English estate saves western red cedar with Wood-Mizer bandsaw and uses waste for heating
The Ragley Estate, deep in Shakespeare country in Warwickshire, England has converted 1,500 tonnes of normally wasted western red cedar into wooden products sold to builders and the general public.Such work is difficult for the main softwood sawmills which have tight diameter and taper specifications. Also this species’ bark is stringy and clogs traditional mills. The sawn red cedar is not of high value so conversion has to be economical. The estate was offered a derisory ?3.00 per tonne standing for it.
Now, through an innovative process, the estate calculates it will benefit from the equivalent of ?30-?40 per tonne standing. Furthermore, estate chief executive Alan Granger reveals an investigation into the possibility of exploiting the waste western red cedar slabs – usually consigned to landfill – to fuel boilers to heat the 17th-century hall or even to generate electricity, saving an estimated 100,000 litres of oil, worth ?35,000 pa.
A dedicated plant to generate electricity might need 100 tonnes a year of biomass like the western red cedar. As the estate generates a lot of waste wood he isn’t deterred. He continues:
"An option might be a woodchip boiler, fed by a chipper, to heat most of the house but later to drive a turbine for the electricity –– in which case the heating would become a by-product.
"That would require 1,000 tonnes a year but I’m confident about providing that too", adds Alan Granger.
This, plus the practical use of generally discarded western red cedar, would further reflect the estate’s reputation for sustainable forestry practices, typified by coppicing, thinning, clearing and natural regeneration.
The key to the western red cedar harvest lies in the use of two portable band sawmills rather than local static sawmills which are costly and lack the flexibility of the band saws. Normal handling equipment is messy, too.
When forestry manager Mike Box suggested using small narrow kerf mills the estate’s own sawmill manager expressed doubt that they would achieve a quality of cut sufficient to make the western red cedar marketable.
"However, we find the accuracy of these relatively small sawmills is excellent", says Mike Box. Additionally, the two Wood-Mizer LT40MDs are towed to ready-stacked logs of anything from 40-380 tonnes brought by a forwarder. The logs are sawn on the spot, minimising the forest floor damage usually inflicted by big sawmill lorries.
The mills’ hydraulic handling system makes the non-sawing activities, like handling the logs, quick and easy. Wide hydraulic roller toeboards compensate for log taper and make positioning easy. Via a lever, hydraulic arms load logs in seconds and self-levels them. An hydraulic log turner rotates a log or cant, again through lever co ntrol. Two-plane clamping simplifies sawing any stressed logs. Stephen Cull, who runs the older of the two LT40s, reports that they got as close as 2.5cm cuts from the bed.
"Normal handling equipment is messy", Stephen Cull claims. Harvesting western red cedar this way costs a fraction of traditional sawmilling. Combine that with the normally relinquished income from fence posts, Arris rails and gravel rails sold to builders or the general public through the estate sawmill and Ragley has come up with an attractive process.
Heating the hall with the slabs would be ‘gravy’; generating electricity too – a major development.
The 6,500 acres estate has its own large band sawmill which converts oak and other hardwoods plus some conifers from its 1,100 acres of woodland for storage and eventual finishing to estate fencing, fence panels, barn cladding, sheds, gates, picnic tables and certain specially ordered items. The sawmill also sells some wood, esp ecially chip mulch, to gardeners.
The western red cedar was grown as a ‘nursery’ crop amongst 40 acres (c15 hectares) of oak to make them grow straight and tall. Originally, greater quantities of oaks were felled as part of the war effort in the 1940s. The estate was left with a mess and at that point part of the woodland area was leased to Britain’s Forestry Commission. The commission underplanted the small amount of residual oaks with a ‘shade bear’ of western red cedar.
Now Lord Hertford, the 9th marquess, whose family have lived at Ragley since 1680, wants to restore what was once an ancient woodland site.
When his western red cedars were felled, good quality hardwoods emerged, giving a 60% cover of from 100 to 150 oaks. These will grow on for another 80 years, accompanied by natural regeneration of younger oak to emerge in something very much like its pre-WWII glory.
It will be sensibly, selectively harvested, replanted and will retain some conifers for an even canopy, with minimal gaps.
Brian Hind, UK
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England, United Kingdom
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