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Examination of timbers from the Mary Rose in storage
1988 - IRG/WP 4149
Timbers from the Tudor ship, Mary Rose, have been examined for the presence of fungal fruiting structures. Wood specimens were also examined for the presence of microbial decay patterns using light and scanning electron microscopy. Structural timbers were surveyed using the Pilodyn for an overall picture of the extent of decay. Mary Rose timbers were predominantly inhabited by marine fungi. Fourteen species were found fruiting on the surface but fungal decay was localized. Bacterial erosion and tunnelling of the wood cell wall were observed, but were rare. The Pilodyn has shown that decay in timbers exists in isolated pockets. The storage site has proved to be efficient in minimizing further microbial decay, while maintaining the waterlogged state of timbers.
Bacteria and wood. A review of the literature relating to the presence, action and interaction of bacteria in wood
1971 - IRG/WP 101
S E Rossell, E G M Abbot, J F Levy
Importance of bacteria in the deterioration of archaeological woods
1995 - IRG/WP 95-10122
An electron microscopic study of archaeological woods from different sites and of different ages revealed that the woods had been attacked by erosion bacteria, tunnelling bacteria and soft rot fungi. Bacterial erosion appeared to be most widespread, and was present independently as well as together with tunnelling and soft rot attacks. Thus, in many instances bacterial erosion was the only type of microbial attack present. This work recognizes the important role bacteria play generally, and erosion bacteria particularly, in the deterioration of waterlogged archaeological woods.
Yoon Soo Kim, A P Singh, T Nilsson
Ultrastructural aspects of bacterial attacks on an archaeological wood
1993 - IRG/WP 93-10007
Transmission electron microscopy of wood from a Chinese ship submerged in the mud for over 900 years showed bacteria to be the main factor for its deterioration. The micromorphology of degraded wood cell walls was similar to that observed during the attacks of wood by erosion bacteria. Other bacterial forms, previously considered lo be scavenging bacteria, were also abundant in degraded areas of the wall. The observations on the breakdown of the waterlogged archaeological wood are discussed in context with the available information on bacterial degradation of wood under near-anaerobic conditions.
Yoon Soo Kim, A P Singh
Effects of boron treatments on partially decayed oak and pitch pine heartwood
1996 - IRG/WP 96-30106
This paper reports results of borate based preservative treatment and leaching experiments on partially decayed oak and pitch pine heartwood. Previous experiments have shown little damage is caused to sound timber of these types when treated with Polybor and Boracol 20 preservatives. This experiment was carried out to assess the suitability of selected borate based preservatives for use in historical ships' timbers and therefore the physical effects of these preservatives on such timber was investigated. The results indicate that weight losses incurred due to treatment with Polybor or Boracol 20 are no more damaging than those incurred by treatment with water. Weight changes were more apparent in decayed timber than in sound timber with greater uptakes in non-leached samples and greater weight losses in leached samples. However, comparable weight changes were recorded between water treated samples and preservative treated samples. Dimensional changes were minimal in most cases, the greatest found in non-leached Boracol 20 samples as expected. These results indicate that treatment with these preservatives is suitable for partially decayed oak and pitch pine heartwood.
S McCutcheon, G M Smith, J W Palfreyman, P Durrant
Microbial decay of an archaeological wood
1994 - IRG/WP 94-10053
A light and transmission electron microscopic investigation of an archaeological wood was undertaken to determine the cause of its deterioration. The wood came from a bulwark constructed in early 1100 in the lake Tingstäde Träsk on the island Gotland in Sweden. The samples of the wood, which was identified as Pinus sylvestris, were taken from a depth of 0.85 m below the bottom level. The wood was found to be heavily deteriorated, and from the micromorphology of decay observed under light and transmission electron microscopes it was concluded that the wood had been largely attacked by erosion bacteria. The degradation of wood components was quite variable, some cell structures/types showing greater resistance than others. The S2 wall layer of axial tracheids, which formed the bulk of the wood, was degraded most. In comparison, ray tracheids appeared completely resistant. Other cell structures/types, such as pit borders of axial tracheids and ray parenchyma cells, displayed features that were intermediate between the extremes noted above. These features are discussed in the light of available information on bacterial erosion of wood cell walls and on chemical composition of these cell structures/types in pine wood.
A P Singh, T Nilsson, G F Daniel
Wharf-borer a threat to stored archaeological timbers
1992 - IRG/WP 92-1560
Increased interest in marine archaeology has occured in recent years. Stored waterlogged archaeological timbers have been shown to be degraded by physical and microbial agents. In recent years a new threat has been highlighted, namely the wharf-borer Nacerdes melanura (L.). The objective of this paper is to outline studies of the morphology, biology, life-history and carbohydrate digestion by this beetle. These studies will allow improved preventative measures to be employed by conservators and archaeologists in the passive holding of archaeological timbers.
