Harvesting is largely clearfelling of unthinned crops because of the high proportion of high wind hazard class (unstable) crops. Thinning operations are confined to amenity and recreation areas, areas around communities and areas sheltered from strong winds, in total they amount to 35000 cubic metres (m3) per annum. Total current felling programmes amount to 540000 m3 annually, a figure expected to reduce in 5 years time reflecting past planting programmes.
Crop rotation lengths are dictated by exposure and soil conditions, with most crops being felled when they are between 17 and 25 metres in height. Timing of felling of a particular compartment is also related to the age and height of adjoining compartments in order to achieve the objective of creating the diverse age structure which is central to the restructuring process. In order to achieve this, rotations have to be truncated because the opportunities for extending rotations to achieve the diversity of age are limited.
Around 50% of the timber is sold standing and harvested by the purchaser who may be a merchant or a wood processor/sawmill. The remaining 50% of the programme is harvested by the Forestry Commission using contractors or direct employees.
Currently we are harvesting the remainder of our first rotation crops which are yielding about 60% logs and 40% small roundwood. Most of these crops are now very liable to windblow, the effects of which can be seen on the edges of many stands.
Major SRW markets are the pulp mill at Workington, Cumbria making cartonboard, and Egger at Hexham, Northumberland making chipboard products. We also supply SEMCORP in Teeside where the wood is used at the power station.
Sawlogs are processed at a number of sawmills in southern Scotland and Northern England, with a small proportion milled as far away as Wales. Logs are graded into those suitable for the construction (carcassing) industry and those for smaller sawmills which cut for the pallet and fencing markets . Total income amounts to some £12.0 million per year.
Methods of sale
Marketing of Timber is the responsibility of the National Office in Bristol and is presently sold mainly using electronic tenders throughout the year. These events are used to sell both sawlogs and standing timber.
The bulk of the SRW produced by the Forestry Commission is sold on long or medium term national contracts negotiated with the large pulp and chipboard mills. Sawlog and Standing Sale contracts fall into one of two categories, long term contracts which run for 5-10 years and open market contracts which run from 6-12 months.
Much of the log is sold by weight with the better log material being sold by volume. Standing sales are predominately weight sales but volume sales are used depending on crop and market conditions.
The mean tree size of harvested crops is currently 0.35m3 although a full range of tree sizes with averages from 0.05 - 0.8m3 is cut. Around 90% of operations are fully mechanised with only the roughest trees and those on difficult ground requiring felling and de-limbing by chainsaw.
Thinnings use a mix of methods from machine and chainsaw felling with extraction by horse, forwarder, skidder or cable crane.
Clearfell operations are mainly mechanised felling with small areas of chainsaw, extraction by forwarder with skidder or cable crane on more difficult terrain e.g. steep slopes or wet ground.
On any day in Kielder some 20 - 30 mechanised units will be working felling and extracting timber, allowing over 1750 metric tonnes to leave the forest for the mills every day of the year.
Harvesting machines are mainly Scandinavian purpose built machines costing between £180-300,000 depending on type and function. These machines use the latest technology and produce 12-20 tonnes per hour.
Responsible for handling 50% of FC work and most of that for purchasers of standing timber they may be employed on a short or medium term basis. 80% of the FC work is on a medium term basis.
Haulage is carried out entirely by contractors or the purchaser. An agreement exists between the Forestry Commission and the local Highways Authority which limits the use of heavy timber traffic to certain agreed public roads. This has resulted in a slight increase in the FC internal road network but has allowed the Highways Authority to concentrate its strengthening work on strategic haulage routes.