Tuesday, 23 August 2016

Shiver Me Timbers!

The historic yeoman farmer's house Townend, in the village of Troutbeck, was recently extensively restored after wet rot was discovered in the structural timbers.
Under instruction from Stephen Haigh, Buildings Archaeologist, we cut out sections from the old timber so that a dendrochronologist could analyse them at a later date.
Simply put, Dendrochronology is the scientific method of dating wood through the analysis of the patterns of tree rings aka growth rings.

Hopefully it can be determined in which year the timber was felled... thus giving a valuable insight into the history of this wonderful house.

In the images above Stephen Haigh has chalked the sections of wood to be cut out for the dendrochronologist to examine.
The timbers removed from Townend have been labelled  to indicate in which part of the house they were used for during its construction.
A cut through a comparatively sound section of wood...
...in contrast this one is rotten for much of its length!
'Chain Saw Carnage'!
Stephen Haigh's liaison with the dendrochronologist has resulted in these samples being cut from the timber. Meticulously labelled, they are to be sent away for analysis.

This was one of the more unusual jobs we have been involved with!

Any updates will appear here.

Tuesday, 16 August 2016

New Bench for Holme Crag, Jenkyn's Field.

 National Trust Jenkyn's Field provides a rare public access point to Windermere's North Eastern shore. It's entire Western flank is bounded by the lake.
 In stark contrast the busy A591 runs alongside the full length of its Eastern side.
An image of Jenkyn's Field shore as seen from the lake in Winter.
Above can be seen the record breaking conifers of Skelghyll Woods.
Many years ago there used to be a bench on Holme Crag, a rocky outcrop  of Jenkyn's Field,  jutting into the north east side of  Windermere near to Waterhead.

Holme Crag as seen from the lake.

Thanks to a National Trust supporter, who chose to celebrate the birth of his grandson with a generous donation to our work in this area, we were able to commission a local blacksmith to fabricate a new bench.
To give the new bench a firm foundation an oak sleeper was cut in half. Two parallel trenches were dug, at a set distance, within which the sleepers were placed...see below.
A certain amount of landscaping was needed to get the bench as level as possible on its newly positioned supports. 
The base of the bench was drilled back at St. Catherine's to allow it to be firmly attached to the two sections of sleepers... using coach screws.
Approaching the bench (after a brief steep walk) you'll be rewarded with...
...a splendid view of the North West shore of Windermere... somewhere to sit and enjoy it... and forget about the busy A591 so close and yet, seemingly, so far away.
Subsequently the area around the bench has had lake-shore gravel spread around its base.

Wednesday, 3 August 2016

Summer Branch Drop.

Last week a loud cracking noise disturbed the peace and quiet of a hot, still afternoon at St. Catherine's. Within seconds a large oak branch crashed to the ground, narrowly missing the Spirit of Place sculpture that stands at the entrance.
This occurrence had all the hallmarks of Summer Branch Drop (SBD). Once considered a rare event, anecdotal evidence now suggests, this may be more common than was at first thought... Mature or veteran oak trees, along with beech and horse chestnut, are particularly prone to shedding branches during prolonged heat waves or in calm weather, after heavy Summer rainfall.

Why, on windless hot Summer days, do branches showing no apparent defects suddenly and mysteriously crash to the ground?  One theory is that when the demands for transpiration (water evaporation from leaves) overwhelms the tree's vascular system... the tree responds by shedding branches. Other theories include tissue shrinkage, internal cracks, difficult to detect rot, and/or ethylene gas being released inside the branch....but there are no definite answers. Consistent warning signs have not yet been established or confirmed.
Above is an image of where the branch split. The wood looks perfectly sound, and even with the most rigorous  inspection, it would be nigh on impossible to predict, prior to the branch being aborted, that it would fail.
 Liam, Woodland Ranger, is seen here cutting up the branch.

Waste not. Want not. More firewood for the Footprint log burner!
The brash will provide excellent habitat for wildlife. Hopefully it will provide cover for hedgehogs... numbers of which are, sadly, in steep decline
This veteran oak at National Trust owned Jenkins Field is adjacent to the A591 near Ambleside. A very busy road and the pavement is used by many walkers.
In successive years this tree has shed branches in late Summer. The evidence of one branch failure can be seen in the image above. The road was blocked on this occasion until the branch was cut up and removed; the police directed traffic while this was going on! Mercifully no one was underneath the tree when the apparently healthy branches were discarded.
The concern that the tree might abort yet more branches in the future prompted the National Trust, at considerable expense, to reduce the crown of the tree to ensure the safety of walkers and motorists in its vicinity. Close examination showed potential weaknesses in some branches so more pruning was done than was at first envisaged. In the image above a split branch and a cut branch next to it can be seen. 

Overall the risks associated with SBD are small and even in hindsight the cause is usually a matter of speculation or an educated guess!

The National Trust carry out regular and thorough tree inspections. Identifiable problems, or quantifiable risks are dealt with as soon as possible.

Since the summer branch drop at St Catherine's we have had a similar problem here at Aira Force. during the heavy rain and wind on Wednesday night, a huge limb was spotted (on an early morning litter pick) to have fallen off an Oak tree.
Luckily there was no damage to the path, it was however extremely dangerous for members of the public.
Similar to the limb at St Catherine's there were no obvious signs that this would happen
Our forestry team were quickly on the scene to clear the tree and prevent any further damage.