A J Pitman, E B G Jones, A M Jones, M Rule
Study of the degradation caused by micro-organisms in Pinus sp. waterlogged wood
1989 - IRG/WP 1411
So far, the different Centers are trying the restoration and the conservation of wood structures, coming from subaquatic archeological deposits, with interest from the historic - artistic point of view. The main objective of this paper has been the determination of the decay level of Pinus sp. wood coming from a roman ship (approximately 2000 years old), where we have analyzed their physical properties, their chemical composition and the marine microorganisms (microfungi and bacteria) within.
M T De Troya, M C Escorial, J Garcia, A Cabanas
Ultrastructure of Prumnopitys ferruginea wood from a buried forest in New Zealand
1991 - IRG/WP 1489
The buried wood of Prumnopitys ferruginea, a New Zealand native tree, was examined by scanning and transmission electron microscopy to investigate the extent to which the wood had deteriorated and the cause of its deterioration. Examinations showed that some deterioration of wood had occurred. Microscopy revealed a decay pattern similar to that produced by cavitation bacteria. Lenticular cavities were seen in the S2 layer of tracheid walls oriented diagonally to the length of tracheids. Large areas of the affected S2 wall had a dense, homogeneous appearance. These differed from sound areas of the S2 wall which were much lighter. Some areas of the homogeneous wall contained dense granules. The impression obtained from high resolution images in the TEM was that the granulation of the homogeneous wall preceded clearing of this wall. We assume that cavities formed in these clearing zones.
A P Singh, T Nilsson, G F Daniel
Information from the COIPM wood group. (With Appendix: Préserver les matériaux en milieu marin sauvegarder l'environment marin telles sont la vocation et la mission du C.O.I.P.M.)
1989 - IRG/WP 4156
During the last COIPM Meeting, up to date information on cooperative work to test the resistance of plastic wrapping for pilings were submitted and discussed. In 1986 untreated wood samples wrapped with shrinkable polyolefin sleeves were submerged in 9 stations, situated in temperate and tropical waters. After 1 or 2 years of immersion the samples showed no sign of penetration by marine borers and the surface of wraps was intact. The samples showed moderate to extensive fouling on their surface The control samples in Mediterranean Sea were destroyed within a year. The degree of attack by marine borers and the characteristics of the sites (temperature, salinity, pH) are reported in Tab.1. A study on the biodegradation of waterlogged archeological woods from a 2,500 year old shipwrech was presented. The shipwrech, probably a Greek merchant boat, was detected many years ago near the Isola del Giglio in Tyrrhenian Sea and partly brouht up. The wood samples recovered belong to the ship-planking and to some tools and instrumets, even musical instruments such as flutes. The woods show a severe marine borer attack. At the moment the wood specimens are preserved in water with a fungicide solution. The various decay patterns of the cell wall were illustrated by photos and dias. This study is carried out by Wood Institute of Florence in collaboration with the Archaeological Museum and includes the identification of wood species (three sofwoods and ten hardwoods), their biodegradation and the conservation treatments. A classification on the wood natural resistance against marine borers in Mediterranean Sea and in temperate waters was discussed. This classification was prepared by the Chairman for the Working Group 2 "Natural durability" of CEN/TC 38.
Micromorphological and chemical changes of archaeological woods from wrecked ship's timbers
1987 - IRG/WP 4136
Micromorphological and chemical alterations of sea-waterlogged woods obtained from the ship-wrecked materials which had been submerged in Yellow Sea for over 700 years were investigated. The woods were deteriorated in varying degrees by marine organisms depending on species and parts of the woods. Under the light and scanning electron microscope the morphological characteristics of deteriorated woods were granular in appearance, erosion troughs in S3, separation of secondary wall from compound middle lamella and hole formation. Destruction occurred preferentially in S2 layer, followed S3 and middle lamella which was hardly deteriorated. Chemical analysis showed that lignin was more and holocellulose was less in the degraded than in the normal wood. The ratio of extracts by alkaline compared to hotwater and that of holocellulose were also markedly lower. These results suggest that microorganisms decomposing carbohydrates were the primary agents causing deterioration of sea-waterlogged woods.
Y S Kim
Preservation of basidiomycete hyphae in ancient waterlogged wood materials
1992 - IRG/WP 92-1536
Studies on waterlogged archaeological wood show that basidiomycete hyphae may persist as long as 800 years. In two pine wood samples with Phellinus pini heartrot, one from the foremast of the ship Vasa and the other from a bulwark constructed in the first part of the 12th century, numerous resin covered hyphae were observed. Hyphae with clamp connections that were associated with brown and white rot decay were observed in other samples from the bulwark.
