random size pieces due to exposure before they were preserved. The longest one I have been able to piece together had an astonishing branchless length of 115 ft. However when these very large trees are trimmed to manageable lengths of no more than 12 ft it is possible to see the growing taper and so establish which way up they were. The stagering fact about The Jubilee Oak is that even though it was 44ft long we had no idea which way up it was. This could only mean that what we were looking at was only a small section of a much, much larger tree.

When faced with these huge trees emerging from the peat it always makes me wonder what it must have been like for nomadic family groups to wander through forests of such vast trees. The Jubilee Oak is giant amongst giants and so it was an opportunity to try and share this tantalising glimpse into the atmosphere of the ancient past. This is why we didn’t cut it into more sensible and manageable lengths.

Hamish Low