Kiln-drying is becoming a mandatory requirement for treated timber in Tanzania.
Timber treaters have been in talks with the Tanzania Electric Supply Company (Tanesco) in recent weeks about the viability of enforcing the kiln-drying requirement.
It is required by the timber treatment specifications published in 2017 and was expected to become obligatory for all utility poles tenders on 31 August this year.
However, after the discussions with the industry, Tanesco deferred the requirement until 31 August 2022.
The drying of timber is necessary before treatment, to free up space for the retention of CCA. If poles are air-dried, they can lose moisture only to the extent of humidity in the environment. In humid areas, this might be too high for adequate retention, making kiln-drying timber a requirement.
The Tanzanian specifications require poles to be partially air-dried and partially kiln-dried. Hans Lemm, Group CEO of Green Resources, to which the Sao Hill treatment plant in Tanzania belongs, pointed out the advantages of using kilns. While air-drying takes 3 to 4 months, the combination of air- and kiln-drying reduces this time by more than half.
“Kiln-drying allows a timber treater to become much more nimble,” he said. “You can react more quickly to the market requirements and operate with lower inventory levels.”
Hans said he understood the concerns around kiln-drying, including that the local pole business is tender-based but gives little certainty ahead of time, making timber treaters conservative about deploying capital.
“Our aim is to make the process of installing a kiln as simple and effective as possible for you.”
“However, if you want to take a lead in the industry, you have to do so by ensuring compliance with the standards, including with your equipment.
“We made the decision to invest in a kiln at the beginning of last year but there were delays in execution due to Covid-19. Ultimately, we started kiln-drying in June this year.”
Mufindi Wood Poles and Timber Plant, another Dolphin Bay client, installed kilns even before the requirement was published.
Matt Merrick, country manager for The New Forest Company in Tanzania, said that the company would comply with the statutory requirement, although he expressed concerns.
As things stand, some producers take shortcuts in the timber treatment process, producing inferior poles that have at times been accepted for tenders. Some treaters might take shortcuts with kiln-drying too − buying cheaper and ineffective kilns, for example – which would make the requirement an “exercise in paperwork”.
“The authorities will get poor quality poles unless they enforce quality treatment. It doesn’t matter what requirement you are having to meet, there will always be people who take chances, and that is the real problem,” Matt said.
The necessity of introducing kilns has been deferred again due to the high capital costs. The other aspects of the timber treatment standards in Tanzania were introduced soon after the regulations were passed four years ago.
Dolphin Bay was a member of the committee that advised Tanesco during the drafting of its specifications.
“We have engaged with kiln suppliers to investigate the best way forward, and have shared our findings with our clients,” said Dolphin Bay’s Darren Marillier. “TF Design based in Stellenbosch, Cape Town, offered the best solution, and this is the one we recommend.”
Darren acknowledged the high cost of the kilns, saying this was the reason most treaters are avoiding the prospect.
Edward Ehlers, a director of TF Design, outlined the process for installing a kiln. Substantial open space is required for loading and offloading the timber and for the kiln itself, the size of which depends on the needs of the plant, he said. The bigger the system, the more cost-effective it is.
A supply of either hot water or even better steam, usually provided by burning excess biomass, is also necessary.
TF Design can provide quality kilns within about six months of an order. The company provides a single quotation that includes all associated costs including transport, installation, and spares.
Cheaper providers can be found but typically do not provide a complete quote, and the costs quickly add up. “We also leave spares and tools on-site,” said Edward.
Dolphin Bay’s approach is that by working together, we will continue to make great strides in improving the quality of treated timber for the African market, and Dolphin Bay commits to doing its part by sharing knowledge and providing the support of its team.