T Nilsson, G F Daniel
Effects of boron formulation on specific timber types used in ships of historical importance
1991 - IRG/WP 3676
This paper reports results of preservative treatment and leaching experiments, using borax, polybor and boracol 20, on small wood blocks of English oak and American pitch pine heartwood. Earlier experiments on the performance of various biocides as possible additives to bilgewater to prevent fungal decay of shipping timbers had suggested that some formulations of boron might be associated with physical changes to specific types of timber. Since samples of oak and pitch pine were to be supplied for remedial work on the historic ship RRS Discovery it became important to investigate more critically the effects of boron on such timbers. Variable factors investigated in this study included temperature, sample type, soaking time in preservative and time of leaching. Weight changes and dimensional changes were measured. Preliminary results indicate that there was little effect, at 10°C, on block weight or dimension. Some changes were found at 45°C indicating that the results obtained in earlier experiments may be unrepresentative of those which might be obtained when the biocide is used under service conditions.
B King, G M Smith, J W Palfreyman, S McCutcheon
Errata in Document NO: IRG/WP/472
1981 - IRG/WP 483
L N Santhakumaran, J C Jain
Finishes for outdoor timbers
1975 - IRG/WP 378
Penichroa fasciata (Stephens) (Col. Cerambycidae) a pest in wood materials
1988 - IRG/WP 1365
Penichroa fasciata (Stephens) (Col. Cerambycidae) is found to be a frequent pest occurring in hardwood in storage in Italy. This paper reports the characteristic for identification, biological features, distribution and timber liable to attack.
A Gambetta, E Orlandi.
Fungal and bacterial attack of CCA-treated Pinus radiata timbers from a water-cooling tower
1991 - IRG/WP 1488
Transmission electron microscopy of decaying CCA-treated Pinus radiata timbers from an industrial water cooling tower showed presence of a thick biofilm covering some areas of the wood. The biofilm contained various morphologically distinct forms of microorganisms embedded in a slime. The study provided evidence of the activity of soft rot fungi and tunnelling and erosion bacteria in wood cells. The extent of damage to wood cells due to microbial activity varied, combined fungal and bacterial attack having the most damaging impact.
A P Singh, M E Hedley, D R Page, C S Han, K Atisongkroh
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 3: Full penetration of the refractory sapwood of white cypress
2000 - IRG/WP 00-40167
The heartwood of white cypress, Callitris glaucophylla, is renowned for its termite resistance and durability against decay. The sapwood, which can represent up to 30% of log volume, is non-durable and refractory to conventional preservative treatment. Previous work ascribes the lack of permeability to oily deposits within tracheids and ray cells. Environmental scanning electron microscopy was used to investigate ultrastructural aspects of sapwood permeability. Several pre-treatment processes to improve permeability were tested with limited success. Solvent drying allowed preservative penetration but damaged the structure of the timber. Neither, long term water soaking nor an oscillating pressure/vacuum cycle had any effect on porosity to water-borne treatments. Through extensive modifications to a standard VPI process we can now repeatedly achieve full penetration with organic solvent-based wood preservative solutions into white cypress sapwood. Effects of this process on the strength of the timber are being evaluated. Work is continuing as to the most effective and efficient treatment schedule and the latest results will be presented at IRG 31.
M J Kennedy, L M Stephens, M A Powell
Report on the monographic card on Coniophora puteana
1973 - IRG/WP 114
Problem of the treatment of dried sawn spruce building timbers with water-borne preservatives. Interim reports for discussion at the 4th Annual Meeting in West Berlin on 27 October 1972
1972 - IRG/WP 311
One of the most difficult technical problems facing the preservation industry is how to improve the treatment of refractory species of timber such as spruce. Its resistance to penetration, even under pressure' precludes its use for more hazardous service situations, and even in less severe conditions a higher level of treatment would be desirable. The importance of this subject led us to look once again at possible ways of improving treatment.
W Liese, J W W Morgan, T Hof, R O Ullevålseter
Monographic information on Lentinus lepideus.markup
1973 - IRG/WP 121
G Seehann, W Liese
The susceptibility of 35 Amazon wood species to Cryptotermes brevis (Walker)
1982 - IRG/WP 1160
Laboratory tests were carried to evaluate the susceptibility of 35 Amazon hardwoods to Cryptotermes brevis (Walker). The results were analysed statistically and showed that five wood species were non resistant, nine were resistant and the other twenty-one in between those classes of resistance.
M D Canedo
Some observations on Chlorophora pilosus Forst. var. glabromaculatus Goeze (Coleoptera, Cerambycidae)
1980 - IRG/WP 1119
Recent soft-rot research in softwoods and hardwoods
1980 - IRG/WP 1108
The purpose of this paper is to describe briefly the current status of our research on soft-rot fungi. The work to be discussed is still in progress and any results described must be regarded as provisional.
J A Butcher